Microbiology Flashcards

Question

organisms not covered by cephalosporins

Answer 1

they are LAME. Listeria, Atypicals (Chlamydia, mycoplasma), MRSA, and Enterococci. Exception: ceftaroline covers MRSA.

Answer 2

cefazolin and cephalexin- gram positive cocci (staph and strept), Proteus mirabilis, E coli, Klebisella pneumoniase (PEcK). Cefazolin is used prior to surgery to prevent S. aureus wound infections.

Answer 3

cefoxitin, cefaclor, cefusoxime- gram positive cocci, Haemophilus infleunzae, enterobacter aerogenes, Neisseria spp, Proteus mirabilis, E coli, Klebisella pneumoniase, Serratia marcescens (HEN PEcKS).

Answer 4

ceftriaxone, cefotaxime, ceftazidime- serious gram negative infections resistant to other beta lactams. Ceftriaxone- menigitis, gonorrhea, disseminated lyme disease. Cetazidime- pseudomonas.

Answer 5

cefepime- gram negative organisms with increased activity against Pseudomonas and gram positive organisms.

Answer 6

ceftaroline- broad gram positive and gram negative spectrum, including MRSA; does not cover pseudomonas

Answer 7

hypersensitivity reactions, autoimmune hemolytic anemia, disulfiram like reaction, vitamin K deficiency. Exhibit cross reactivity with penicillins. increased nephrotoxicity of aminoglycosides.

Answer 8

structural changes in penicillin binding proteins (transpeptidases).

Answer 9

imipenem, meropenem, ertapenem, doripenem

Answer 10

Imipenem is a broad spectrum, beta lactamase resistant carbapenem, Always administered with cilastatin (inhibitor of renal dehydropeptidase I) to decrease inactivation of drug in renal tubules.

Answer 11

gram positive cocci, gram negative rods and anaerobes. wide spectrum but significant side effects limit use to life threatening infections or after other drugs have failed. Meropenem has a decreased risk of seizures and is stable to dehydropeptidase I.

Answer 12

GI distress, skin rash, and CNS toxicity (seizures) at high plasma levels.

Answer 13

less susceptible to beta lactamases. prevents peptidoglycan cross-linking by binding to penicillin binding protein 3. Synergistic with aminoglycosides. No cross allergenicity with penicillin.

Answer 14

gram negative rods only. no activity against gram positives or anaerobes. For penicillin allergic patients and those with renal insufficiency who cannot tolerate aminoglycosides.

Answer 15

nontoxic, GI upset

Answer 16

inhibits cell wall peptidoglycan formation by binding D-ala D-ala portion of cell wall precursors. Bactericidal. Not susceptible to beta lactamases.

Answer 17

gram positive bugs only- serious, multidrug resistant organisms, including MRSA, S epidermidis, sensitive Enteroccocus species, and C diff (oral dose for pseudomembranous colitis).

Answer 18

well tolerated in general but not trouble free. Nephrotoxicity, ototoxicity, thrombophlebitis, diffuse, flushing-- red man syndrome (can largely prevent by pretretment with antihistamines and slow infusion rate).

Answer 19

occurs in bacteria via amino acid modification of D ala D ala to D ala D lac.

Answer 20

gentamicin, neomycin, amikacin, tobramycin, streptomycin

Answer 21

bactericidal, irreversible inhibition of intiation of comples through binding of the 30s subunit. can cause misreading of mRNA. Also block translocation. require O2 for uptake; therefore ineffective against anaerobes.

Answer 22

severe gram negative rod infections. Synergistic with beta lactam antibiotics. Neomycin for bowel surgery.

Answer 23

nephrotoxicity, neuromuscular blockade, ototoxicity (especially when used with loop diuretics). Teratogen

Answer 24

bacterial transferase enzymes inactivate the drug by acetylation, phosphorylation, or adenylation

Answer 25

bacteriostatic, bind to 30s and prevent attachment of aminoacyl tRNA; limited CNS penetration. Doxycyline is fecally eliminated and can be used in patients with renal failure. Do not take tetracyclines with milk (Ca), antacids (Ca or Mg), or iron containing preparations because divalent cations inhibit drugs absorption in the gut.

Answer 26

Borrlia burgdorferi, M pneumoniase. Drugs' ability to accumulate intracellularly makes them very effective against Rickettsia and Chlamydia. Also used to treat acne.

Answer 27

GI distress, discoloration of teeth and inhibition of bone growth in children, photosensitivity. Contraindicated in pregnancy.

Answer 28

decreased uptake or increased efflux out of bacterial cells by plasmid encoded transport pumps

Answer 29

blocks peptidyltransferase at 50s ribosomal subunit. bacteriostatic.

Answer 30

meninigitis (haemophlus influenzae, Neisseria meningitidis, Streptococcus pneumoniase) and Rocky mountain spotted fever (rickesttsia rickettsii) Limited use owing to toxicities, but often still used in developing countries

Answer 31

plasmid encoded acetyltransferase inactivates the drug

Answer 32

blocks peptide transfer (translocation) at 50s ribosomal subunit. Bacteriostatic

Answer 33

anaerobic infections (e.g. Bacteroides sp, Clostridium perfringens) in aspiration pneumonia, lung abscesses and oral infections. Also effective against invasive group A streptococcal infection. Treats anaerobic infections above the diaphragm vs. metronidazole (anaerobic below the diaphragm).

Answer 34

pseudomembranous colitis (C diff), fever, diarrhea

Answer 35

inhibit protein synthesis by binding to 50S subunit and preventing formation of the initiation complex

Answer 36

gram positive species including MRSA and VRE

Answer 37

bone marrow suppresion (especially thrombocytopenia), peripheral neuropathy, serotonin syndrome

Answer 38

point mutation of rRNA

Answer 39

azithromycin, clarithromycin, erythromycin

Answer 40

inhibition of protein synthesis by blocking translocation; bind to the 23S rRNA of the 50S subunit. Bacteriostatic

Answer 41

Atypical pneumonias (mycoplasma, chlamydia, legionella), STIs (chlamydia), gram positive cocci (streptococcal infections in patients allergic to penicillin), B. pertussis.

Answer 42

MACRO: gastrointestinal Motility, Arrhythmia caused by prolong QT interval, acute Cholestatic hepatitis, Rash, eOsinophilia. Increases serum concentration of theophyllines, oral anticoagulants. Clarithromycin and erthromycin inhibit cytochrome P-450.

Answer 43

methylation of 23S rRNA binding site prevents binding of drug

Answer 44

inhibits bacterial dihydrofolate reductase. Bacteriostatic

Answer 45

used in combination with sulfonamides (TMP-SMX), causing sequential block of folate synthesis. Combination used for UTIs, Shigella, Salmonella, Pneumocystis jirovecii pneumonia treatment and prophylaxis, toxoplasmosis prophylaxis

Answer 46

megloblastic anemia, leukopenia, granulocytopenia (may alleviate with supplemental folinic acid. TMP Treats Marrow Poorly.

Answer 47

inhibit folate synthesis. Para-aminobenzoic acid (PABA) antimetabolites inhibit dihydropteroate synthase. Bacterostatic (bacteriocidal when used with TMP). Dapsone, used to treat lepromatous leprosy, is closely related drug that also inhibits folate synthesis.

Answer 48

gram positive, gram negative, Nocardia, Chlamydia. Triple sulfas or SMX for simple UTI.

Answer 49

hypersensitivity reactions, hemolysis if G6PD deficient, nephrotoxicity (tubulointerstitial nephritis), photosensitivity, kernicterus in infant, displace other drugs from albumin (e.g. warfarin)

Answer 50

altered enzyme (bacterial dihydropteroate synthase), decrease uptake or increase PABA synthesis.

Answer 51

ciprofloxacin, norfloxacin, levofloxacin, olfoxacin, mociflocacin, gemifloxacin, enoxacin

Answer 52

inhibit prokaryotic enzymes topoisomerase II (DNA gyrase) and topoisomerase IV. bactericidal. Must not be taken with antacids.

Answer 53

gram negative rods of urinary and GI tracts (including pseudomonas), Neisseria, some gram positive organism.

Answer 54

GI upset, superinfections, skin rashes, headache, dizziness, Less commonly, can cause leg cramps and myalgias. Contraindicated in pregnancy, while nursing, and children under 18 years due to possible cartilage damage. Some may prolong QT interval. May cause tendonitis or tendon rupture in people over 60 and in patients taking prednisone. Fluoroquinolones hurt attachments to your bones.

Answer 55

chromosome encoded mutation in DNA gyrase, plasmid mediated resistance, efflux pumps.

Answer 56

lepopeptide that disrupts cell membrane of gram positive cocci

Answer 57

S aureus skin infections (especially MRSA), bacteremia, endocarditis, VRE. Not used for pneumonia (avidly binds to and is inactivated by surfactant).

Answer 58

myopathy, rhabdomyolysis

Answer 59

forms toxic free radical metabolites in bacterial cell that damage DNA. Bactericidal, antiprotozoal

Answer 60

treats Giardia, Entamoeba, Trichomonas, Gardnerella vaginalis, Anaerobes (Bacteroides, C. diff). Used with a proton pump inhibitor and clarithromycin for triple therapy for triple therapy against H. Pylori. Treats anaerobic infections below the diaphragm vs clindamycin.

Answer 61

Rifamin, Isoniazid, Pyrazinamide, Ethambutol (RIPE for treatment)

Answer 62

azithromycin, rifabutin

Answer 63

more drug resistant than M tuberculosis. Azithromycin or clarithromycin plus ethambutol. Can add rifabutin or ciproflaxacin

Answer 64

long term treatment with dapsone and rifampin for tuberculoid form. Add clofazimine for lepromatous form

Answer 65

rifampin rifabutin

Answer 66

Inhibit DNA dependent RNA polymerase

Answer 67

RNA polymerase inhibitor, ramps up microsomal cytochrome P-450, red/orange body fluids, rapid resistance if use alone. Rifampin ramps up cytochrome P450 but rifabutin does not.

Answer 68

M. tuberculosis; delay resistance to dapsone when used for leprosy. Used for meningococcal prophylaxis and chemoprophylaxis in contacts of children with Haemophilus influenzae type B.

Answer 69

Minor hepatotoxicity and drug interactions (increase cytochrome P450); orange body fluids. Rifabutin favored aver rifampin in patients with HIV infections due to less P450 stimulation.

Answer 70

mutations reduce drug bindint to RNA polymerase. Monotherapy rapidly leads to resistance.

Answer 71

decrease synthesis of mycolic acids. bacterial catalase peroxidase (encoded by KatG) needed to convert INH to active metabolite

Answer 72

Mycobacterium tuberculosis. The only agent used as solo prophylaxis against TB. Different half lives depending on fast vs slow acetylators

Answer 73

Neurotoxicity, hepatotoxicity, Pyridoxine (B6) can prevent neurotoxicity. INH Injures Nephrons and Hepatocytes.

Answer 74

Mutations leading to underexpression of Kat G

Answer 75

mechanism uncertain. Is a prodrug that is converted to active compound pyrazinoic acid.

Answer 76

Mycobacterium tuberculosis

Answer 77

Hyperuricemia, hepatoxicity

Answer 78

decrease carbohydrate polymerization of mycobacterium cell wall by blocking arabinosyltransferae

Answer 79

Mycobacterium tuberculosis

Answer 80

optic neuropathy (red- green color blindness)

Answer 81

staph and strep

Answer 82

moraxella catarrhalis, neisseria

Answer 83

bacillus, clostridium, corynebacterium, gardnerella, lactobacillus, listeria, mycobacterium (acid fast), propionibacterium

Answer 84

bacteroides, camylobacter, e coli, enterobacter, helicobacter, klebsiella, proteus, pseudomonas, salmonella, serratia, shigella, vibrio, yersinia

Answer 85

bordetella, haemophilus (pleomorphic), legionella (silver stain).

Answer 86

bartonella, brucella, francisella, pasteurella

Answer 87

actinomyces, nocardia (weakly acid fast)

Answer 88

chlamydia (giemsa), rickettsiae (giemsa)

Answer 89

borrelia (giemsa), leptospira, treponema

Answer 90

mycoplasma, ureaplasma (contain sterols, which do not gram stain)

Answer 91

treponema, mycobacteria, mycoplasma, legionella pneumophila, rickettsia, chlamydia

Answer 92

chlamydia, borrelia, rickettsia, trypanosomes, plasmodium

Answer 93

stains glycogen, mucopolysaccharides; diagnosis whipple disease

Answer 94

acid fast bacteria (nocardia, mycobacteria, protozoa (cryptosporidium oocysts). auramine rhodamine stain is an alternative

Answer 95

cryptococcus neoformans (mucicarmine can also be used to stain think polysaccharide capsule red)

Answer 96

fungi (pneumocystis), legionella, H pylori

Answer 97

H influenzae and Neisseria. Has factor V (NAD+) and X (hematin)

Answer 98

N. gonorrhoeae, N meningitidis. Contains vancomycin (inhibits gram positive organisms), trimethoprim, colistin (inhibits gram negative organisms except neisseria), and Nystatin (inhibits fungi)

Answer 99

B pertussis, contains potato

Answer 100

B pertussis, contains charcoal, blood, and antibiotic

Answer 101

c diphtheriae

Answer 102

m tuberculosis

Answer 103

m pneumoniae, requires cholesterol

Answer 104

lactose fermenting enterics, fermentation produces acid, causing colonies to turn pink

Answer 105

E coli, colonies with green metallic sheen

Answer 106

legionella

Answer 107

Nocardia, Pseudomonas aeruginosa, and mycobacterium tuberculosis. reactivation of M tuberculosis (eg after immunocompromise or TNF-alpha inhibitor use) has a predilection for the apices of the lung which have the highest pO2.

Answer 108

fusobacterium, clostridium, bacteroides, and actinomyces. They lack catalase and/or superoxide dismuase and are thus susceptible to oxidative damage. Generally foul smelling (short chain fatty acids), are difficult to culture and produce gas in tissue (CO2 and H2). They are normal flora in GI tract, typically pathogenic elsewhere. Aminoglycosides are ineffective against anaerobes because these antibiotics require O2 to enter into bacterial cell.

Answer 109

rickettsia, chlmydia, coxiella (C burnetti, Q fever). relay on host ATP

Answer 110

salmonella, neisseria, brucella, mycobacterium, listeria, francisella, legionella, yersinia pestis.

Answer 111

hamophilus influenzae type B, neisseria meningitidis, Escherichia coli, salmonella, klebsiella pneumoniae, and group B strep. their capsules serve as an antiphagocytic virulence factor. Capsule plus protein conjugate serves as an antigen in vaccines. They are opsonized then cleared by spleen. Asplenics have decreased opsonizing ability and thus increase risk for severe infections. Give S. pneumoniae, H influenzae, N meningitidis vaccines.

Answer 112

some vaccines containing polysaccharide capsule antigens are conjugated to a carrier protein, enhancing immunogenisity by promoting T cell activation and subsequent class switching. A polysaccharide antigen alone cannot be presented to T cells. examples include pneumococcal, H influenzae type B, meningococcal vaccine.

Answer 113

cryptococcus, H pylori, Proteus, Ureaplasma, Nocardia, Klebsiella, S epidermidis, S saprophyticus.

Answer 114

catalase degrades H2O2 into H2O and bubbles of O2 before it can be converted to microbicidal products by the enzymes myeloperoxidase. People with chronic granulomatous disease (NADPH oxidase deficiency) have recurrent infections with certain catalase positive organisms. Examples include Nocardia, Pseudomonas, Listeria, Aspergillus, Candida, E coli, Staphylococci, Serratia

Answer 115

actinomyces

Answer 116

pseudomonas aeruginosa

Answer 117

serratia marcescens

Answer 118

binds Fc region of IgG. Prevents opsonization and phagocytosis. Expressed by S aureus.

Answer 119

enzymes that cleaves IgA. Secreted by S pneumoniae, H influenze type B and Neisseria in order to colonize respiratory mucosa.

Answer 120

helps prevent phagocytosis. Expressed by group A streptococci. Shares similar epitopes to human cellular proteins (molecular mimicry); possibly underlies the autoimmune response seen in acute rheumatic fever.

Answer 121

also known as injectisome. needle like protein appendage facilitating direct delivery of toxins from certain gram negative bacteria (eg pseudomonas, salmonella, shigella, E coli) to eukaryotic host cell.

Answer 122

secreted by certain species of gram positive and gram negative bacteria, composed of polypeptide, gene located on plasmid or bacteriophage. Highly toxic. Induces high titer antibodies called antitoxins. Toxoids are used as vaccines. Destroyed rapidly at 60 degrees C (except staph enterotoxin). Typical disease include tetanus, botulism, diphteria.

Answer 123

outer cell membrane of most gram negative bacteria. Composed of lipopolysaccharide (structural part of bacteria; released when lysed). Gene located within bacterial chromosome. Low toxicity. Can cause fever, shock, and activates tissue factor leading to DIC. Activates macrophages to release TNF alpha (fever and hypotension), IL-1 (fever), IL-6, and nitric oxide (hypotension). Activates complement C3a leading to hypotension and edema and C5a leading to neutrophil chemotaxis. Poorly antigenic. No toxoids formed and no vaccine available. Stable at 100 degrees C for 1 hour. Typical diseases include meningococcemia, sepsis by gram negative rods. O-antigen

Answer 124

released by cornebacterium diphtheriae. Inactivate elongation factor (EF-2). Causes pharyngitis with pseudomembranes in throat and severe lymphadenopathy (bull neck).

Answer 125

released by pseudomonas aeruginosa. Inactivate elongation factor (EF-2). Causes host cell deathe

Answer 126

released by shigella spp. inactivates 60S ribosome by removing adenine from rRNA. GI mucosal damage causes dysentery; ST also enhances cytokine release, causing hemolytic-uremic syndrome (HUS).

Answer 127

released by enterohemorrhagic E coli (EHEC). inactivates 60S ribosome by removing adenine from rRNA. SLT enhances cytokine release, causing HUS (prototypically in EHEC serotype O157:H7). Unlike shigella, EHEC does not invade host cells.

Answer 128

released by enterotoxigenic E coli (ETEC). Overactivates adenylate cyclase (increases cAMP) leading to increase Cl secretion in gut and H2O efflux. Causes watery diarrhea. Labile in the Air (Adenylate cyclase).

Answer 129

released by enterotoxigenic E coli (ETEC). Overactivates guanylate cyclase (increases cGMP) leading to decrease resorption of NaCl and H2O in gut. Causes watery diarrhea. Stable on the Ground (guanylate cyclase).

Answer 130

released by bacillus anthracis. Mimics the adenylate cyclase (increases cAMP). Likely responsible for characteristic edematous borders of black eschar in cutaneous anthrax.

Answer 131

released vibrio cholerae. Overactivates adenylate cyclase (increases cAMP) by permanently activating Gs leading to increase Cl secretion in gut and H2O efflux. Causing voluminous rice water diarrhea.

Answer 132

released by bordetella pertussis. Overactivates adenylate cyclase (increases cAMP) by disabling Gi, impairing phagocytosis to permit survival of microbe. May not be the cause the cough in whooping cough. can cause 100 day cough in adults.

Answer 133

released by Clostridium tetania. A protease that cleaves SNARE (soluble NSF attachment protein receptor), a set of proteins required for neurotransmitter release via vesicular fusion. Causes spasticity, risus sardonicus and lock jaw; toxin prevents release of inhibitory (GABA and glycine) neurotransmitters from Renshaw cells.

Answer 134

released by clostridium botulinum. A protease that cleaves SNARE (soluble NSF attachment protein receptor), a set of proteins required for neurotransmitter release via vesicular fusion. Causes flaccid paralysis, floppy baby; toxin prevents release of stimulatory (ACh) signals at neuromuscular junctions leading to flaccid paralysis.

Answer 135

releasing Clostridium perfringens. Phospholipase (lecithinase) that degrades tissue and cell membranes. Causes degradation of phospholipids leading to myonecrosis (gas gangrene) and hemolysis (double zone of heomlysis on blood agar).

Answer 136

released by streptococcus pyogenes. A protein that degrades cell membrane. Causes lyses RBCs; contributes to beta- hemolysis; host antibodies against toxin (ASO) used to diagnose rheumatic fever (do not confuse with immune complexes of poststreptococcal glomerulonephritis).

Answer 137

released by staphylococcus aureus. Binds to MCH II and TCR outside of antigen binding site to cause overwhelming release of IL-1, IL-2, IFN-gamma, TNF-alpha leading to shock. Causes toxic shock syndrome: fever, rash, shock,; other toxins cause scalded skin syndrome (exfoliative toxin) and food poisoning (enterotoxin).

Answer 138

released by streptococcus pyogenes. s. Binds to MCH II and TCR outside of antigen binding site to cause overwhelming release of IL-1, IL-2, IFN-gamma, TNF-alpha leading to shock. Causes toxic shock syndrome: fever, rash, and shock.

Answer 139

takes up naked DNA from environment.

Answer 140

plasmid becomes incorporated into host.

Answer 141

Segment of DNA that can jump from one location to another. Can transfer from plasmid to chromosome or vice versa.

Answer 142

generalized transduction occurs when lytic phage infects bacterium, leading to cleavage of bacterial DNA. Specialized transduction occurs when a lysogenic phage infects bacterium; viral DNA incorporates into bacterial chromosome. when phage DNA is excised and can infect another bacterium. Shiga like toxin, botulinum toxin, cholera toxin, diphteria toxin, and eythrogenic toxin are encoded in lysogenic phages.

Answer 143

with novobiocin, saprophyticus is resistant and epidermidis is sensitive

Answer 144

with optochin, viridans is resistant; pneumoniae is sensitive. With bacitracin, group B are resistant; group A strep are sensitive.

Answer 145

form green ring around colonies on blood agar. Includes the following organisms: Streptococcus pneumoniae (catalase negative and optochin sensitive), Viridans streptococci (catalase negative and optochin resistant).

Answer 146

form clear area of hemolysis on blood agar. Includes the following organisms: Staphylococcus aureus (catalase and coagulase positive), Streptococcus pyogenes- group A strep (catalase negative and bacitracin sensitive), Streptococcus agalactiae- group B strep (catalase negative and bacitracin resistant), and Listeria monocytogenes (tumbling motility, meningitis in newborns, unpasteurized milk).

Answer 147

Gram +, cocci in clusters, catalase +, coagulase +, β-hemolytic, forms yellow/golden colonies (aurei="golden"). gram positive cocci in clusters. protein A (virulence factor) binds Fc-IgG, inhibiting complement activation and phagocytosis. Commonly colonizes the nares.

Answer 148

Inflammatory disease- skin infections, organ abscesses, pneumonia (often after influenza virus infection), endocarditis, septic arthritis, and osteomyelitis. Toxin mediated disease- toxic shock syndrome, scalded skin syndrome (exfoliative toxin), rapid onset food poisoning (enterotoxins). MRSA (methicillin resistant S aureus) infection- important cause of serious nosocomial and community acquired infections; resistant to methicillin and nafcillin because of altered penicillin binding protein. TSST is a superantigen that binds to MHC II and T cell receptor, resulting in polyclonal T cell activation. Staphylococcal toxic shock syndrome (TSS) presents as fever, vomiting, rash, desquamation, shock, end organ failure. Associated with prolonged use of vaginal tampons or nasal packing. Compare with Streptococcus pyogenes TSS (a toxic shock like sydrome associated with painful skin infection). S aureus food poisoning due to ingestion of preformed toxin leading to short incubation period (2-6hrs) followed by nonbloody diarrhea and emesis. Enterotoxin is heat stable, cannot be destroyed by cooking. Staph aureus makes coagulase and toxins. Forms fibrin clot around self leading to abscess.

Answer 149

Staphylococcus epidermidis is a catalase-positive, coagulase-negative, urease-positive, non-hemolytic with white colonies, gram-positive cocci that grows in clusters. infects prothetic devices (eg hip implant, heart valve) and intravenous catheters by producing adherent biofilms. Component of normal skin flora; contaminates blood cultures. Novobiocin sensitive.

Answer 150

Staphylococcus saprophyticus is a facultative anaerobe, urease-positive, gram-positive, catalase-positive coccus. secound most common cause of uncomplicated UTI in young women (first is E coli). Novobiocin resistant.

Answer 151

Streptococcus pneumoniae is a facultative anaerobic, optochin-sensitive gram-positive diplococci. most common cause of meningitis, otitis media (in children), pneumonia, sinusitis. lancet shaped, gram positive diplococci. Encapsulated. IgA protease. Most are optochin sensitive. Pneumococcus is associated with rusty sputum, sepsis in sickle cell disease and splectomy. No virulence without capsule.

Answer 152

alpha hemolytic. They are normal flora of the oropharynx that cause dental caries (streptococcus mutans) and subacute bacterial endocarditis at damaged heart valves (S sanguinis). Resistant to optochin, differentiating them from S pneumoniae, which is alpha hemolytic but optochin sensitive. S sanguinis makes dextrans, which bind to fibrin platelet aggregates on damaged heart valve. Viridans group strep live in the mouth because they are afraid of the chin (opto-chin resistant).

Answer 153

group A strep causes: pyogenic- pharyngitis, cellulitis, impetigo, and erysipelas. Toxigenic- scarlet fever, toxic shock like syndrome, necrotizing fasciitis. Immunologic- rheumatic fever, acute glomerulonephritis.

Answer 154

Streptococcus pyogenes (Group A Strep, GAS) is a facultative anaerobic, β-hemolytic, gram-positive cocci. bacitracin sensitive, pyrrolidonyl arylamidase (PYR) positive. Antibodies to M protein enhance host defenses against S pyogenes but can give rise to rheumatic fever. ASO titer detects recent S pyogenes infection. Pharyngitis can result in rheumatic fever and glomerulonephritis. Impetigo more commonly recedes glomerulonephritis than pharyngitis.

Answer 155

caused by Streptococcus pyogenes (group A streptococci). Jones: joints- polyarthritis, heart- carditis, nodules (subcutaneous), erythema marginatum, sydenham chorea.

Answer 156

caused by Streptococcus pyogenes (group A streptococci). Scarlet rash with sandpaper like texture, strawberry tongue, circumoral pallor, subsequent desquamation.

Answer 157

Streptococcus agalactiae (GBS, Group B streptococcus) is a catalase negative gram-positive cocci with beta hemolysis on blood agar. bacitracin resistant, colonizes vagina; causes pneumonia, meningitis, and sepsis, mainly in babies. Produces CAMP factor, which enlarges the area of heomlysis formed by S aureus. Hippourate test positive. Screen pregnant women at 35-37 weeks of gestation. Patients with positive culture should receive intrapartum penicillin prophylacxis. Group B for babies.

Answer 158

Enterococci (E faecalis and E faecium) are normal colonic flora that are penicillin G resistant and cause UTI, biliary tract infections, and subacute endocarditis (following GI/GU procedures). Lancefield group D includes the enterococci and the nonenterococci group D streptococci. Variable hemolysis. VRE (vancomycin resistant enterococci) are an important cause of nosocomial infection. Enterococci, hardier than nonenterococcal group D, can grow in 6.5% NaCl and bile. Entero= intestine, faecalis=feces, strepto= twisted (chains), coccus=berry.

Answer 159

Streptococcus gallolyticus (formerly S. bovis) is catalase-negative, gram-positive coccus. colonizes the gut, but not apart of regular flora. S gallolyticus (S bovis biotype 1) can cause bacteremia and subacute endocarditis and is associated with colon cancer.

Answer 160

Corynebacterium diphtheriae is an aerobic, non-sporeforming gram-positive bacillus. causes diphtheria via exotoxin encoded by beta-prophage. Potent exotoxin inhibits protein synthesis via ADP-ribosylation of EF-2. Symptoms include pseudomembranous pharyngitis (grayish-white membrane) with lymphadenopathy, myocarditis, and arrhythmias. Lab diagnosis based on gram positive rods with metachromatic (blue and red) granules and a positive Elek test for toxin. Toxoid vaccines prevent diphtheria. Coryne=club shaped. Black colonies on cystine-tellurite agar. ABCDEFG: ADP-ribosylation, Beta-prophage, Corynebacterium, Diphtheriae, Elongation factor 2, Granules.

Answer 161

formed when nutrients are limited. They are highly resistant to heat and chemicals. Have dipicolinic acid in their core. Have no metabolic activity. Must autoclave to potentially kill spores by steaming at 121 degrees Celsius for 15 min. Species and diseases include: Bacillus anthracis (anthrax), Bacillus cereus (food poisoning), Clostridium botulinum (botulism), Clostridium difficile (antibiotic associated colitis), Clostridium perfringens (gas gangrene), Clostridium tetani (tetanus), Coxiella burnetii (Q fever).

Answer 162

gram positive, spore forming, obligate anaerobic bacilli.

Answer 163

gram positive, spore forming, obligate anaerobic bacilli. Produces tetanospasmin, an exotoxin causing tetanus. Tetanus toxin (and botulinum toxin) are proteases that cleave SNARE proteins for neurotransmitters, GABA and glycine, from Renshaw cells in spinal cord. Causes spastic paralysis, trismus (lockjaw), risus sardonicus (raised eyebrows and open grin). Prevent with tetanus vaccine. Treat with antitoxin with or without vaccine booster, diazepam (for muscle spasms).

Answer 164

gram positive, spore forming, obligate anaerobic bacilli. Produces a preformed, heat labile toxin that inhibits ACh release at the neuromuscular junction, causing botulism. In adults, disease is caused by ingestion of preformed toxin. In babies, ingestions of spores in honey causes disease (floppy baby syndrome). Treat with antitoxin

Answer 165

gram positive, spore forming, obligate anaerobic bacilli. produces alpha toxin (lecithinase, a phospholipase) that can cause myonecrosis (gas gangrene) and hemolysis. Perfringens perforates a gangrenous leg.

Answer 166

gram positive, spore forming, obligate anaerobic bacilli. Produces two toxins. Toxin A, enterotoxin, binds to the brush border of the gut. Toxin B, cytotoxin, causes cytoskeletal disruption via actin depolymerization leading to pseudomembranous colitis causing diarrhea. Often secondary to antibiotics, especially clindamycin or ampicillin. Diagnosed by detection one or both toxins in stool by PCR. Treat with metronidazole or oral vancomycin. For recurrent cases, consider repeating prior regimen, fidaxomicin or fecal microbiota transplant.

Answer 167

caused by Bacillus anthracis, a gram positive, spore forming rod that produces anthrax toxin. The only bacterium with a polypeptide capsule (contains D glutamate).

Answer 168

painless papule surrounded by vesicles causing ulcer with black eschar (painless, necrotic) and can uncommonly progress to bacteremia and death.

Answer 169

inhalation of spore, which causes flu like symptoms that rapidly progress to fever, pulmonary hemorrhage, mediastinitis and shock.

Answer 170

Bacillus cereus is an endemic, soil-dwelling, Gram-positive, rod-shaped, motile, beta hemolytic bacterium. causes food poisoning. Spore survive cooking rice. Keeping rice warm results in germination of spores and enterotoxin formation. Emetic type usually seen with rice and pasta. Nausea and vomiting within 1-5 hr. Caused by cereulide, a preformed toxin. Diarrheal type causes watery, nonbloody diarrhea and GI pain within 8-18 hr. Reheated rice syndrome.

Answer 171

Listeria monocytogenes is a non-spore forming beta-hemolytic, catalase-positive gram-positive bacillus. facultative intracellular microbe; acquired by ingestion of unpasteurized diary products and cold deli meats, via transplacental transmission, or by vaginal transmission during birth. Forms rocket tails (via actin polymerization) that allow intracellular movement and cell to cell spread across cell membranes, thereby avoiding antibody. Characteristic tumbling motility; is only gram positive organism to produce endotoxin. Can cause amnionitis, septicemia, and spontaneous abortion in pregnant women; granulomatosis infantiseptica; neonatal meningitis; meningitis in immunocompromised patients; mild gastroenteritis in health individuals. Treatment: gastroenteritis is usually self limited; ampicillin in infants, immunocompromised, and the elderly as empirical treatment of meningitis.

Answer 172

Like Nocardia, forms long, branching filaments resembling fungi. Gram positive anaerobe, not acid fast, located in normal oral flora, causes oral/facial abscesses that drain through sinus tracts, forms yellow "sulfur granules". Treat with penicillin. Treatment is a SNAP: Sulfonamides for Nocardia; Actinomyces treated with Penicillin

Answer 173

Like Actinomyces, forms long, branching filaments resembling fungi. Gram positive aerobe, acid fast (weak), found in soil, causes pulmonary infections in immunocompromised and cutaneous infections after trauma in immunocompetent. Treat with sulfonamides. Treatment is a SNAP: Sulfonamides for Nocardia; Actinomyces treated with Penicillin

Answer 174

Due to infection with mycobacterium tuberculosis, in nonimmune host (usually a child). Causes hilar nodes and Ghon focus, usually found in lower to mid zones of the lung. There are several different potential outcomes: Ghon complex can heal by fibrosis leading to immunity, hypersensitivity, and a tuberculin positive test. It can also progress to lung disease, usually in HIV patients or those who have malnutrition; can progress to death rarely. It can also cause severe bacteremia, causing miliary tuberculosis and death. It can also result in preallergic lymphatic or hematogenous dissemination, leading to dormant tubercle bacilli in several organs, which can reactivate in adult life.

Answer 175

can be located in CNS (parenchymal tuberculoma or meningitis), vertebral body (Pott disease), lymphadenitis, renal, GI, adrenals. Can reactivate later in lungs.

Answer 176

Due to reactivation or reinfection with mycobacterium tuberculosis, in partially immune hypersensitized host (usually adult). Causes fibrocaseous cavitary lesion, usually in upper lobes.

Answer 177

positive test shows current or past infection with mycobacterium tuberculosis. False positives with BCG vaccination. negative test if no infection or anergic (steroids, malnutrition, immunocompromise) and in sarcoidosis.

Answer 178

positive test shows current or past infection with mycobacterium tuberculosis. fewer false positives from BCG vaccination.

Answer 179

has central necrosis with multinucleated Langhans giant cell. This appearance is classic for TB, but may be seen in fungal infections as well.

Answer 180

causes TB, often resistant to multiple drugs. Symptoms include fever, night sweats, weight loss, cough (nonproductive or productive), hemoptysis.

Answer 181

a genus of gram-positive, aerobic, acid-fast bacteria, occurring as slightly curved or straight rods. Produce cord factor in virulent strains, which inhibits macrophage maturation and induces release of TNF-alpha (causes acute phase reaction). Sulfatides (surface glycolipids) inhibit phagolysosomal fusion.

Answer 182

causes disseminated non-TB disease in AIDS; often resistant to multiple drugs. Prophylaxis with azithromycin when CD4+ count is below 50 cells/mm3.

Answer 183

cervical lymphadenitis in children.

Answer 184

hand infection in aquarium handlers

Answer 185

cause by Mycobacterium leprae, an acid fast bacillus that likes cool temperatures (infects skin and superficial nerves, leading to glove and stocking loss of sensation) and cannot be grown in vitro. Reservoir in United States: armadillos. Has two forms: lepromatous and tuberculoid.

Answer 186

cause by Mycobacterium leprae, an acid fast bacillus. presents diffusely over the skin, with leonine (lion like) facies and is communicable; characterized by low cell mediated immunity with a humoral Th2 response. Treatment is dapsone, rifampin, and chlofazimine. Can be lethal.

Answer 187

cause by Mycobacterium leprae, an acid fast bacillus. Limited to a few hypesthetic, hairless skin plaques; characterized by high cell mediated immunity with a largely Th1 type immune response. Treatment includes dapsone and rifampin.

Answer 188

fermentation of lactose leads to pink colonies on MacConkey agar. Examples include Citrobacter, Klebsiella, E coli, Enterobacter, and Serratia (weak fermenter). E coli produces beta-galactosidase, which breaks down lactose into glucose and galactose. On EMB agar, lactose fermenters grow as purple/black colonies. E coli grows colonies with a green sheen.

Answer 189

gram negative diplococci. Both gonococci and meningococci ferment glucose and produce IgA proteases. MeninGococci ferment Maltose and Glucose. Gonococci ferment Glucose.

Answer 190

gram negative diplococci. Unlike meningococci, it does not have a polysaccharide capsule, ferment maltose, and there is no vaccine due to antigenic variation of pilus proteins. It is sexually or perinatally transmitted. It can cause gonorrhea, septic arthritis, neonatal conjunctivitis, pelvic inflammatory disease (PID) and Fitz-Hugh-Curtis syndrome. Condoms decrease sexual transmission. Erthromycin ointment prevents neonatal transmission. Treatment includes ceftriaxone and either azithromycin or doxycycline for possible chlamydial coinfection.

Answer 191

gram negative diplococci. Unlike gonococci, it does have a polysaccharide capsule, ferment maltose, and there is vaccine (type B vaccine, not widely available). It is transmitted via respiratory and oral secretions. It causes meningococcemia and meningitis, Waterhouse- Friderichsen syndrome. Prophylaxis includes rifampin, ciprofloxacin, or ceftriaxone for close contacts. Treatment includes ceftriaxone or penicillin G.

Answer 192

Haemophilus influenzae is an encapsulated gram-negative coccobacilli. Small gram negative (coccobacillary) rod. Aerosal transmission. Nontypeable strains are the most common cause of mucosal infections (otitis media, conjuctivitis, bronchitis) as well as invasive infections since the vaccine for capsular type b was introduced. Produces IgA protease. Culture on chocolate agar, which contains factor V (NAD+) and X (hematin) for growth; can also be grown with S aureus, which provides factor V through the hemolysis of RBCs. haEMOPhilus causes Epiglottitis (cherry red in children), Meningitis, Otitis media, and Pneumonia. Treat mucosal infections with amoxicillin with or without clavulanate. Treat meningitis with ceftriaxone. Rifampin prophylaxis for close contacts. Vaccine contains type b capsular polysaccharide (polyribosylribitol phosphate) conjugated to diphtheria toxoid or other protein. Given between 2 and 18 months of age. Does not cause the flu (the influenza virus does).

Answer 193

Gram negative rod. Gram stains poorly, use silver stain. Grow on charcoal yeast extract culture with iron and cysteine. Detected by presence of antigen in urine. Labs may show hyponatremia. Aerosol transmission from environmental water source habitat (eg air conditioning systems, hot water tanks). No person to person transmission. Treat with macrolide or quinolone.

Answer 194

Caused by Legionella pneumophila. Causes severe pneumonia (often unilateral and lobar), fever, GI, and CNS symptoms

Answer 195

Caused by Legionella pneumophila. Causes mild flu like syndrome

Answer 196

Aerobic, motile, gram-negative rod. Non-lactose fermenting, oxidase positive. Produces pyocyanin (blue-green pigment); has a grape like odor. Produces endotoxin (fever, shock) and exotoxin A (inactivates EF-2). PSEUDDOmona is associated with: Pneumonia, Sepsis, otitis Externa (swimmers ear), UTIs, Diabetes, Drug use, Osteomyelitis (eg puncture wounds). Depending on source and severity, treatment may include: extended spectrum beta lactams (eg piperacillin, ticarcillin, cefepime), carbapenems (eg imipenem, meropenem), monobactams (eg aztrenam), fluoroquinolones (eg ciprofloxacin), aminoglycosides (eg gentamicin, tobramycin), for multidrug resistant strains: colistin, polymyxin B. AERuginosa=AERobic. Pseudomonas often occurs in burn victims. Mucoid polysaccharide capsule may contribute to chronic pneumonia in cystic fibrosis patients due to biofilm formation.

Answer 197

Caused by Pseudomonas aeruginosa. Rapidly progressive, necrotic cutaneous lesion caused by Pseudomonas bacteremia. Typically seen in immunocompromised patients.

Answer 198

Fimbriae causes cystitis and pyelonephritis; K capsule causes pneumonia, neonatal meningitis; LPS endotoxin causes septic shock.

Answer 199

Escherichia coli is a lactose fermenting, gram-negative, facultative anaerobic bacillus. Microbe invades intestinal mucosa and causes necrosis and inflammation. Clinical manifestations similar to Shigella. Causes dysentery

Answer 200

Escherichia coli is a lactose fermenting, gram-negative, facultative anaerobic bacillus. Produces heat labile and heat stable enteroToxins. No inflammation or invasion. Known as travelers diarrhea (watery)

Answer 201

Escherichia coli is a lactose fermenting, gram-negative, facultative anaerobic bacillus. No toxin produced. Adheres to apical surface, flattens villi, prevents absorption. Causes diarrhea, usually in children (Pediatrics).

Answer 202

Escherichia coli is a lactose fermenting, gram-negative, facultative anaerobic bacillus. also called STEC (shiga toxin producing E coli). O157:H7 is most common serotype in US. Shiga-like toxin causes hemolytic-uremic syndrome. Causes dysentery (toxin alone causes necrosis and inflammation). Does not ferment sorbitol (distinguishes EHEC from other E coli).

Answer 203

caused by shiga like toxin, secreted by EHEC. triad of anemia, thrombocytopenia, and acute renal failure due to microthrombi forming on damaged endothelium leading to mechanical hemolysis (with schistocytes on peripheral blood smear), platelet consumption, and decrease renal blood flow.

Answer 204

Klebsiella pneumoniae is an encapsulated, urease-positive, gram-negative, facultative anaerobic bacillus. An intestinal flora that causes lobar pneumonia in alcoholics and diabetics when aspirated. Very mucoid colonies caused by abundant polysaccharide capsules. Dark red currant jelly sputum (blood/mucus). Also causes nosocomial UTIs. The four A's of KlebsiellA: Aspiration pneumonia, Abscess in lungs and liver, Alcoholics, di-A-betics.

Answer 205

Campylobacter jejuni is a microaerophilic, comma-shaped, urease-negative, oxidase positive, motile, gram-negative bacillus. Major cause of bloody diarrhea, especially in children. Fecal-oral transmission through person-to-person contact or via ingestion of poultry, meat, unpasteurized milk. Contact with infected animals (dogs, cats, and pigs) is also a risk factor. Comma or S-shaped, oxidase positive, grows at 42 degrees Celsius. Common antecedent to Guillain-Barre syndrome and reactive arthritis.

Answer 206

Both Salmonella and Shigella are gram negative bacilli that are non lactose fermenters and oxidase positive. S. typhi only exists in humans. It can disseminate hematogenously, produces H2S, contains flagella (salmon swim). Contain endotoxin and Vi capsule. A large inoculum is required because organism is inactivated by gastric acids. Antibiotics prolong duration on fecal excretion. Immune response is primarily monocytes. Manifests as GI constipation, followed by diarrhea. There is oral vaccine contains live attenuated S typhi IM vaccine contains Vi capsular polysaccharide. Causes typhoid fever (rose spots on abdomen, constipation abdominal pain, and fever); treat with ceftriaxone or fluoroquinolone. Carrier state with gallbladder colonization.

Answer 207

Both Salmonella and Shigella are gram negative bacilli that are non lactose fermenters and oxidase positive. salmonella can exist in humans and animals. It can disseminate hematogenously, produces H2S, contains flagella (salmon swim). Contain endotoxin. A large inoculum is required because organism is inactivated by gastric acids. Antibiotics prolong duration on fecal excretion. Immune response is PMNs in disseminated disease. GI manifestation is bloody diarrhea/ There is no vaccine. Poultry, eggs, pets, and turtles are common sources. Gastroenteritis is usually caused by non-typhoidal Salmonella.

Answer 208

Both Salmonella and Shigella are gram negative bacilli that are non lactose fermenters and oxidase positive. Reserved in humans only. Spreads from cell to cell; no hematologenous spread. They do not produce H2S or contain flagella. Contain endotoxin and shiga toxin (enterotoxin). A very small inoculum is required for infection; resistant to gastric acids. Antibiotics shorten duration of fecal excretion. Immune response consists of primarily PMN infiltration. Causes bloody diarrhea (bacillary dysntery). No vaccine. Four F's: fingers, flies, food, feces are the principal factors in transmission. In order of decreasing severity (less toxin produced): S dysenteriae, S flexneri, S boydii, S sonnei. Invasion is the key to pathogenicity: organisms that produce little toxin can cause disease due to invasion.

Answer 209

Vibrio cholerae is a comma-shaped gram-negative bacillus. Produces profuse rice water diarrhea via enterotoxin that permanently activates Gs, increases cAMP. Comma shaped, oxidase positive, grows in alkaline media. Endemic to developing countries. Prompt oral rehydration is necessary.

Answer 210

Yersinia enterocolitica is a facultative anaerobic, non lactose-fermenting gram-negative coccobacillus. usually transmitted from pet feces (eg puppies), contaminated milk or pork. Causes acute diarrhea or pseudoappendicitis (right lower abdominal pain due to mesenteric adenitis and/or terminal iletis).

Answer 211

Causes gastritis and peptic ulcers (especially in the duodendal). Risk factor for gastric adenocarcinoma and MALT lymphoma. Curved gram negative rod that is catalase, oxidase, and urease positive (can use breath test or fecal antigen test for diagnosis). Creates alkaline environment. Most common initial treatment is triple therapy: proton pump inhibitor plus clarithromycin plus amoxicillin (or metronidazole if penicillin allergy).

Answer 212

Spiral shaped bacteria with axial filaments. Includes Borrelia (big size), Leptospira, and Treponema (BLT). Only Borrelia can be visualized using aniline dyes (Wright or Giemsa stain) in light microscopy due to size. Treponema is visualized by dark field microscopy. Borrelia is Big

Answer 213

Leptospira interrogans is an aerobic, motile spirochete and is described as having “ice tong” ends. found in water contaminated with animal urine, causes leptospirosis- flu like symptoms, myalgias (classically of calves), jaundice, photophobia with conjunctival suffusion (erythema without exudate). Prevalent among surfers and in tropics (ie Hawaii).

Answer 214

severe form of leptospirosis with jaundice and azotemia from liver and kidney dysfunction, fever, hemorrhage, and anemia. Caused by Leptospira interrogans.

Answer 215

spiral gram negative bacteria. Borrelia burgdorferi is a microaerophilic spirochete. causes lyme disease, which is transmitted by the Ixodes deer tick. Mice are important to tick life cycle. Borrelia can be visualized using aniline dyes (Wright or Giemsa stain) in light microscopy

Answer 216

a vector for Borrelia burgdorferi (lyme disease), Anaplasma supp., and the protozoa Babesia.

Answer 217

caused by Borrelia burgdorferi, spiral gram negative bacteria. Common in northeaster US. Initial symptoms include erythema chronicum migrans, flu like symptoms, with or without facial nerve palsy. Later symptoms include monoarthritis (large joints) and migratory polyarthritis, cardiac (AV nodal block), neurologic (meningitis, facial nerve palsy, polyneuropathy). Treatment includes doxycycline or ceftriaxone.

Answer 218

caused by spirochete Treponema pallidum, best visualized by dark field microscopy.

Answer 219

localized disease presenting with painless chancre (a painless ulcer, particularly one developing on the genitals as a result of venereal disease). If available use dark field microscopy to visualize treponemes in fluid from chancre VDRL is positive in 80%.

Answer 220

Disseminated disease with constitutional symptoms, maculopapular rash (including palms and soles), chondylomata lata (smooth, moist, painless, wart like white lesions on genitals); also confirmable with dark field microscopy. Secondary syphilis=Systemic. Latent syphilis (positive serology without symptoms) follows.

Answer 221

VDLR/RPR is nonspecific, confirm diagnosis with FTA-ABS.

Answer 222

Gummas (chronic granulomas, aortitis (vasa vasorum destruction), neurosyphilis (tabes dorsalis, general paresis), Argyll Robertson pupil (constricts with accommodation but is not reactive to light; prostitutes pupil, since it accommodates but does not react). Signs include broad based ataxia, positive Romberg sign, Charcot joint, stroke without hypertension. For neurosyphilis, test spinal fluid with VDRL and PCR.

Answer 223

Present with facial abnormalities such as rhagades (linear scars at angle of mouth) snuffles (nasal discharge), saddle nose, notched (Hutchinson) teeth., mulberry molars, short maxilla; saber shins (a sharp anterior bowing of the tibia); CN VIII deafness. to prevent, treat mother early in pregnancy, as placental transmission typically occurs after first trimester.

Answer 224

VDRL detects nonspecific antibody that reacts with beef cardiolipin. Inexpensive, widely available test for syphilis, quantitative, sensitive but not specific. False positive results can occur due to: Viral infection (mono, hepatitis), Drugs, Rheumatic fever, Lupus and Leprosy.

Answer 225

Flu like syndrome (fever, chills, headache, myalgia) after antibiotics are started; due to killed bacteria (usually spirochetes) releasing endotoxins.

Answer 226

caused by anaplasma spp., transmitted by Ixodes ticks (live on deer and mice). The microorganism is gram-negative and occurs in the red blood cells. Anaemia may be severe and result in cardiovascular changes such as an increase in heart rate. Haematuria may occur due to the lysis of red blood cells. General systemic signs such as diarrhea, anorexia and weight loss may also be present. A blood smear stained with Giemsa should be observed for identification of infected red blood cells and will allow definitive diagnosis. Treatment is doxycycline

Answer 227

caused by Bartonella spp, an facultative intracellular, pleomorphic, gram-negative bacillus, transmitted by cat scratch. BA is characterised by the proliferation of blood vessels, resulting in them forming tumour-like masses in the skin and other organs.

Answer 228

Causes Borrelia recurrentis, spiral gram negative bacteria. Transmitted by louse (recurrent due to variable surface antigens). Most people who are infected develop sickness between five and 15 days after they are bitten. The symptoms may include a sudden fever, chills, headaches, muscle or joint aches, and nausea. A rash may also occur. These symptoms usually continue for two to 9 days, then disappear. This cycle may continue for several weeks if the person is not treated.

Answer 229

Brucella spp. are small, gram-negative, nonmotile, nonspore-forming, rod-shaped (coccobacilli) bacteria. They function as facultative intracellular parasites. Transmitted by unpasteurized dairy. The symptoms are like those associated with many other febrile diseases, but with emphasis on muscular pain and sweating. The duration of the disease can vary from a few weeks to many months or even years.

Answer 230

Causes Clamydophila psittaci. Transmitted by Parrots, other birds. Diagnosis can be suspected in case of respiratory infection associated with splenomegaly and/or epistaxis.

Answer 231

caused by Coxiella burnetii. transmitted by aerosols of cattle/ sheep amniotic fluid, no arthropod vector. Presents as pneumonia. Cost common cause of culture negative endocarditis. Q fever is queer because it has no rash or vector and its causative organism can survive outside in its endospore form. Not in the Rickettsia genus, but closely related. Treatment is doxycycline

Answer 232

Caused by Ehrilichia caffeensis. Transmitted by the Lone star tick (Ambylomma). Monocytes with morulae (berry-like inclusions) in cytoplasm. The most common symptoms include headache, muscle aches, and fatigue. A rash may occur, but is uncommon. Ehrlichiosis can also blunt the immune system by suppressing production of TNF-alpha, which may lead to opportunistic infections such as candidiasis. Treatment is doxycycline

Answer 233

caused by Francisella tularensis, a rod (bacillus) gram negative zoonotic intracellular bacteria. It is also sometimes described as coccobacilus. Transmitted by ticks, rabbits, and deer fly. characterized by ulcers at the site of infection with a black base, fever, and loss of weight.

Answer 234

Leptoperia spp., transmitted but animal urine. Signs and symptoms can range from none to mild such as headaches, muscle pains, and fevers; to severe with bleeding from the lungs or meningitis

Answer 235

rod (bacillus) gram negative zoonotic bacteria. causes cellulitis and osteomyelitis. Transmitted by animal bite from cats or dogs

Answer 236

caused by Rickettsia prowazekii. Transmitted by louse. Symptoms of typhus include an incubation of 8-16 days. The onset of illness is usually relatively abrupt, usually presenting with a sudden onset of: Chills, High fever, Headache, Maculopapular rash appearing on the trunk and spreading to extremities, usually sparing the face, palms, and soles.

Answer 237

Yersinia pestis. transmitted by fleas from rats and prairie dogs.

Answer 238

a pleomorphic, gram variable rod involved in bacterial vaginosis. Presents as a gray vaginal discharge with a fishy smell; nonpainful (vs vaginitis). Associated with sexual activity, but not sexually transmitted. Bacterial vaginosis is also characterized by overgrowth of certain anaerobic bacteria in the vagina. Clue cells, or vaginal epithelial cells covered with Gardnerella bacteria (stippled appearance along outer margins), are visible under the microscope. Amine whiff test- mixing discharge with 10% KOH enhances fishy odor.

Answer 239

doxycycline

Answer 240

Rickettsie rickettsii, vector is a tick. Despite the name, it occurs primarily in the south atlantic states, especially North Carolina. Rash typically starts at wrists and ankles and then spreads to trunk, palms, and soles. Classic triad of headache, fever, and rash (vasculitis). Palms and soles rash is seen in Coxsackievirus A infection (hand, foot, and mouth disease), Rocky Mountain spotted fever and secondary syphilis: you can drive CARS using your palms and soles. Treatment is doxycycline

Answer 241

endemic fleas, Rickettsie typhi. Epidemic human body louse- R. prowazekii. Rash starts centrally and spreads out, sparing the palms and soles. Typhus on the Trunk. Treatment is doxycycline

Answer 242

Chlamydiae cannot make their own ATP. They are obligate intracellular organisms that cause mucosal infections. 2 forms: Elementary body (small, dense) is Enfectious and Enters cell via Endocytosis; transforms into reticulate body. Refticulate body Replicates in cell by fission; Reorganizes into elementary bodies. Chlamys=cloak (intracellular). Lab diagnosis: cytoplasmic inclusions seen on Giemsa or fluorescent antibody-stained smear. The chlamydial cell wall lacks classic peptidoglycan (due to reduced muremic acid), rendering, beta-lactam antibiotics less effective.

Answer 243

causes reactive arthritis (Reiter syndrome), follicular conjunctivits, nongonococcal urethritis, and PID

Answer 244

cause atypical pneumonia, transmitted by aerosol. Treatment azithromycin (one time treatment) or doxycycline. Chlamydophila psittaci have an avian reservoir.

Answer 245

Chronic infection, cause blindness due to follicular conjunctivitis in Africa. ABC= Africa, Blindness, Chronic disease

Answer 246

Urethritis/PID, ectopic pregnancy, neonatal pneumonia (staccato cough) with eosinophilia, neonatal conjunctivitis. Neonatal disease can be acquired during passage through infected birth canal.

Answer 247

Chlamydia trachomatis types L1, L2, and L3. Small paibless ulcers on genitals, swollen, painful inguinal lymph nodes that ulcerate (buboes). Treatment with doxycycline

Answer 248

Classic cause of atypical walking pneumonia (insidious onset, headache, nonproductive cough, patchy or diffuse interstitial infiltrate). X-ray look worse than patient. High titer of cold agglutinins (IgM), which can agglutinate or lyse RBCs.Grown on Eaton agar. Treatment: macrolides, doxycycline, or fluoroquinolone (penicillin ineffective since mycoplasma have no cell wall). Not seen on Gram stain. Pleomorphic. Bacterial membrane contains sterols for stability. Mycoplasmal pneumonia is more common in patients under 30. Frequent outbreaks in military recruits and prisons.

Answer 249

Includes histoplasmosis, blastomycosis, coccidioidomycosis, paracoccidioidomycosis. All can cause pneumonia and can disseminate. Except for coccidioidomycosis, all are caused by dimorphic fungi: cold (20 degrees Celsius)=mold; heat (37 degrees Celsius)=yeast. Coccidioidomycosis is a spherule (not a yeast) in tissue. Treatment includes fluconazole or itraconzole for local infection; amphotericin B for systemic infection. Systemic mycoses can mimic TB (granuloma formation), except, unlike TB, have no person to person transmission

Answer 250

Located in Mississippi and Ohio River valleys. Causes pneumonia. Macrophage filled with Histoplasma (smaller than RBC). Histo Hides within macrophages. Bird or bat droppings.

Answer 251

States east of Mississippi River and Central America. Causes inflammatory lung disease and can disseminate to skin and bone. Forms granulomatous nodules. Broad-based budding (same size as RBC). Blasto Buds Broadly

Answer 252

Located in southwestern US, California. Causes pneumonia and meningitis; can disseminate to bone and skin. Case rate increases after earthquakes (spores in dust thrown into air and are inhaled, causing spherules in lungs). Spherule (much larger than RBC) filled with endospores. Coccidio Crowds. San Joaquin Valley fever, Desert bumps=erythema nodosum, Desert rheumatism=arthralgias.

Answer 253

Located Latin America. Budding yeast with captain's wheel formation (much larger than RBC). Paracocidio PARAsails with the captains wheel all the way to Latin America.

Answer 254

A type of cutaneous mycoses. Tinea is the clinical name given to dermatophyte (cutaneous fungal) infections. Dermatophytes include Microsporum, Trichophyton, and Epidermaphyton. Branching septate hyphae visible on KOH preparation with blue fungal stain.

Answer 255

A type of cutaneous mycoses, a dermatophyte. Occurs on scalp. Associated with lymphadenopathy, alopecia, scaling.

Answer 256

A type of cutaneous mycoses, a dermatophyte. Occurs on body. Characterized by erythematous scaling rings (ringworm) and central clearing. Can be acquired from contact with an infected cat or dog.

Answer 257

A type of cutaneous mycoses, a dermatophyte. Occurs in inguinal area. Often does not show the central clearing seen in tinea corporis.

Answer 258

A type of cutaneous mycoses, a dermatophyte. There are three varieties: interdigital (most common), moccasin distribution, vesicular type

Answer 259

A type of cutaneous mycoses, a dermatophyte. Onychomycosis, occurs on nails.

Answer 260

A type of cutaneous mycoses. caused by Malassezia spp., (Pityrosporum spp.), a yeast like fungus (not a dermatophyte despite being called tinea). Degradation of lipids produces acids that damage melanocytes and cause hypopigmented and/or pink patches. Can occur any time of year but common in summer (hot, humid weather). Spaghetti and meatballs appearance on microscopy. Treatment includes topical and/or oral antifungal medications, selenium sulfide.

Answer 261

amoxicillin

Answer 262

ceftriaxone

Answer 263

Ceftriaxone, ciprofloxacin, or rifampin

Answer 264

Penicillin G

Answer 265

erythromycin ointment

Answer 266

Benzathine penicillin G or oral penicillin V

Answer 267

Benzathine penicillin G

Answer 268

prophylaxis includes TMP-SMX for Pneumocystis pneumonia.

Answer 269

prophylaxis includes TMP-SMX for Pneumocystis pneumonia and toxoplasmosis.

Answer 270

prophylaxis includes Azithromycin or clarithromycin for Mycobacterium avium complex.

Answer 271

vancomycin, daptomycin, linezolid, tigecycline, ceftaroline

Answer 272

linezolid and streptogramins (quinupristin, dalforistin)

Answer 273

polymyxins B and E (colistin)

Answer 274

Binds ergosterol (unique to fungi); forms membrane pores that allow leakage of electrolytes. AmphoTERicin TEARs holes in the fungal membrane by forming pores.

Answer 275

Serious, systemic mycoses. Cryptococcus (amphotericin B with/without flucytosine for cryptococcal meningitis), Blastomyces, Coccidioides, Histoplasma, Candida, Mucor. Intrathecally for fungal meningitis. Supplemental K and Mg because of altered renal tubule permeability.

Answer 276

Fever/chills (shake and bake), hypotension, nephrotoxicity, arrhythmias, anemia, IV phlebitis (amphoterrible). Hydration decreases nephrotoxicity. Liposomal amphotericin decreases toxicity.

Answer 277

Same as amphotericin B. Topical use only as too toxic for systemic.

Answer 278

Swish and swallow for oral candidiasis (thrush); topical for diaper rash or vaginal candidiasis.

Answer 279

inhibits DNA and RNA biosynthesis by conversion to 5-fluorouracil by cytosine deaminase.

Answer 280

Systemic fungal infections (especially meningitis caused by Cryptococcus) in combination with amphotericin B.

Answer 281

Bone marrow suppression.

Answer 282

Clotrimazole, fluconazole, itraconazole, ketoconazole, miconazole, voriconazole

Answer 283

inhibits fungal sterol (ergosterol) synthesis by inhibiting the cytochrome P-450 enzyme that converts lanosterol to ergosterol.

Answer 284

Local and less serious systemic mycoses. Flucanzole for chronic suppression of cryptococcal meningitis in AIDS patients and candidal infections of all types. Itraconazole for Blastomyces, Coccidioides, Histoplasma. Clotrimazole and miconazole for tropical fungal infections.

Answer 285

Testosterone synthesis inhibition (gynecomastia, especially with ketoconazole), liver dysfunction (inhibits P450).

Answer 286

Inhibits fungal enzyme squalene epoxidase

Answer 287

Dermatophytoses (especially onychomycosis- fungal infection of finger or toe nails).

Answer 288

GI upset, headaches, hepatotoxicity, taste disturbance

Answer 289

Anidulafungin, caspofungin, micafungin

Answer 290

Inhibit cell wall synthesis by inhibiting synthesis of beta-glucan.

Answer 291

Invasive aspergillosis, Candida

Answer 292

GI upset, flushing (by histamine release)

Answer 293

Interferes with microtubule function, disrupts mitosis. Deposits in keratin-containing tissues (eg nails)

Answer 294

Oral treatment of superficial infections; inhibits growth of dermatophytes (tinea, ringworm)

Answer 295

Teratogenic, carcinogenic, confusion, headaches, an increase in P450 and warfarin metabolism

Answer 296

Pyrimethamine (toxoplasmosis), suramin and melarsoprol (Trypanosoma brucei), nifurtimox (T. cruzi), sodium stibogluconate (leishmaniasis)

Answer 297

Permethrin (blocks Na channels, which can cause neurotoxicity), malathion (acetylcholinesterase inhibitor), lindane (blocks GABA channels, which can cause neurotoxicity). Used to treat scabies (Sarcoptes scabiei) and lice (Pediculus and Pthirus).

Answer 298

blocks detoxification of heme into hemozoin. Heme accumulates and is toxic to plasmodia.

Answer 299

Treatment of plasmodial species other than P. falciparum (frequency of resistance in P. falciparum is too high). Resistance due to membrane pump that decreases intracellular concentration of drug. Treat P. falciparum with artemether/lumefantrine or atovaquone/proguanil. For life-threatening malaria, use quinidine in US (quinine elsewhere) or artesunate.

Answer 300

Retinopathy; pruritus (especially in dark skinned individuals)

Answer 301

Mebendazole, pyrantel pamoate, ivermectin, diethylcarbamazine, praziquantel.

Answer 302

Inhibit influenza neuraminidase leading to decrease release of progeny virus

Answer 303

Treatment and prevention of both influenza A and B

Answer 304

Guanosine analogs. Monophosphorylated by HSV/VZV thymidine kinase and not phosphorylated in uninfected cells, which means fewer adverse effects. Triphosphate formed by cellular enzymes. Preferentially inhibit viral DNA polymerase by chain termination.

Answer 305

HSV and VZV. Weak activity against EBV. No activity against CMV. Used for HSV- induced mucocutaneous and genital lesions as well as for encephalitis. Prophylaxis in immunocompromised patients. No effect on latent forms of HSV and VZV. Valacyclovir, a prodrug of acyclovir, has better oral bioavailability. For herpes zoster, use famciclovir.

Answer 306

obstructive crystalline nephropathy and acute renal failure if not adequately hydrated.

Answer 307

mutated viral thymidine kinase

Answer 308

5'-monophosphate formed by a CMV viral kinase. Guanosine analog. Triphosphate formed by cellular kinases. Preferentially inhibits viral DNA polymerase. Preferentially inhibit viral polymerase by cain termination.

Answer 309

CMV, especially in immunocompromised patients. Valganciclovir, a prodrug of ganciclovir, has better bioavailability.

Answer 310

Leukopenia, neutropenia, thrombocytopenia, renal toxicity. More toxic to host enzymes than acyclovir.

Answer 311

mutated viral kinase.

Answer 312

Viral DNA/RNA polymerase inhibitor and HIV reverse transcriptase inhibitor. Binds to pyrophosphate binding site of enzyme. Does not require activation by viral kinase. Foscarnet=pyroFOSphate analog.

Answer 313

CMV retinitis in immunocompromised patients when ganciclovir fails; acyclovir-resistanct HSV.

Answer 314

Nephrotoxicity, electrolyte abnormalities (hypo- or hypercalcemia, hypo- or hyperphosphatemia, hypokalemia, hypomagnesemia) can lead to seizures.

Answer 315

mutated DNA polymerase.

Answer 316

preferentially inhibits viral DNA polymerase. Does not require phosphorylation by viral kinase.

Answer 317

CMV retinitis in immunocompromised patients; acyclovir-resistant HSV. Long half-life.

Answer 318

Nephrotoxicity (coadminister with probenecid and IV saline to decrease toxicity).

Answer 319

Highly active antiretroviral therapy (HAART): often initiated at the time of HIV diagnosis. Strongest indication for patients presenting with AIDS-defining illness, low CD+ cell counts (less than 500 cells/mm3), or high viral load. Regimen consists of 3 drugs to prevent resistance: 2 NRTIs and 1 of the following: NNRTI or protease inhibitor or integrase inhibitor.

Answer 320

Atazanavir, Darunavir, Fosamprenavir, Indinavir, Lopinavir, Ritonavir, Saquinavir

Answer 321

Assembly of virions depends on HIV-1 protease (pol gene), which cleaves the polypeptide products of HIV mRNA into their functional parts. Thus, protease inhibitors prevent maturation of new viruses. Ritonavir can boost other drug concentrations by inhibiting P450. All protease inhibitors end in -navir. Navir (never) tease a protease.

Answer 322

Hyperglycemia, GI intolerance (nausea, diarrhea), lipodystrophy. Nephropathy, hematuria (indinavir). Rifampin (a potent CYP/UGT inducer) contraindicated with protease inhibitor concentration.

Answer 323

Abacavir, Didanosine, Emtricitabine, Lamivudine, Stavudine, Tenofovir, Zidovudine

Answer 324

Competitively inhibit nucleotide binding to reverse transcriptase and terminate the DNA chain (lack a 3' OH group). Tenofovir is a nucleoTide; the others are nucleosides and need to be phosphorylated to be active. Zidovudine is used for general prophylaxis and during pregnancy to decrease the risk of fetal transmission.

Answer 325

Bone marrow suppression (can be reversed with granulocyte colony-stimulating factor [G-CSF] and erythropoietin), peripheral neuropathy, lactic acidosis (nucleosides), anemia (zidovudine), pancreatitis (didanosine).

Answer 326

Delavirdine, Efavirenz, Nevirapine

Answer 327

Bind to reverse transcriptase at site different from NRTIs. Do not require phosphorylation to be active or compete with nucleotides.

Answer 328

Rash and hepatotoxicity are common to all NNRTIs. Vivid dreams and CNS symptoms are common with efavirenz. Delavirdine and efavirenz are contraindicated in pregnancy.

Answer 329

An integrase inhibitor. Inhibits HIV genome integration into host cell chromosome by reversibly inhibiting HIV integrase.

Answer 330

increases creatine kinase.

Answer 331

includes Enfuvirtide and Maraviroc

Answer 332

Binds gp41, inhibiting viral entry

Answer 333

Skin reaction at injection sites.

Answer 334

Glycoproteins normally synthesized by virus- infected cells, exhibiting a wide range of antiviral and antitumoral properties.

Answer 335

chronic hepatitis B and C, Kaposi sarcoma, hairy cell leukemia, condyloma acuminatum, renal cell carcinoma, malignant melanoma.

Answer 336

multiple sclerosis

Answer 337

chronic gramulomatous disease

Answer 338

Neutropenia, myopathy

Answer 339

includes ribavirin, simeprevir, sofosbuvir

Answer 340

Inhibits synthesis of guanine nucleotides by competitively inhibiting inosine monophosphate dehydrogenase.

Answer 341

Chronic HCV, also used in RSV (palivizumab preferred in children).

Answer 342

hemolytic anemia; severe teratogen.

Answer 343

HCV protease inhibitor; prevents viral replication.

Answer 344

chronic HCV in combination with ribavirin and peginterferon alfa. Do not use as monotherapy

Answer 345

photosensitivity reactions, rash

Answer 346

Inhibits HCV RNA-dependent RNA polymerase acting as a chain terminator.

Answer 347

Chronic HCV in combination with ribavirin, with or without peginterferon alfa. Do not use as monotherapy.

Answer 348

Fatigue, headache, nausea.

Answer 349

Free radical oxidation. Sporicidal.

Answer 350

Halogenation of DNA, RNA, and proteins. May be sporicidal.

Answer 351

Denatures proteins and disrupts cell membranes. Not sporicidal.

Answer 352

kernicterus

Answer 353

ototoxicity

Answer 354

cartilage damage

Answer 355

embryotoxic

Answer 356

Discolored teeth, inhibition of bone growth

Answer 357

skeleton damage

Answer 358

Effects on growth and differentiation

Answer 359

gray baby syndrome

Answer 360

alba=white. Systemic or superficial fungal infection. Oral and esophageal thrush in immunocompromised (neonates, steroids, diabetes, AIDs), vulvovaginitis (diabetes, use of antibiotics), diaper rash, endocarditis in IV drug users, disseminated candidiasis (to any organ), chronic mucocutaneous candidiasis. Histologically, there are pseudohyphae and budding yeasts at 20 degrees Celsius.

Answer 361

tropical azole for vaginal; nystatin, fluconazole, orcaspofungin, or amphotericin B for systemic.

Answer 362

Invasive aspergillosis, especially in immunocompromised and those with chronic granulomatous disease. Allergic bronchopulmonary aspergillosis (ABPA) is associated with asthma and cystic fibrosis; may cause bronchiectasis and eosinophilia. Aspergillomas in lung cavities, especially after TB infection. Some species produce aflatoxins, which are associated with hepatocellular carcinoma. Histologicallym septate hyphae branch at 45 degree angles and there are conidiophore with radiating chains of spores. Think A for Acute Angles in Aspergillus; not dimorphic.

Answer 363

Cryptococcal meningitis, cryptococosis. Heavily encapsulated yeast. Not dimorphic. Found in soil, pigeon droppings. Acquired through inhalation with hematogenous dissemination to meninges. Culture on Sabouraud agar. Stains with india ink and mucicarmine. Latex agglutination test detects polysaccharide capsular antigen and is more specific. Soup bubble lesions in brain. Histology shows 5-10 micrometer yeast with wide capsular halos and unequal budding in india ink stain.

Answer 364

Mucormycosis. Disease mostly in ketoacidotic diabetic and/ or neutropenic patients (eg leukemia). Fungi proliferate in blood vessel walls, penetrate cribriform plate, and enter brain. Rhinocerebral, frontal lobe abscess; cavernous sinus thrombosis. Headache, facial pain, black necrotic eschar on face; may have cranial nerve involvement. Treatment includes surgical debridement and amphotericin B. Histology shows irregular, broad, nonseptate hypae branching at wide angles.

Answer 365

Causes Pneumocystic pneumonia (PCP), a diffuse interstitial pnuemonia. Yeast like fungus (originally classified as protozoan). Inhaled. Most infections are asymptomatic. Immunosuppression (eg AIDS) predisposes to disease. Diffuse, bilateral ground-glass opacities on CXR/CT. Diagnosed by lung biopsy or lavage. Disc shaped yeast forms on methenamine silver stain of lung tissue.

Answer 366

TMP-SMX, pentamidine, dapsone (prophylaxis only), atovaquone (prophylaxis only). Start prophylaxis when CD4+ count drops below 200 cells/mm3 in HIV patients.

Answer 367

Sporotrichosis. Dimorphic, cigar shaped budding yeast that lives on vegetation. When spores are traumatically introduced into the skin, typically by a thorn (rose gardeners disease), causes local pustule or ulcer with nodules along draining lymphatics (ascending lymphangitis). Disseminated disease possible in immunocompromised host. Treatment includes itraconazole or potassium iodide. Plant a rose in the pot.

Answer 368

Caused by giardia lamblia, a protozoa that infects the GI. Causes bloating, flatulence, foul-smelling, fatty diarrhea (often seen campers/hikers)-- fat- rich Ghiradelli chocolates for fatty stools of Giardia. Transmitted by cysts in water. Diagnosis is based on trophozoites or cysts in stool. Treatment involves metronidazole.

Answer 369

Caused by Entamoeba histolytica, a protozoa that infects the GI. Causes bloody diarrhea (dysentery), liver abscess (anchovy paste exudate), RUG pain; histology shows flask-shaped ulcer. Transmission occurs through cysts in water. Diagnosis in based on serology and/or trophozoites (with RBCs in the cytoplasm) or cysts (with up to 4 nuclei) in stool. Treatment includes metronidazole; iodoquinol for asymptomatic cyst passers.

Answer 370

A protozoa that infects the GI. Causes severe diarrhea in AIDS. Mild disease (watery diarrhea) in immunocompetent hosts. Transmitted by oocysts in water. Diagnosis is based on oocysts seen on acid-fast stain. Treatment includes prevention (by filtering city water supplies) and nitazoxanide in immunocompetent hosts.

Answer 371

A protozoa that infects the CNS. Causes congenital toxoplasmosis, which has the classic triad of chorioretinitis, hydrocephalus, and intracranial calcifications; reactivation in AIDS, which leads to a brain abscess seen as ring-enhancing lesions on CT/MRI. Transmission occurs through cysts in meat (most common); oocysts in cat feces; crosses placenta (pregnant women should avoid cats). Diagnosis is based on serology and biopsy, which shows tachyzoite (crescent shaped). Treatment includes sulfadiazine and pyrimethamine.

Answer 372

A protozoa that infects the CNS. Causes rapidly fatal meningoencephalitis. It is transferred by swimming in freshwater lakes (think Nalgene bottle filled with fresh water containing Naegleria); enters via cribriform plate. Diagnosis is based on finding amoebas in spinal fluid. Treatment includes amphotericin B, but there has been few survivors.

Answer 373

Caused by Trypanosoma brucei, which is a protozoa that infects the CNS. Causes enlarged lymph nodes, recurring fever (due to antigenic variation), somnolence, and coma. The two species include Trypanosoma brucei rhadesiense and Trypanosoma brucei gambiense. Transmission occurs by tsetse flies, which causes a painful bite. Diagnosis is based on blood smear. Treatment includes SURamin for blood-borne disease or MELAsoprol for CNS penetration. (It's SURE is nice to go to sleep, MELAtonin helps with sleep).

Answer 374

Caused by Plasmodium (P. vivax/ ovale, P. falciparum, P. malariae), a protozoa that infects the CNS. Causes fever, headache, anemia, and splenomegaly. Transmitted by Anopheles mosquito. Diagnosis is made based on blood smear, which shows trophozoite ring form within RBC, schizont containing merozoites; red granules (Schuffner stippling) throughout RBC cytoplasm seen with P. vivax/ovale.

Answer 375

Causes malaria. There are red granules (Schuffner stippling) throughout RBC cytoplasm seen with P. vivax/ovale. Incubation period is a 48 hour cycle (tertian; includes fever on first day and third day, thus fevers are actually 48 hours apart); dormant form (hypnozoite) in liver.

Answer 376

Causes malaria. There are severe; irregular fever patterns; parasitized RBCs occlude capillaries in brain (cerebral malaria), Kidneys, and lungs.

Answer 377

Causes malaria. There are 72 hour cycle fevers (quatran)

Answer 378

Chloroquine (for sensitive species), which blocks Plasmodium heme polymerase. If resistant, use mefloquine or atovaquone/ proguanil. If life- threatening use intravenous quinidine or artesunate (test for G6PD deficiency). For P. vivax/ ovale add primaquine for hypnozoite (test for G6PD).

Answer 379

Caused by babesia, a hematologic protozoa. Causes fever and hemolytic anemia; predominantly in northeastern US; asplenia increases risk of severe disease. Transmission occurs through Ixodes tick (same as Borrelia burgdorferi of lyme disease; may often coinfect humans). Diagnosis is based on blood smear, which shows a ring form and Maltese cross, and PCR. Treatment includes Atovaquone and azithromycin.

Answer 380

Caused by Trypanosoma cruzi, a protozoa. Causes dilated cardiomyopathy with apical atrophy, megacolon, megaesophagus; predominantly in South America. Unilateral periorbital swelling (Romana sign) characteristic of acute stage. Transmitted by Reduviid bug (kissing bug) feces, deposited in a painless bite. Diagnosis is based on flagellated trypomastigotes on blood smear in the acute form, and nonflagellated amastigotes within cells on biopsy. Treatment includes Benznidazole or nifurtimox.

Answer 381

Caused by Leishmania donovani, a protozoa, which causes spiking fevers, hepatosplenomegaly, pancytopenia. Transmitted by the sandfly. Diagnosis is based on macrophages containing amastigotes. Treatmetn includes amphotericin B and sodium stibogluconate.

Answer 382

Caused by Trichomonas vaginalis. Causes foul-smelling, greenish discharge; itching and burning; do not confuse with Gardnerella vaginalis, a gram variable bacterium associated with bacterial vaginosis. Transmitted by sexual contact (cannot exist outside the human body because it cannot form cysts). Diagnosis is based on trophozoites (motile) on wet mount; strawberry cervix). Treatment includes metronidazole for patient and partner (prophylaxis).

Answer 383

Enterobius vermicularis. Transmitted through the fecal-oral route. Causes intestinal infection causing anal pruitus (diagnosed by seeing egg via the tape test). Treatment includes bendazoles (because worms are bendy).

Answer 384

Ascaris lumbricoides. Transmitted through the fecal- oral route; eggs are visible in feces under microscope. Causes intestinal infection with possible obstruction at ileocecal valve. Treatment includes bendazoles (because worms are bendy).

Answer 385

Transmitted through larvae is soil penetrate the skin. Causes intestinal infection causing vomiting, diarrhea, epigastric pain (may feel like peptic ulcer). Treatment includes ivermectin or bendazoles.

Answer 386

Caused by Ancylostoma deodenale and Necator americanus. Transmitted by larvae that penetrate skin. Causes intestinal infection causing anemia by sucking blood from intestinal walls. Treated with bendazoles or pyrantel pamoate.

Answer 387

Transmitted by the fecal oral route and undercooked meat (esp. pork). Causes intestinal infection; larvae enter bloodstream and encyst in striated muscle cells, leading to inflammation of muscle. Treatment includes bendazoles (because worms are bendy).

Answer 388

Caused by trichinella. Symptoms include fever, comiting, nausea, periorbital edema, myalgia. Treatment includes bendazoles (because worms are bendy).

Answer 389

Transmitted by the female blackfly bite. Causes hyperpigmented skin and river blindness (black flies, black skin nodules, black sight); allergic reaction to microfilaria possible. Treatment includes ivermectin (IVERmectin for rIVER blindness).

Answer 390

Transmitted by deer fly, horse fly, mango fly. Causes swelling in skin, worm in conjunctiva. Treatment includes diethylcarbamazine.

Answer 391

Caused by Wuchereria bancrofti. Transmitted by female mosquito. Causes worms block lymphatic vessels, takes 9 months to a year after the bite to become symptomatic. Treatment includes diethylcarbamazine.

Answer 392

Transmitted through the fecal oral route. Causes visceral larva migrans. Treatment includes bendazoles.

Answer 393

A tapeworm. Can cause intestinal infection; transmitted through ingestion of larvae encysted in undercooked pork; treated with praziquantel. Also causes cysticercosis and neurocysticercosis; transmitted through ingestion of eggs; treat with praziquantel and albendazole (neurocysticercosis).

Answer 394

Transmitted through ingestion of larvae from raw freshwater fish. Causes vitamin B12 deficiency (tapeworm competes for B12 in intestine) leading to megaloblastic anemia. Treated with praziquantel.

Answer 395

Transmitted through ingestion of eggs from dog feces. Sheep are an intermediate host. Causes hydatid cysts in liver, causing anaphylaxis if antigens released (hydatid cyst injected with ethanol or hypertonic saline to kill daughter cysts before removal). Treated with albendazole.

Answer 396

Snails are host; cercariae penetrate skin of humans. Causes liver and spleen enlargement (S. mansoni, egg with lateral spine), fibrosis, and inflammation. Chronic infection occurs with S. haematobium (egg with terminal spine) can lead to squamous cell carcinoma of the bladder (painless hematuria) and pulmonary hypertension. Treated with praziquantel.

Answer 397

Transmitted through undercooked fish. Causes biliary tract inflammation, which causes pigmented gallstones. It is associated with cholangiocarcinoma. Treated with praziquantel.

Answer 398

Diphyllobothrium latum

Answer 399

Schistosoma mansoni, Schistosoma japonicum

Answer 400

Enterobius

Answer 401

Trichinella spiralis

Answer 402

Ancylostoma, Necator

Answer 403

Echinococcus granulosus

Answer 404

Schistosoma haematobium

Answer 405

Taenia solium (cysticercosis)

Answer 406

Clonorchis sinensis

Answer 407

Induces humoral and cell-mediated immunity but have reverted to virulence on rare occasions. Killed/inactivated vaccine induce only humoral immunity but are stable. Includes smallpox, yellow fever, rotavirus, chickenpox, Sabin polio virus, Influenza (IntraNasal). (LIVE! one night only! see SMALL YELLOW ROTAting CHICKENS get vaccinated with Sabin and MMR! Its INcredible!) No booster needed. Dangerous to give to immunocompromised patients or their close contacts. MMR= measles, mumps, rubella; live attenuated vaccine that can be given to HIV- positive patient who do not show signs of immunodeficiency.

Answer 408

Includes Rabies, Influenza (infected), Salk Polio, and HAV vaccines. (salK=Killed, RIP Always)

Answer 409

HBV (antigens-HBsAg), HPV (types 6, 11, 16, and 18)

Answer 410

All DNA viruses except the Parcoviridae are dsDNA. (All are dsDNA, like our cells, except part-of-a-virus, parvovirus is ssDNA.) Parvus=small. All are linear except papilloma-, polyoma-, hepadnaviruses (circular).

Answer 411

All RNA, except Reoviridae, are ssRNA. (All are ssRNA, except REpeatO-virus, REOvirus, is dsRNA). Positive stranded RNA viruses: I went to a RETRO (retrovirus) TOGA (togavirus) party where I drank FLAVored (flavivirus) CORONA (coronavirus) and are HIPPY (hepevirus) CALIfornia (calicivirus) PICkles (picornavirus).

Answer 412

Infectious viruses includes purified nucleic acids of most dsDNA (except for poxvirus and HBV) and all positive ssRNA (mRNA). The naked strand of negative ssRNA and dsRNA are not infectious, since they require polymerases contained within the complete virion.

Answer 413

They all replicate in the nucleus, except for poxvirus.

Answer 414

All RNA viruses replicate in the cytoplasm, except for influenza and retroviruses.

Answer 415

Naked viruses include papillomavirus, adenovirus, parvovirus, polyomavirus, calicivirus, picornavirus, reovirus and hepevirus

Answer 416

Generally, viruses acquire their envelopes from the plasma membrane when the exit from the cell. An exception to this are the herpesvirus, which acquire envelopes from nuclear membrane.

Answer 417

Includes hepadna, herpes, adeno, pox, parvo, papilloma, polyoma. All are double stranded, except for parvo. All are leaners, except for papilloma and polyoma, which are circular and supercoiled and hepadna, which are circular and incomplete. All are icosahedral, except for pox, which is complex. All replicate in the nucleus, except for pox, which carries its own DNA- Dependent RNA polymerase.

Answer 418

has an envelope, and is dsDNA, linear. Includes: HSV-1, which causes oral (and some genital lesions), spontaneous temporal lobe encephalitis, keratoconjunctivitis; HSV-2, which causes genital (and some oral) lesions; VZV (HHV-3), which causes chickpox and zoster; EBV (HHV-4), which causes mononucleosis, Burkitt lymphoma, Hodgkin lymphoma, nasopharyngeal carcinoma; CMV (HHV-5), which causes infection in immunosuppressed patients (AIDS retinitis (sightomegalovirus), especially transplant recipients, and congenital defects; HHV-6, which causes roseola (exanthem subitum); HHV-7, which is a less common cause of roseola; and HHV-8, which causes Kaposi sarcoma.

Answer 419

It has an envelope and is partially dsDNA and circular. It causes HBV, leading to either chronic or acute hepatitis. It is not a retrovirus but it does have reverse transcriptase.

Answer 420

It does not have an envelope. It has linear, dsDNA. It can cause febrile pharyngitis (sore throat), acute hemorrhagic cystitis, pneumonia, and conjunctivitis (pink eye)

Answer 421

Parvovirus does not have an envelope, and has linear, ssDNA. It is the smallest DNA virus. it is known at the B19 virus and causes apastic crises in sickle cell disease, slapped cheeks rash in children (erythema infectiosum, or fifth disease). RBC destruction in fetus leads to hydrops fetalis and death. In adults, parvovirus causes pure RBC aplasia and rheumatoid arthritis-like symptoms.

Answer 422

Papillomavirus does not have an envelope and is dsDNA and is circular. Also known as HPV, it causes warts (serotypes 1,2,6,11), cervical intraepithelial neoplasia (CIN), and cervical cancer (most commonly 16 and 18)

Answer 423

Polyomavirus does not have an envelope and is a circular dsDNA virus. Included in this category is John Cunningham virus (JCV), which causes progressive multifocal leukoencephalopathy (PML) in HIV patients. BK virus is also a member of polyomavirus and target kidneys in transplant patients. JC: Junky Cerebrum; BK: Bad Kidney

Answer 424

Poxvirus has an envelope and has linear, dsDNA. It is the largest DNA virus. It causes smallpox, which has been eradicated by use of live attenuated vaccine. Eradication was achieved by the world-wide use of vaccination. Also causes cowpox (milkmaid blisters) and molluscum contagiosum, which are flesh-colored papule with central umbilication.

Answer 425

has an envelope, and is dsDNA, linear. Causes gingivostomatitis, keratoconjunctivitis, herpes labialis, temporal lobe encephalitis (most common cause of sporadic encephalitis, can present with altered mental status, seizures, and/or aphasia). Transmitted by respiratory secretions and saliva.

Answer 426

has an envelope, and is dsDNA, linear. causes herpes genitalis, neonatal herpes. It can lie latent in the sacral ganglia. It is transmitted by sexual contact, perinatally.

Answer 427

has an envelope, and is dsDNA, linear. Varicella-zoster (chickenpox, shingles), encephalitis, pneumonia. Lies latent in dorsal root or trigeminal ganglia. Most common complication of shingles is post herpatic neuralgia. Transmitted by respiratory secretions.

Answer 428

has an envelope, and is dsDNA, linear. Mononucleosis is characterized by fever, heptoslpenomegaly, pharyngitis, and lymphadenopathy (especially in posterior cervical nodes). Transmitted by respiratory secretions and saliva; also called the kissing disease since it is commonly seen in young adults and teens. Infects B cell through CD21. Atypical lymphocytes are seen on peripheral blood smear, which are not infected B cells, but rather reactive cytotoxic T cells. Detected by a positive monospot test, which have heterophile antibodies detected by agglutination of sheep or horse RBCs. It is associated with lymphoma (eg endemic Burkitt lymphoma), nasopharyngeal carcinoma.

Answer 429

has an envelope, and is dsDNA, linear. Causes congenital infection, mononucleosis (negative monospot), pneumonia, retinitis. Infected cells have characteristic "owl eye" inclusions. It can lie latent in mononuclear cells. It is transmitted congenitally and by transfusion, sexual contact, saliva, urine, and transplant.

Answer 430

has an envelope, and is dsDNA, linear. Causes roseola, which is characterized by high fevers for several days that can cause seizures, followed by a diffuse macular rash. It is transmitted by saliva.

Answer 431

Causes Kaposi sarcoma, a neoplasm of endothelial cells. It is seen in HIV/AIDs and transplant patients. Causes dark/violaceous plaques or nodules, which represent vascular proliferation. It can also affect the GI tract and lungs. It is transmitted by sexual contact.

Answer 432

Use viral cultures for skin/genitalia. CSF PCR for herpes encephalitis. Also use Tzank test. Intranuclear inclusions are also seen with HSV-1, HSV-2, and VZV.

Answer 433

a smear of an opened skin vesicle to detect multinucleated giant cells are commonly seen in HSV-1, HSV-2, VZV infections. Tzanck heavens I dont have herpes!

Answer 434

Reoviruses do not have envelopes and are linear, dsRNA, with 10-12 segments. They also have Icosahedral (double) capsid. Included in this family are Coltivirus, which is known as Colorado tick fever and Rotavirus, the number 1 cause of fatal diarrhea in children.

Answer 435

Picornavirus does not have an envelope, it is a linear, positive ssRNA with an icosahedral capsid. Includes poliovirus, which has the polio-salk (inactivated vaccine) and the Sabin (oral poliovirus) vaccines; Echovirus, which causes aseptic meningitis; Rhinovirus, which causes the common cold; Coxsackievirus, which causes aseptic meningitis, herpangina (mouth blisters, fever), hand-foot-and mouth disease, myocarditis, and pericardiditis; HAV, which causes acute viral hepatitis. PERCH. RNA is translated into 1 large polypeptide that is cleave by protease into functional viral proteins. Can cause viral (aspetic) meningitis (except rhinovirus and HAV). All are enteroviruses (fecal-oral spread) except rhinovirus. picoRNAvirus=small RNA virus.

Answer 436

Hepevirus does not have an envelope and is a linear, positive ssRNA virus with an icosahedral capsid. Causes HEV

Answer 437

Caliciviruses are not enveloped and is a linear, positive ssRNA virus with an icosahedral capsid. Included in this family is the Norovirus, which causes viral gastroenteritis.

Answer 438

Flavivirus does have an envelope and is a positive, linear, ssRNA with an icosahedral capsid. It causes HCV, yellow fever (an arbovirus), Dengue (an arbovirus), St. Louis encephalitis (an arbovirus), and west nile virus (an arbovirus).

Answer 439

Togaviruses is enveloped and is a linear, positive ssRNA and with an icosahedral capsid. Causes Rubella, Eastern equine encephalitis (an arbovirus), Western equine encephalitis (an arborvirus).

Answer 440

Retroviruses is enveloped and is a positive, linear ssRNA with two copies. HTLV has an icosahedral capsid, while HIV has a conical capsid. They all have reverse transcriptase. HTLV causes T-cell leukemia. HIV causes AIDS.

Answer 441

Coronavirus is enveloped and is a linear, positive ssRNA with a helical capsid. Causes the common cold and SARS.(Severe Acute Respiratory Syndrome)

Answer 442

Orthomyxoviruses are enveloped and has a linear, negative, ssRNA of 8 segments with a helical capsid. Includes the influenza virus

Answer 443

Paramyxoviruses are enveloped and has a linear, negative, nonsegmented ssRNA. Includes Parainfuenza, which causes croup; RSV, which causes bronchiolitis in babies (Rx is Ribavirin); Measles; and Mumps. PaRaMyxovirus. Causes disease in children. RSV causes respiratory tract infection (bronchiolitis and pneumonia) in infants. All contain surface F (fusion) protein, which causes respiratory epithelial cells to fuse and form multinucleated cells.

Answer 444

Rhabdovirus is enveloped and is a negative, linear, ssRNA with a helical capsid. It causes rabies.

Answer 445

Filoviruses are enveloped and are negative, linear, ssRNA with a helical capsid. Causes Ebola/Marburg hemorrhagic fever, which is often fatal.

Answer 446

Arenaviruses are enveloped and are negative, circular, ssRNA with a helical capsid. Included in this category is lymphocytic choriomeningitis virus (LCMV) and Lassa fever encephalitis, which is spread by rodents.

Answer 447

Bunyaviruses are enveloped and are negative, circular ssRNA with 3 segments and with a helical capsid. Types include California encephalitis (an arbovirus), Sandfly/Rift valley fevers (an arbovirus), Crimean-Congo hemorrhagic fever (an arbovirus), and Hantavirus, which causes hemorrhagic fever, and pneumonia.

Answer 448

Delta virus is a enveloped, circular, negative ssRNA with an uncertain capsid. HDV is a defective virus that requires the presence of HBV to replicate.

Answer 449

Must transcribe negative strand to make a positive strand before it is translated into protein. Virion brings its own RNA-dependent RNA polymerase. They include Arenaviruses, Bunyaviruses, Paramyxoviruses, Orthomyxovirus, filoviruses, and Rhabdoviruses (which are also helical capsid). Always Bring Polymerase Or Fail Replication.

Answer 450

All are RNA viruses. They include Bunyaviruses, Orthomyxoviruses (influenza viruses), Arenaviruses, and Reoviruses. BOAR

Answer 451

A picovirus. It is noneveloped RNA virus and causes the common cold. There are over 100 serologic types. It is also acid labile and is therefor destroyed by acid stomach and does not infect the GI like other picornaviruses. Rhino has a runny nose.

Answer 452

Yellow fever virus is a flavivirus (also an arbovirus) transmitted by Aedes mosquito. Virus has a monkey or human reservoir. Symptoms include high fever, black vomitus, and jaundice. May see councilman bodies (Liver biopsy of acute viral hepatitis typically shows panlobular lymphocytic infiltrates with ballooning hepatocytes, which are indicative of hepatocyte necrosis and hepatocyte apoptosis. Eosinophilic apoptotic globules. They are indicative viral hepatitis (acute), yellow fever, or other viral syndromes.)

Answer 453

Rotavirus is the most important cause of infantile gastroenteritis, is a segmented dsRNA virus (a reovirus). Major cause of acute diarrhea in the US during the winter, especially in day care centers, kindergartens. Villous destruction with atrophy leads to a decrease absorption of Na and loss of K. ROTAvirus= Right Out The Anus. CDC recommends routine vaccination of all infants.

Answer 454

Orthomyxoviruses. They are enveloped, negative, ssRNA viruses with 8 segment genome, which contain hemagglutinin (promotes viral entry) and neuramindase (promotes progeny virion release) antigens. Patients with this virus are at risk for fetal bacterial superinfection, most commonly S aureus, S pneumoniae, and H. influnezae. Undergoes rapid genetic changes. The reformulated vaccine (the flue shot) contains viral strains most likely to appear during the flu season. Killed viral vaccines are the most common. Live attenuated vaccine contains temperature-sensitive mutant that replicates in the nose but not in the lung; administered intranasally.

Answer 455

Causes pandemics. Reassortment of viral genome segments, such as when segments of human flu A virus reassort with swine flu A virus. Sudden Shift is more deadly than graDual Drift.

Answer 456

Causes epidemics. Minor (antigenic drift) changes based on random mutation in hemagglutinin or neuramindase genes.

Answer 457

A togavirus. Causes rubella, once known as German (3-day) measles. Fever, postauricular and other lymphadenopathy, arthralgias, and fine rash. Causes mild disease in children but serious congenital disease. Congenital rubella findings include blueberry muffin appearance, indicative of extramedullary hematopoiesis. The rash appears as a fine, confluent macules that start on the face and spread centrifugally to involve the trunk and extremities.

Answer 458

It is a monoclonal antibody against F protein that prevents pneumonia caused by REV infection in premature infants.

Answer 459

Caused by parainfluenza viruses (paramyxovirus). Results in seal-like barking cough and inspiratory stridor. Narrowing of upper trachea and subglottis leads to characteristic steeple sign on X-ray. Severe croup can result in pulsus paradoxus (an abnormally large decrease in systolic blood pressure and pulse wave amplitude during inspiration) secondary to upper airway obstruction.

Answer 460

A paramyxovirus that causes measles. Usual presentation involves prodromal fever with cough, coryza (Irritation and swelling of the mucous membrane in the nose), and conjunctivitis, then eventually Koplik spots (bright red spots with blue- white center on buccal mucosa that precede the measles rash by 1-2 days), followed by a maculopapular rash (confluent erythematous macules and papules, presents late, and includes limbs as it spreads downwards) that starts at the head/ neck and spreads downward. Lymphadenitis with Warthin-Finkeldey giant cells (fused lymphocytes) in a background of paracortical hyperplasia. SSPE (subacute sclerosing panencephalitis, occuring years later, encephalitis (1:2000), and giant cell pneumonia (rarely in immunocompromised) are possible sequelae. The 3 C's of measles: cough, coryza, conjunctivitis. Vitamin A supplementation can reduce measles mortality in malnourished or vitamin deficient children.

Answer 461

A paramyxovirus that causes mumps, an uncommon disease due to effectiveness of MMR vaccine. Symptoms include parotitis, orchitis, and aseptic meningitis (POM). Can cause sterility (especially after puberty). Mumps makes your parotid glands and testes as big as POM-poms.

Answer 462

Bullet-shaped virus. Negri bodies (cytoplasmic inclusions in neurons infected by rabies virus) are commonly found in Purkinje cells of the cerebellum and in the hippocampus neurons. Rabies has a long incubation period (weeks to months) before symptom onset. Post exposure prophylaxis includes wound cleaning plus immunization with killed vaccine and rabies immunoglobulin. Example of passive- active immunity. The virus travels to the CNS by migrating in a retrograde fashion up the nerve axons after binding to ACh receptors. The progression of the disease is as follows: fever and malaise to agitation, photophobia, hydrophobia, and hypersalivation leading to paralysis and coma and eventually leading to death. It is most commonly transmitted from a bat, raccoon or skunk bite than from a dog bite in the US.

Answer 463

Ebola virus is a filovirus that targets endothelial cells, phagocytes, and hepatocyes. It presents as an abrupt onset of flu like symptoms, diarrhea/ vomiting, high fever, myalgia. It can progress to DIC, diffuse hemorrhage, and shock. High mortality rate and no definitive treatment. Treatment includes supportive care. Strict isolation of infected individuals and barrier practices for health care workers are key for preventing transmission. Transmission requires direct contact with bodily fluids or formites (including dead bodies); high incidence of nosocomial infection.

Answer 464

Signs and symptoms of all hepatitis viruses include episodes of fever, jaundice, elevated ALT and AST. One may see councilman bodies (eosinophilic apoptotic globules) on liver biopsy.

Answer 465

HAV is a RNA picornavirus. HAV and HEV are transmitted via the fecal oral route (the vowels hit your bowels). Naked viruses do not rely on an envelope, so they are not destroyed by the gut. There is no carrier state. Incubation period is short (weeks). There is no associated hepatocellular carcinoma risk. The disease is usually Asymptomatic, Acute, and Alone (no carriers).

Answer 466

HBV is a DNA hepadnavirus. It is transmitted parenterally, sexually, or perinatally (Blood, Baby-making, and Birthing). There is a carrier state and incubation is long (months). There is an associated risk of hepatocellular carcinoma. In HBV, the DNA polymerase has both DNA and RNA-dependent activities. Upon entry into the nucleus, the polymerase functions to complete the partial dsDNA. The host RNA polymerase transcribes mRNA from viral DNA to make viral proteins. The DNA polymerase then reverse transcribes viral RNA to DNA, which is genome of the progeny virus.

Answer 467

HCV is a RNA flavivirus. It is transmitted primarily through the blood (IVDU, post-transfusion). There is a carrier state and an associated risk of hepatocellular carcinoma. There is a long incubation period. (Chronic, Cirrhosis, Carcinoma, and Carrier)

Answer 468

HDV is a RNA delta virus. It is transmitted parenterally, sexually, or perinatally (like HBV). There is a carrier state. In order to be infective, it must either manifest as a superinfection (HDV after HBV), with a short incubation period, or a coinfection (HDV with HBV), with a long incubation period. Super-infections have a worse prognosis There is an associated risk with hepatocellular carcinoma. (Defective virus Dependent of HBV)

Answer 469

HEV is a RNA hepevirus. HAV and HEV are transmitted via the fecal oral route, especially waterborne (the vowels hit your bowels). Naked viruses do not rely on an envelope, so they are not destroyed by the gut. There is no carrier state and the incubation period is short. There is no associated risk with hepatocellular carcinoma. There is high mortality in pregnant women. (Enteric, Expectant mothers, Epidemic)

Answer 470

IgM antibody to HAV is the best test to detect acute hepatitis A

Answer 471

IgG antibody indicates prior HAV infection and/or prior vaccination; protects against reinfection.

Answer 472

Antigen found on surface of HBV; indicates hepatitis B infection.

Answer 473

Antibody to HBs-Ag; indicates immunity to hepatitis B.

Answer 474

antigen associated with core of HBV

Answer 475

Antibody to HBcAg; IgM= acute/recent infection; IgG= prior exposure or chronic infection. IgM anti-HBc may be the sole positive marker of infection during window period.

Answer 476

A second, different antigenic determinant in the HBV core. HBeAg indicates active viral replication and therefore high transmissibility.

Answer 477

antibody to HBeAg; indicates low transmissibility.

Answer 478

viral hepatitis

Answer 479

alcoholic hepatitis

Answer 480

chronic HBV with high infectivity

Answer 481

chronic HBV with low infectivity

Answer 482

recovery from HBV

Answer 483

Immunized against HBV

Answer 484

Diploid genome (2 molecules of RNA). The 3 structural genes (protein coded for): env (gp 120 and gp 41), which is formed from cleavage of gp 160 to form envelope glycoproteins; gag (p24), a capsid protein; and pol, reverse transcriptase, aspartate protease, and integrase. Reverse transcriptase synthesizes dsDNA from genomic RNA; dsDNA integrates into host genome. Virus binds CD4 as well as a coreceptor, either CCR5 on macrophages (early infection) or CXCR4 on T cells (late infection). Homozygous CCR5 mutation gives immunity to HIV. A heterozygous mutation causes a slower course.

Answer 485

the attachment of HIV to host CD4+ T cell

Answer 486

HIV uses this for fusion and entry.

Answer 487

Presumptive diagnosis made with ELISA (sensitive, high false-positive rate and low threshold, therefore it is a rule out test); positive results are then confirmed with Western blot assay (specific, low false-positive rate and high threshold, a rule in test). Viral load tests determine the amount of viral RNA in the plasma. High viral load associated with poor prognosis. Also the viral load can be used to monitor effect of drug therapy. AIDS can be diagnosed with a CD4+ is less than 200 cells/mm3. (normal is 500-1500). HIV- positive diagnoses can be made with the presence of an AIDS-defining condition (eg Pneumocystis pneumonia) or CD4+ percentage less than 14%. ELISA/Western blot tests look for antibodies to viral proteins; these tests often are falsely negative in the first 1-2 months of HIV infection and falsely positive initially in babies born to an infected mother due to anti-gp 120 crosses the placenta.

Answer 488

1. Flu-like (acute), 2. Feeling fine (latent), 3. Falling count, 4. Final crisis. During the latent phase, virus replicates in lymph nodes. As CD4+ count falls, risks of reactivation of past infections (eg TBS, HSV, shingles), dissemination of bacterial infections and fungal infections (eg coccidioidomycosis), and non Hodgkin lymphoma incidence increases.

Answer 489

Candida albicans, EBV, Bartonella henselae presents as Bacillary angiomatosis, HHV-8, Cryptosporidium spp., HPV.

Answer 490

An infection that present in HIV patients with less than 500 cells/mm3. Candida albicans presents with oral thrush and findings include scrapable white plaque, pseudohyphae on microscopy.

Answer 491

An infection that present in HIV patients with less than 500 cells/mm3. EBV presents as oral hairy leukoplakia and findings include unscrapable white plaque on lateral tongue. In patients with less than 100, B-cell lymphoma (eg non-Hodgkin lymphoma, CNS lymphoma) occurs. CNS lymphoma presents as ring enhancing, may be solitary (vs Toxoplasma).

Answer 492

An infection that present in HIV patients with less than 500 cells/mm3. Bartonella henselae, an facultative intracellular, pleomorphic, gram-negative bacillus, presents as Bacillary angiomatosis and findings includes a biopsy with neutrophilic inflammation.

Answer 493

An infection that present in HIV patients with less than 500 cells/mm3. HHV-8 presents as Kaposi sarcoma and findings include a biopsy with lymphocytic inflammation.

Answer 494

An infection that present in HIV patients with less than 500 cells/mm3. Cryptosporidium spp. presents as chronic watery diarrhea and findings include an acid-fast test showing oocysts in stool.

Answer 495

An infection that present in HIV patients with less than 500 cells/mm3. HPV presents as squamous cell carcinoma, commonly of the anus (in men who have sex with men) or cervix (in women).

Answer 496

Toxoplasma gondii, Dementia, JC virus (reactivation), Pneumoxystis jirovecii.

Answer 497

An infection that present in HIV patients with less than 200 cells/mm3. It presents as brain abscesses and findings show multiple ring-enhancing lesions on MRI.

Answer 498

An infection that present in HIV patients with less than 200 cells/mm3.

Answer 499

Occurs due to reactivation. Presents as a progressive multifocal leukoencephalopathy. Findings show non-enhancing areas of demyelination on MRI.

Answer 500

An infection that present in HIV patients with less than 200 cells/mm3. Presents as Pneumocystis pneumonia. On CXR, ground-glass opacities can be seen.

Answer 501

Aspergillus fumigatus, Cryptococcus neoformans, Candida albicans, CMV, EBV,

Answer 502

An infection that present in HIV patients with less than 100 cells/mm3. Presents with hemoptysis and pleuritic pain. Findings include cavitation or infiltrates on chest imaging.

Answer 503

An infection that present in HIV patients with less than 100 cells/mm3. Presents as meningitis. Findings include thickly encapsulated yeast on India ink stain.

Answer 504

An infection that present in HIV patients with less than 100 cells/mm3. Presents as retinitis, esophagitis, colitis, pneumonitis, and encephalitis. Findings include linear ulcers on endoscopy, cotton wool spots of fundoscopy. Biopsy reveals cells with intranuclear (owl eye) inclusion bodies.

Answer 505

An infection that present in HIV patients with less than 100 cells/mm3. Presents as fever, weight loss, fatigue, cough, dyspnea, nausea, vomiting, and diarrhea. Presents as oval yeast cells within macrophages.

Answer 506

An infection that present in HIV patients with less than 100 cells/mm3. Presents as nonspecific systemic symptoms (fever, night sweats, weight loss) or focal lymphadenitis.

Answer 507

prion disease are caused by the conversion of a normal (predominantly alpha helical) protein termed prion protein to a beta-pleated form, which is transmissible via CNS-related tissue (iatrogenic CJD) or food contaminated by bovine spongiform encephalopathy (BSE) infefected animal products (variant CJD). Resists protease degradation and facilitates the conversion of still more prions. Resistant to standard sterilizing procedures, including standard autoclaving. Accumulation of prions result in spongiform encephalopathy and dementia, ataxia, and death.

Answer 508

rapidly progressive dementia due to prion disease, typically sporadic (some familial forms)

Answer 509

acquired prion disease noted in tribal population practicing human cannibalism.

Answer 510

Staphylococcus epidermidis

Answer 511

Staphylococcus epidermidis; colonized by S. aureus

Answer 512

Viridans group streptococci

Answer 513

Streptococcus mutans

Answer 514

Bacteroides fragilis more than E coli

Answer 515

Lactobacillus, colonized by E. coli and group B strep.

Answer 516

Bacillus cereus. Food poisoning due to reheated rice? Be serious?!

Answer 517

Clostridium botulinum

Answer 518

Clostridium perfringens

Answer 519

E coli O157:H&

Answer 520

Salmonella

Answer 521

Vibrio parahaemolyticus and V. vulnificus, which can also cause wound infection from contact with contaminated water or shellfish

Answer 522

Campylobacter, growth at 42 degrees celsius.

Answer 523

Entamoeba histolytica

Answer 524

Enterohemorrhagic E. Coli O157:H7, makes shiga like toxin

Answer 525

Enterinvasive E. Coli

Answer 526

Salmonella has an animal reservoir, transmittable in poultry and eggs.

Answer 527

Shigella causes shiga toxin (human reservoir only); with a very low infectious concentration

Answer 528

Yersinia enterocolitica

Answer 529

C. difficile, Pseudomembranous colitis, occasionally bloody diarrhea

Answer 530

C. perfingens

Answer 531

Enterotoxigenic E. coli, produces heat labile (LT) and heat stable (ST) toxins.

Answer 532

Giardia, Cryptosporidium

Answer 533

V. cholerae produces rice water diarrhea; often from infected seafood.

Answer 534

Rotavirus, norovirus, adenovirus

Answer 535

Group B stretococci, E. coli

Answer 536

Mycoplasma pneumoniae, Streptococcus pneumoniae, GAS (group A strep), and RSV

Answer 537

Streptococcus pneumoniae, EBV (epstein barr virus), Staphylococcus aureus, Mycoplasma pneumoniae, Chlamydia pneumoniae

Answer 538

Streptococcus pneumoniae, Mycoplasma pneumoniae, Chlamydia pneumoniae, Haemophilus influenzae, Influenza virus

Answer 539

S. pneumoniae, Ifnleunza virus, Anaerobes, H. influenzae, Gram-negative rods

Answer 540

S. pneumoniae, Klebsiella, S. aureus

Answer 541

Anaerobes (eg Peptostreptococcus, Fusobacterium, Prevotella, Bacteroides)

Answer 542

Mycoplasma, Legionella, Chlamydia

Answer 543

Pseudomonas, S. aureus, S. pneumoniae

Answer 544

S. aures, enteric gram negative rods, fungi, viruses, P. jirovecii (with HIV)

Answer 545

S. aureus, Pseudomonas, other enteric gram negative rods

Answer 546

S. aureus, H. influenzae, S. pneumoniae.

Answer 547

group B streptococci, E coli, Listeria

Answer 548

S. pneumoniae, N. meningitidis, H. influenzae type B, Enteroviruses. Incidence of H. influenzae meningitis has decreased greatly with the introduction of the conjugate H. influenzae vaccine in last 10-15 years. Today cases are seen in unimmunized children.

Answer 549

S. pneumoniae, N. meningitidis (#1 in teens), Enteroviruses, HSV

Answer 550

S. pneumoniae, Gram negative rods, Listeria

Answer 551

Give ceftriaxone and vancomycin empirically. Add ampicillin if Listeria is suspected.

Answer 552

Enteroviruses (especially coxsackievirus), HSV-2 (HSV-1=encephalitis), HIV, west nile virus (also causes encephalitis), VZV

Answer 553

Cryptococcus spp.

Answer 554

Increase in opening pressure, increase in PMNs, increase in protiens, and a decrease in glucose.

Answer 555

Increase in opening pressure, an increase in lymphocytes, an increase proteins, and a decrease in glucose.

Answer 556

Normal or increase in opening pressure, an increase in lymphocytes, normal or an increase in protein, and normal levels of glucose.

Answer 557

Most commonly due to viridans streptococci and S aureus. If dental infections or extraction precedes abscess, oral anaerobes are commonly involved. Multiple abscesses are usually seen from bacteremia. A single lesion from contiguous sites is usually due to otitis media and mastoiditis and usually is seen in the temporal lobe and cerebellum. Sinusitis or dental lead to abscess in the frontal lobe. In AIDS patients, abscess is due to Toxoplasma reactivation.

Answer 558

Neisseria gonorrhoeae (rare), septic arthritis more common

Answer 559

Salmonella and S aureus

Answer 560

S aureus and S epidermidis

Answer 561

S aureus, Mycobacterium tuberculosis (pott disease)

Answer 562

Pasteurella multocida

Answer 563

Pseudomonas, Candida, S aureus are the most commoon

Answer 564

Elevated CRP and ESR are common but non specific. MRI is best for detecting an acute infection and detailing anatomic involvement. Radiographs are insensitive early but can be useful in chronic osteomyelitis.

Answer 565

Cystitis presents with dysuria, frequency, urgency, suprapubic pain and WBCs (but not casts) in urine. Primarily caused by ascension of microbes from urethra to bladder. In males, often seen in infants with congenital defects, vesicoureteral reflex. In the elderly, often due to an enlarged prostate. Ascension to kidney results in pyelonephritis, which presents with fever, chills, flank pain, costovertebral angle tenderness, hematuria, and WBC casts. Ten times more common is women ( shorter urethras colonized by fecal flora). Other predisposing factors include obstruction, kidney surgery, catheterization, GU malformation, diabetes and pregnancy.

Answer 566

E coli, colonies show green metallis sheen on EMB agar.

Answer 567

Satphylococcus saprophyticus

Answer 568

Klebsiella pneumoniae. 3rd leading cause of UTI. Urease positive.

Answer 569

Another cause of UTI. Some strains produce a red pigment; often nosocomial and drug resistant.

Answer 570

Another cause of UTI; often nosocomial and drug resistant.

Answer 571

Proteus mirabilis. Motility causes swarming on agar.

Answer 572

Pseudomonas aeruginosa; often nosocomial and drug resistant.

Answer 573

Leukocyte esterase is evidence of WBC activity. Nitrates are reduced by bacterial species (E coli). Urease positive tests show that there is a urease producing bug (Proteus, Klebsiella)

Answer 574

There is no inflammation within the vagina but there is a thin white discharge with a fishy odor. Lab findings show Clue cells and a pH over 4.5. Clue cells are epithelial cells of the vagina with a distinctive stippled appearance by being covered with bacteria. Treatment is metronidazole.

Answer 575

There is inflammation (strawberry cervix) and frothy, grey-green, foul smelling discharge. Lab findings show motile trichomonads and a pH greater than 4.5. Treatment is metronidazole. Must also treat sexual partners.

Answer 576

There is inflammation and a think, white, cottage cheese discharge. Lab findings show pseudohyphae and a normal pH (4-4.5). Treat with -azoles.

Answer 577

ToRCHeS infections. Microbes that may pass from mother to fetus. Transmission is transplacental in most cases or via delivery (especially HSV-2). Nonspecific signs common to many ToRCHeS infections include hepatosplenomegaly, jaundice, thrombocytopenia, and growth retardation. Other important infections include Streptococcus agalactiae (group B streptococci), E coli, and Listeria monocytogenes- all of which cause meningitis in neonates. Parvovirus B19 causes hydrops fetalis. Toxoplasma gondii, Rubella, CMV, HIV, Herpes simplex virus-2, Symphilis.

Answer 578

Congenital HIV

Answer 579

Congenital HSV-2. Mother is often asymptomatic

Answer 580

Congenital Syphilis. Mother presents with chancre (primary) and disseminated rash (secondary). These are the two stages most likely to result in a fetal infection.

Answer 581

Congenital Toxoplasma gondii. Transmitted via cat feces or ingestion of undercooked meat. Maternal manifestations is usually asymptomatic or rarely lymphadenopathy.

Answer 582

Congenital Rubella, transmitted by respiratory droplets. In the mother it manifests as a rash, lymphadenopathy, and arthritis.

Answer 583

Congenital CMV, transmitted by sexual contact, organ transplants. Maternal manifestations is usually asymptomatic or a mononucleosis like illness.

Answer 584

Hand-foot-mouth disease. Coxsackievirus type A

Answer 585

Roseola (exanthem subitum). HHV-6

Answer 586

Measles (rubeola). Measles virus

Answer 587

Erythema infectiosum (fifth disease). Parvovirus B19; can cause hydrops fetalis in pregnant women.

Answer 588

Rubella virus (German measles)

Answer 589

Scarlet fever. Streptococcus pyogens

Answer 590

Chickenpox. VZV

Answer 591

Chancroid. Haemophilus ducreyi (its so painful, you "do cry")

Answer 592

Chlamydia trachomatis (D-K)

Answer 593

Condylomata acuminata. HPV-6 and -11

Answer 594

Genital herpes, HSV-2, less commonly HSV-1

Answer 595

Gonorrhea. Neisseria gonorrhoeae

Answer 596

Lymphogranuloma venereum. C. trachomatis (L1-L3)

Answer 597

Treponema pallidum. Primary syphilis.

Answer 598

Secondary syphilis

Answer 599

Tertiary syphilis

Answer 600

Trichomonas vaginalis, Trichomoniasis

Answer 601

Most common causes include Chlamydia trachomatis (subacute, often undiagnosed), Neisseria gonorrhoeae (acute), C. trachomatis (most common bacterial STI in the US). Cervical motion tenderness (chandelier sign), purulent cervical discharge. PID may include salpingitis (inflammation of the fallopian tubes), endometritis, hydrosalpinx (a distally blocked fallopian tube filled with serous or clear fluid), and tubo-ovarian abscess. Salpingitis is a risk factor for ectopic pregnancy, infertility, chronic pelvic pain, and adhesion.

Answer 602

A sequele of PID. An infection of the liver capsule and "violin string" adhesions of peritoneum to liver. A perihepatitis from the ascending infection that results in right upper quadrant pain and tenderness and elevated liver-function tests.

Answer 603

E. coli (UTI) and S. aureus (wound infection) are the two most common causes.

Answer 604

Polymicrobial, gram-negative, often anaerobes. Often manifest as a right lower lobe infiltrate or right upper/ middle lobe (patient recumbent); purulent malodorous sputum.

Answer 605

Clostridium difficile, which manifests as watery diarrhea with leukocytosis.

Answer 606

S. aureus (including MRSA), gram-negative anaerobes. Manifests as erythema, tenderness, induration, drainage from surgical wound sites.

Answer 607

S. aureus (including MRSA), S. epidermidis (long term), Enterobacter. Manifests as erythema, induration, tenderness, drainage from access sites.

Answer 608

Late onset of P. aeruginosa, Klebsiella, Acinettobacter, S. aureus. Manifests as new infiltrate on chest xray, an increase in sputum production; and a sweet odor (Pseudomonas).

Answer 609

E. coli, Klebsiella, Proteus spp. Manifests as dysuria, leukocytosis, flank pain or costovertebral angle tenderness.

Answer 610

Legionella. Manifests as signs of pneumonia, GI symptoms (nausea and vomiting).

Answer 611

Rubella virus, the rash begins at the head and moves down with the postauricular lymphadenopathy. Measles virus, rash begins at the head and moves down; rash preceded by cough, coryza, conjunctivitis, and blue-white (Koplik) spots on buccal mucosa.

Answer 612

H. influenzae type B, showing microbe colonization in the nasopharynx.

Answer 613

H. influenzae type B (also capable of causing epiglottitis in fully immunized children). Causes fever with dysphagia, drooling, and difficulty breathing due to edematous "cherry red" epiglottis; "thumbprint sign" on xray.

Answer 614

Corynebacterium diphtheriae (elaborates toxin that causes necrosis in pharynx, cardiac, and CNS tissue). Grayish oropharyngeal exudate (pseudomembranes may obstruct airway); painful throat.

Answer 615

Encapsulated microbes, especially SHiN (S. pneumoniae is the most common followed by H. infleunzae type B, followed by N. meningitidis).

Answer 616

Actinomyces israelii

Answer 617

Catalase positive microbes, especially S. aureus.

Answer 618

Klebsiella

Answer 619

Pasteurella multocida

Answer 620

Borrelia burgdorferi (Lyme disease)

Answer 621

Mucor or Rhizopus spp.

Answer 622

HBV (from needlestick)

Answer 623

Candida albicans (systemic), Aspergillus.

Answer 624

Tropheryma whipplei (whipple disease)

Answer 625

Haemophilus influenzae (including epiglottis)

Answer 626

Pseudomonas aeruginosa

Answer 627

Coxsackie A virus, Treponema pallidum, Rickettsia rickettsii

Answer 628

Group B strep

Answer 629

Clostridium perfringens

Answer 630

First generation cephalosporin

Answer 631

First generation cephalosporin

Answer 632

Second generation cephalosporin

Answer 633

Second generation cephalosporin

Answer 634

Second generation cephalosporin

Answer 635

Second generation cephalosporin

Answer 636

Third generation cephalosporin. Neisseria gonorrhoeae coverage, excreted in bile

Answer 637

Third generation cephalosporin. Pseudomonas coverage

Answer 638

Third generation cephalosporin. Treats resistant otitis media.

Answer 639

Fourth generation cephalosporin. Pseudomonas coverage

Answer 640

Fifth generation cephalosporin. MRSA coverage