DIT VII: Micro Flashcards
Infections associated with birds (5)
Histoplasma capsulatum, Crytococcus neoformans, Chlamydophila psittaci, H5N1 influenza, West Nile virus
Dermatophytes (4)
Trichophytin, Microsporum, Epidermophytin, Malassezia furfur
Opportunistic fungal infections (4)
Candida albicans, Aspergillus, Cryptococcus neoformans, Mucor and Rhizopus spp
What is ringworm
Tinea corporis and capitis, caused by dermatophytes
What is tinea unguium
Onychomycosis, dermatophyte infection of fingernails
found in SW U.S. incl west Texas and California
Coccidioides immitis
Found in Mississippi and Ohio river basins
Histoplama capsulatum
Causes San Joaquin Valley fever
Coccidioides immitis
Found in rural Latin America
Paracoccidioides brasiliensis
Assoc w plant thorns and cutaneous injury
Sporothrix schenckii
Found in states E of Mississippi River
Blastomyces dermatitides
Found in bat and bird droppings
Histoplasma cpasulatum
Mold form contains barrel-shaped arthroconidia
Coccidioides immitis
Assoc w dust storms
Coccidioides immitis
Broad-based budding of yeast
Blastomyces dermatitides (BBB = broad-based buds)
Multiple-budding of yeast form
Paracoccidioides brasiliensis
Causes diaper rash
Candida albicans
Opportunistic mold with septate hyphae that branch at 45 degr. angle
Aspergillus fumigatus (Acute Angles = Aspergillus)
Opportunistic mold with irreg nonseptate hyphae that branch at wide angles (>90 degr)
Mucor & Rhizopus spp.
Causes thrush in immunocompromised pts. and vulvovaginitis in women
Candida albicans
Known for causing pneumonia in AIDS pts
Pneumocystis jirovecii
When to start Bactrim prophylaxis in AIDS pts?
When CD4 count <200 (against Pneumocystis jirovecii pneumonia)
Yeast known for causing meningitis in AIDS patients
Cryptococcus neoformans
Most common opportunistic infection in HIV pts
Pneumocystis jirovecii
Prophylaxis for Cryptococcus in AIDS pts
Fluconazole
Prophylaxis for PCP in AIDS pts
TMP-SMX (trimethoprim sulfa)
Treatment for Sporothrix schenckii
Oral potassium iodide / itraconazole
Treatment for oral candidiasis
Nystatin / fluconazole
Treatment for systemic candidiasis
Amphotericin B
Dx test for systemic candidiasis
Germ tubes in standard blood cultures
Dx test for Cryptococcus neoformans
India ink to stain capsule. Can also use tests for Crypto antigen or latex agglutination test
Dx test for Pneumocystis jirovecii
Silver stain
PCP pneumonia: type and CXR appearance
Diffuse interstitial pneumonia (atypical), ground glass appearance
What is associated with fungus ball in the lungs
Aspergilloma (Aspergillus fumigatus)
Features of infection with Mucor and Rhizopus spp.
Large necrotic lesions (black eschar), cranial nerve involvement
Organism associated with tinea versicolor
Malassezia furfur
Clinical features of tinea versicolor
Hyper/hypopigmented areas on prox limbs and trunk, large macules may coalesce, not usually pruritic
Tx for tinea versicolor
topical azole / selenium sulfide (Selsun blue)
Dx test for tinea versicolor
KOH prep of skin scraping –> spaghetti and meatball appearance
Granulomas: systemic mycoses vs TB
System mycoses = non-caseating granulomas
TB = caseating granulomas
Dx test for systemic mycoses
Sabouraud agar
Histoplasma capsulatum: size, where it resides
smaller than RBCs, Histo Hides in macrophages
Paracoccidioides brasiliensis: size, histological appearance
Much larger than RBC, captain’s wheel formation
Clinical features of Sporothrix schenckii infection
Introduced via trauma to skin, pustule / ulcer at infection site, nodules along lymphatics
MOA of penicillin (3)
- bind to penicillin-binding proteins
- inhibit formation of cross-linkages between peptidoglycans
- upregulate autolysins
Is penicillin bactericidal or bacteriostatic?
bactericidal
Forms of penicillin
Penicillin G = IV
Penicillin V = oral
Uses of penicillin
Gram + (eg strep pneumo, strep pyogenes, Actinomyces, GBS), spirochetes (eg syphilis), Gram + rods (Clostridium, Listeria, bacillus), Gram - cocci (Neisseria)
ADRs of penicillin
H.S. rxns, hemolytic anemia, thrombocytopenia
Penicillinase: what does it do, where is it produced
hydrolyses beta-lactam ring of penicillins, a lot of Gram - organisms produce in periplasm (coded by plasmids)
2 mechanisms of resistance against penicillins
- penicillinase (beta-lactamase)
2. alteration of beta-lactam targets (PBPs)
Penicillinase-resistant penicillins (4)
methicillin, nafcillin, oxacillin, dicloxacillin
Aminopenicillins (2)
ampicillin, amoxicillin
ADRs of aminopenicillins
H.S. rxns, generalized rash when given for mononucleosis
Carboxypenicillins (3)
ticarcillin, carbenicillin, piperacillin
Uses for carboxypenicillins
Pseudomonas, Gram - rods
Beta-lactamase inhibitors (3)
clavulanic acid, sulbactam, tazobactam
Name the group: methicillin, nafcillin, oxacillin, dicloxacillin
penicillinase-resistant penicillins
Name the group: ampicillin, amoxicillin
aminopenicillins
Name the group: ticarcillin, carbenicillin, piperacillin
carboxypenicillins
Clinical uses for ampicillin and amoxicillin
Gram + bacteria
Gram - rods (“HEELPSS”): H. influenzae, E. coli, Listeria, Proteus mirabilis, Salmonella, Shigella
“HEELPSS” organisms: what are they, what can be used against them?
Gram - rods: H. influenzae, E. coli, Listeria, Proteus mirabilis, Salmonella, Shigella
Use amoxicillin or ampicillin
What has greater bioavailability, ampicillin or amoxicillin?
amoxicillin
Penicillin used for syphilis
Penicillin G
Penicillin used for UTI
amoxicillin
Penicillin used for Pseudomonas
ticarcillin, carbenicillin, piperacillin (carboxypenicillins)
Penicillin used for neonatal infections
ampicillin (+ gentamicin)
HACEK organisms: what are they, and what are they known for?
Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, Kingella
- cause culture-negative endocarditis
Bacterial structure: gelatinous, polysaccharide coating, aids in attachment to foreign material
Glycocalyx
Quellung reaction: what does it test for, when will it be positive?
Anti-capsular serum, encapsulated organisms will appear swollen under microscope
Stain for Cryptococcus neoformans
India ink
Prokaryotic ribosomal subunits
50S + 30S = 70S
Eukaryotic ribosomal subunits
60S + 40S = 80S
What is bacterial transduction?
Phage attaches to bacterium, injects DNA
Name the species: cell wall contains mycolic acid, rich in lipids
Mycobacteria
Name the structure: forms attachment between 2 bacteria during conjugation
Pilus
Which organisms do not take Gram stain?
Gram - organisms, Mycobacteria, Mycoplasma, Treponema, Legionella pneumophila
How is Treponema visualized?
Dark field microscopy
Uses for Giemsa stain
Borrelia, Rickettsiae, Chlamydia, Plasmodium, Trypanosomes, Histoplasma
What is Periodic Scid-Schiff stain used to visualize, and what is it used to diagnose?
Stains glycogen and mucoploysaccharides, + in Whipple’s disease (Tropherymena whippelii)
What does Ziehl-Neesen stain used for?
Acid-fast organisms (eg Mycobacterium tuberculosis)
What does India ink stain for?
Cryptococcus neoformans
What does silver stain indicate?
Fungi (Pneumocystis jirovecii), Legionella
Where is endotoxin produced?
In outer membrane of Gram - organisms
What is a superantigen? Name 2 organisms producing superantigens
Exotoxin able to bind MHC II abd TCR simulataneously. Eg S. aureus and Strep pyogenes (Group A)
Hemolytic anemia + thrombocytopenia + acute renal failure
Hemolytic-uremic syndrome (HUS)
What toxin is produced by Corynebacterium diphtheria, and what is its MOA?
Diphtheria toxin: inactivates elongation factor EF-2, inhibiting protein synthesis
Pharyngitis with gray pseudomembranes, cardiac & nerve cell damage
Corynebacterium diphtheriae
What toxin is produced by Pseudomonas aeruginosa, and what is its MOA?
Exotoxin A: targets EF-2
What toxin is produced by Shigella, and what is its MOA?
Shiga toxin: cleaves host RNA at adenine base in 60S ribosomal subunit
What toxin is produced by enterohemorrhagic E. coli (EHEC), what is its serotype, and its effect?
E. coli 0157:H7 produces verocytotoxin (Shiga-like toxin): bloody diarrhea, damage to renal & endothelial cells (HUS)
What toxins are produced by enterotoxigenic E. coli (ETEC), their MOA, and their effect?
Heat labile toxin (increases cAMP) and heat stable toxin (increases cGMP): cause watery diarrhea
What is the #1 cause of traveller’s diarrhea?
Enterotoxigenic E. coli (ETEC)
What toxin is produced by Yersinia entercolitica, its MOA, and its effect?
Heat stable toxin, increases cGMP, causes abdo pain (like appendicitis)
What toxin is produced by Bordetella pertussis, and what is its MOA?
Pertussis toxin: binds and inhibits inhibitory proteins –> increases cAMP
What toxin is produced by Clostridium tetani, its MOA, and its effect?
Tetanospasmin: blocks release of GABA & glycine –> persistent musc contraction, lockjaw, spastic paralysis
What toxin is produced by Clostridium botulinum, its MOA, and its effect?
Exotoxins A-G: inhibit release of ACh, cause flaccid paralysis
What toxins are produced by Clostridium perfringens, and what is their effect?
Alpha toxin (phospholipase): gas gangrene & myonecrosis. Enterotoxin: food poisoning if cooked food left out too long (spores germinate).
What toxin is produced by Bacillus anthracis (including components)?
Anthrax toxin: edema factor (increases cAMP), lethal factor, protective antigen
What toxin is produced by Vibrio cholerae, and what is its MOA?
Choleragen (cholera toxin): stimulate adenylyl cyclase, increases cAMP, Cl- and water go into lumen
Effects of S. aureus alpha-toxin & beta toxin
Alpha: hemolysis. Beta: sphingomyelinase.
Effects of S. aureus proteins A, B, and C of gamma-toxin
A=B = hemolysin. B+C = leukocidin.
Effects of S. aureus hemolysin
Hemolysis
Effects of S. aureus Leukocidin
Destroys leukocytes
Effects of S. aureus enterotoxins A-E
Food poisoning, vomiting, diarrhea
Toxic shock syndrome: organism and toxin responsible, S&S
S. aureus TSST-1: high fever, hypotension, diffuse rash
Scalded skin syndrome: organism and toxin responsble
S. aureus epidermolytic / exfoliative toxins
Toxins secreted by Strep pyogenes (Group A Strep) and their effect
Streptolysin O: hemolysis (Oxygen labile). Streptolysin S: hemolysis (oxygen Stable). Erythrogenic / pyogenic toxins: scarlet fever.
What is the cause of scarlet fever?
Erythrogenic / pyogenic toxins of Strep pyogenes (Group A Strep)
1 blood culture contaminant
S. epidermidis
What does hemolysis test assess, and what are the possible results?
Ability to hemolyse blood agar. Beta hemolysis: complete ability, ring around colony. Alpha hemolysis: partial, green ring around colony. Gamma hemolysis: none.
Name the infection and clinical manifestation: contaminated deli meat, unpasteurized milk & cheese
Listeria, meningitis in very young and very old
Name the bacteria: large golden colonies
S. aureus
Name the bacteria: yellow granules (“sulfur granules”)
Actinomyces israelii
Name the bacteria: blue-green pigment
Pseudomonas aeruginosa
Name the bacteria: red pigment
Serratia marcescens
What kind of infection does Staph saprophyticus cause?
Common cause of UTIs (10-20% of females)
Name the bacteria: indwelling foreign device infections
S. epidermidis
Name the organism: pneumonia with rust coloured sputum
Strep pneumoniae
Name the organism: most prominent organism found in dental plaque, can erode and cause dental caries
Strep mutans (type of viridans Strep)
Name the organism and prophylaxis: enters circulation during dental procedures and causes subacute endocarditis
Strep sanguinis, amoxicillin
Cause of acute pharyngitis
Group A Strep (Strep pyogenes)
Name the organism: acute pharyngitis, cellulitis, bacteremia, pneumonia, necrotizing fasciitis
Group A Strep (Strep pyogenes)
Name the organism: acute post-streptococcal glomerulonephritis, rheumatic fever
Group A Strep (Strep pyogenes)
Name the organism: streptococcal toxic-shock syndrome, necrotizing fasciitis
Group A Strep (Strep pyogenes)
Jones criteria for rheumatic fever
Joints, Pancarditis, subcutaneous Nodules (Aschoff nodules), Erythema marginatum, Sydenham chorea
Aschoff nodules
Rheumatic fever
Minor criteria for rheumatic fever
Arthralgia, fever, raised ESR/CRP, prolonged PR interval
What diseases do Group B strep cause in infants, and what is the prophylaxis?
Pneumonia, sepsis, meningitis. Prophylactic penicillin during labour.
What diseases do Group B strep cause in pregnant women?
Asymptomatic bacteruria, UTI, post-partum endometritis, bacteremia
What diseases do Group B strep cause in nonpregnant adults?
Bacteremia, skin & soft tissue infections
Causes of neonatal sepsis (3)
GBS, E. coli, Listeria monocytogenes
What infections do enterococci cause?
Endocarditis & UTIs (esp in hospital)
Enterobacter vs Enterococcus
Enterobacter = Gram - rod. Enterococcus = Gram + coccus.
What organism causing endocarditis is also associated with colon cancer?
Strep bovis
Causes Q fever
Coxiella burnetii
Spores with “drumstick-like appearance”
Bacillus spp. & Clostridium spp.
Rx for Corynebacterium diphtheriae
Erythromycin/penicillin, vaccine, antitoxin
Large painless ulcer with centra necrosis (depressed black eschar), surrounded by edema
Cutaneous anthrax (Bacillus anthracis)
“Wool sorters’ disease”, mediastinal widening on CXR
Inhalational (pulmonary) anthrax (Bacillus anthracis)
What type of bacteria is Listeria monocytogenes?
Gram + rod, facultative intracellular
General Rx for anaerobes
Metronidazole, clindamycin
What infections can Actinomyces cause?
Cervicofacial disease (usually around mandible): inflammatory changes on skin, develop sinus tracts that drain pus and “sulfur granules”
Most common cause of of osteomyelitis
S. aureus
Pharyngitis resulting in glomerulonephritis
Strep pyogenes
Diarrhea after using antibiotics
C. difficile
Branching, filamentous Gram (+) rods with sulfur granules
Actinomyces israelii
Name the organism: pneumonia (esp in CF), otitis externa, UTIs, osteomyelitis (esp in DM), sepsis, contaminated medical equipment & catheters, burns, hot tub folliculitis
Pseudomonas aeruginosa
Rx for Pseudomonas aeruginosa
Piperacillin & ticarcillin, cefepime, ceftrazidime, imipenem, meropenem, fluoroquinolones
Name the organism: increased risk gastric adenocarcinoma & lymphoma, urease +
Helicobacter pylori
Dx for H. pylori
Urea breath test, stool antigens, serology studies
Rx for H. pylori (triple and quad therapy)
Triple: PPI + clarithromycin + amoxicillin/metronidazole.
Quad: bismuth + PPI + metronidazole + tetracycline
Urethritis, PID, STI, septic arthritis, conjunctivitis in newborns
N. gonorrhoeae
Rx for N. gonorrhoeae (1st and 2nd line)
1st line: ceftriaxone. 2nd line: azithromycin / doxycycline
Name the organism: meningitis, Waterhouse-Friderichsen syndrome, sepsis, DIC
N. meningitidis
Rx for for N. meningitidis (prophylaxis & Tx)
Prophylaxis: rifampin, ciprofloxacin, or ceftriaxone. Tx: ceftriaxone or penicillin G
Epiglottitis, otitis media, sinusitis, pneumonia
H. influenzae
Name the disease and organism: airway compromise, difficulty breathing & swallowing, drooling, “sniffing dog position”, “thumb sign”, esp ages 2-7 years
Epiglottitis, H. influenzae (worst form is Hib)
“Thumb sign” on X-ray
Edema due to epiglottitis
Dx of H. influenzae type B (Hib)
Produces IgA protease, culture on chocolate agar, need factors V & X for growth
Cultured on chocolate agar, needs factors V & X for growth
Hib
Tx and prophylaxis for Hib
Ceftriaxone (Tx), rifampin (prophylaxis)
Cause of chancroid
Haemophilus ducreyi
Cause and symptoms of Pontiac fever
Legionella pneumophila, flu-like symptoms
How to visualize, culture, and Dx Legionella pneumophila
Silver stain, charcoal yeast extract culture, needs iron and cysteine. Dx: antigen in urine
Rx for Legionella pneumophila
Erythromycin, other macrolides
Organism: Life-threatening meningitis + purpura
N. meningitidis
Organism: burn wound infection
Pseudomonas aeruginosa
Organism: septic arthritis in young, sexually active patients
N. gonorrhoeae
Dx of Shigella
Stool culture
Tx of Shigella
Supportive, fluoroquinolones (1st line), TMP-SMX or azithromycin (2nd line)
Organism: infected poultry and eggs, turtles, osteomyelitis in sickle cell, reactive arthritis. When does diarrhea begin?
Salmonella, diarrhea begins 1-3 days after
Tx for Salmonella food poisoning
Supportive for healthy adults, fluoroquinolones (1st line)
Disease and organism: “Rose spots” on abdomen
Typhoid fever (Salmonella typhi)
Bloody diarrhea after poultry/meat/unpasteurized milk, 1-2 weeks, assoc with Guillain-Barre syndrome
Campylobacter jejuni
Tx for Campylobacter jejuni
Fluoroquinolones, azithromycin
Organism and MOA: “Rice water” diarrhea
V. cholerae: heat labile toxin increases cAMP
Tx for V. cholerae
Oral rehydration
Organism & Tx: bloody diarrhea, undercooked pork & milk, household pets, mesenteric adenitis, outbreaks in daycares
Yersinia enterocolitica, supportive Tx
Lobar pneumonia in weakened immune systems, red current jelly sputum, major cause of UTIs
Klebsiella pneumoniae
Toxins produced by C. diff and MOA
Toxin A (enterotoxin): binds to brush border, causing fluid secretion and inflamm. Toxin B (cytotoxin): kills enterocytes.
Organism, risk factors, and histo appearance: pseudomembranous colitis
C. difficile, associated with antibiotic uses (clindamycin, ampicillin). Necrosis with exudates, fibrin, leukocytes, looks like membrane.
Dx of C. diff
C. diff toxin in stool
Tx of C. diff
Metronidazole, vancomycin (oral)
Cause of food poisoning and onset of diarrhea: meats, mayo, custard
S. aureus, 1-2 hours
Cause of food poisoning: reheated rice
Bacillus cereus
Cause of food poisoning: shellfish
Vibrio parahemolyticus & vulnificus
Cause of food poisoning: improperly canned foods
C. botulinum
Cause of food poisoning: reheated meat
C. perfringens
Cause of food poisoning: undercooked hamburger meat
E. coli 0157:H7
MOA and Tx for ETEC diarrhea
Heat-labile (incr cAMP) and heat stable (incr cGMP), no blood. Rx: supportive, cipro/levofloxacin, azithromycin (paeds)
Manifestations and Tx of EHEC diarrhea
Shiga-like toxin, bloddy diarrhea, can lead to HUS. Tx supportive
MOA of enteopathogenic E. coli (EPEC)
Adheres to apical surfaces, flattening villi and decr absorption –> watery diarrhea
MOA and Tx of enteroinvasive E. coli (EIEC)
Invades intestinal wall, leads to necrosis, inflamm, bloody diarrhea, and fever. Tx: fluoroquinolones, TMP-SMX, azithromycin.
Diarrhea transmitted from household pets
Yersinia enterocolitica
Most common cause of traveller’s diarrhea
Enterotoxigenic E. coli (ETEC)
Causes of food poisoning due to exotoxin (2)
S. aureus, B. cereus
What is the leukocyte esterase test used for?
Tests for esterase in urine from WBCs, indicates inflamm in urinary tract, also elevated in gonorrhea
What is the nitrite test used for?
Tests urine for presence of Enterobacteria (common cause of UTIs)
What infection do the following organisms have in common? E. coli, S. saprophyticus, Klebsiella pneumoniae, Proteus, Serratia marcescens, Enterobacter cloacae, Pseudomonas
Cause UTIs
Carry urease, cause stag horn calculi (which are made of what?)
Proteus mirabilis & vulgaris; ammonium + Mg + phosphates stones
UTI Tx for Gram - organisms
Sulfonamides + TMP, aminopenicillin, fluoroquinolones, nitrofurantoin
Name the drug by ADRs: hypersensitivity rxns, hemolysis, nephrotoxicity, kernicterus, displaces other drugs from albumin, Stevens-Johnson syndrome, photosensitivity
Sulfonamides
Drugs with photosensitivity reactions (3)
“SAT”: Sulfonamides, Amiodarone, Tetracyclines
What other drugs should eb avoided in patients with sulfa allergy? (7)
“Sulfa Pills Frequently Cause Terribly Acute Symptoms”: Sulfasalazine, Probenecid, Furosemide (loops), Celecoxic, Thiazides/TMP-SMX, Acetazolamide, Sulfonylureas
MOA of sulfonamides
Folic acid inhibitors, by competitively inhibiting dihydropterate synthetase
MOA of trimethoprim
Inhibits dihydrofolate reductase (in folic acid synth)
What drugs can cause Stevens-Johnson syndrome (SJS)?
Seizure drugs (ethosuxamide, lamotrigine, carbamazepine, phenobarbital, phenytoin), sulfa drugs, penicillins, allopurinol
MOA of fluoroquinolones, general family suffix
-floxacin; inhibits DNA gyrase (topoisomerase II)
ADRS: GI upset, damage to cartilage, tendonitis
Fluoroquinolones
MOA of metronidazole
Forms toxic free radicals, leading to DNA damage
Uses for metronidazole
“GET GAP on the metro!”: Giardia, Entamoeba, Trichomonas, Gardnerella vaginalis, Anaerobes (Clostridium, Bacterioides), H. Pylori
Function of enzyme urease, in which organism is it found?
Splits urea into NH3 and CO2, found in Proteus
Most common bacteria in a patient with struvite kidney stones
Proteus (then Staph)
Cause and transmission of Lyme disease
Borrelia burgdorferi, transmitted by Ixodes tick
Name the disease: fever, headache, fatigue, depression, erythema migrans
Stage 1 Lyme disease (days to 1 month)
Name the disease: bilateral Bell’s palsy, meningitis, peripheral neuropathies, AV nodal block, myopericarditis
Stage 2 Lyme disease (weeks to months)
Name the disease: chonic monoarthritis (esp knee), migratory polyarthritis, subacute encephalitis
Stage 3 Lyme disease (months to years)
Rx for Lyme disease
Doxycycline (early, 10-14 days), amoxicillin (kids), IV ceftriaxone (late)
Cause of Weil’s disease
Icterohemorrhagic Leptospirosis (Leptospira interrogans)
Where is Leptospira interrogans found, and what does it cause?
In water contaminated with animal urine. Leptospirosis: fever, chills, myalgia, headache, asymptomatic phase, meningitis, liver damage, jaundice, renal failure.
Name the disease: single painless chancre
Primary syphilis
Name the disease: fever, chills, malaise, maculopapular rash (trunk, extremities, palms, soles), condyloma lata, alopecia areata
Secondary syphilis
What are condyloma lata?
Wart-like lesions on moist areas (mouth, perineum), indicates secondary syphilis
Name the disease: gummas, aortitis, meningitis, hearing loss
Tertiary syphilis
Name the disease: tabes dorsalis
Tertiary syphilis
Name the disease: “tree barking” of aorta
Tertiary syphilis; due to destruction of vasa vasorum (supplies tissue of aorta)
Describe and name the disease: Argyll-Robertson pupil
Tertiary syphilis; constricts with accommodation but not reactive to light in that pupil
Describe and name the disease(s): Charcot’s joints
Tertiary syphilis, diabetic peripheral neuropathy; damage because of loss of proprioception/sensory info
Name 4 diseases causing rash on palms and soles
Kawasaki disease, Coxsackie A virus, Rocky Mountain Spotted Fever, secondary syphilis
Name the disease: saber shins, saddle nose, Hutchinson teeth, frontal bossing
Late congenital syphilis
Name the disease: snuffles
Early congenital syphilis
Dx of syphilis
VDRL, RPR, FTA-Abs, dark microscopy
Cause of syphilis
Treponema pallidum
Tx for syphilis
IV penicillin G, or doxycycline
Name 4 things that can cause a false positive VDRL
“VDRL”: Viruses (mono, EBV), Drugs, Rheumatic fever, Lupus & Leprosy
6 diseases that can cause Bell’s palsy
Lyme disease, Herpes zoster, AIDS, Sarcoidosis, Tumours, Diabetes
Disease and organism: regional LAD, basilary angiomatosis, cats
Cat scratch disease, from Bartonella
Organism: recurrent fever from variable surface antigens, from ticks and lice
Borrelia recurrentis
Disease and organism: undulent fever, from unpasteurized milk and dairy
Brucellosis, from Brucella spp.
Disease and organism: bloody diarrhea, fecal-oral from livestock, sexual
Campylobacter jejuni
Disease and organism: severe pneumonia, parrots & other birds
Psittacosis, from Chlamydophila psittaci
Disease and organism: flu-like, abrupt fever, incr perspiration, 1-2 weeks, from spores from tick feces and cattle placenta
Q fever, from Coxiella burnetii
Disease and organism: headache, muscle ache, fatigue, blunting of immune system, from lone star tick
Ehrlichiosis, from Ehrlichia chaffeensis
Disease and organism: from tick bites, rabbits, deer, can be used as biological warfare
Tularemia, from Francisella tularensis
Disease and organism: from animal urine in water, zoonotic bacteria
Leptospirosis, from Leptospira spp.
Disease and organism: can come from armadillos
Leprosy, from Mycobacterium leprae
Organism: cellulitis, osteomyelitis, bite from cat or dog
Pasteurella multocida
Cause of epidemic typhus and transmission
Rickettsia prowazekii, transmitted by louse
Cause of Rocky Mountain Spotted fever and transmission
Rickettsia rickettsii, from Dermacentor tick bite
Cause of endemic typhus and transmission
Rickettsia typhi, from fleas
Cause of bubonic plague and transmission
Yersinia pestis, from flea bites and prairie dogs
What is Pott’s disease?
TB in vertebral bodies
Ghon focus vs Ghon complex
Ghon focus: primary TB lesion in mid-lower zones of lung, can be seen on CXR when calcified. Ghon complex: Ghon focus + hilar LAD
Dx of TB
Lowenstein-Jensen agar (takes 2-4 weeks to culture), Gram +, acid fast stain of sputum (3 days in a row)
What does Mycobacterium kansasii cause, and in which patients?
Pulmonary TB-like symptoms, esp in pts with chronic bronchitis and emphysema
What is the prophylaxis for Mycobacterium avium intracellulare / MAC in AIDS, and when to start?
Azithromycin when CD4
What environments is Mycobacterium marinum associated with?
Aquatic-associated: shipyards, boat, aquarium
Tx for latent TB
6-9 months of isoniazid (INH)
Drug cocktail used in Tx of TB
“RIPE”: Rifampin + Isoniazid (INH) + Pyrazinamde + Ethambutol
What is Lowenstein-Jensen agar used for?
Dx of TB (takes 2-4 wks to culture)
What is Hansen’s disease also known as?
Leprosy
What is the causative organism in leprosy?
Mycobacterium leprae
Name the two types of leprosy and their clinical manifestations
Leprosy: infection of superficial nerves, loss of sensation in digits and feet. Lepromatous type: diffuse, failed CMI, nodules, contagious, thick plaques on dorsum of fingers and wrists. Tuberculoid type: more limited disease, hypoaesthetic nodules.
How is leprosy transmitted?
Person-to-person, armadillos
Tx for 2 types of leprosy
Lepromatous type: dapsone, rifampin, clofazimine (24 months). Tuberculoid type: dapsone + rifampin (12 months)
MOA of isonazid, ADRs, and prevention of ADRs
MOA: inhibits synth of mycolic acids. ADRs: neurotox (prevent with pyridoxine – vit B6), hepatotox, drug-induced SLE
Name the TB drug: RNA pol inhibitor, Revs up microsomal P450, Red-orange body fluids, Rapid Resistance if used alone
Rifampin
MOA of pyrazinamide and ADRs
MOA: inhibits mycolic acid synth by blocking mycobacterial pyrazinamidase, effective in acidic phagolysosomes. ADRs: hyperuricemia, hepatotox.
MOA of ethambutol and ADRs
MOA: blocks arabinosyl transferase, decreasing carbohydrate polymerization of mycobacterium cell wall. ADRs: optic neuropathy (red-green colour blindness, reversible)
Which TB drug causes reversible red-green colour blindness?
Ethambutol
Calcified granuloma in the lung, plus hilar LAD
Ghon complex
Back pain, fever, night sweats, and weight loss
Pott’s disease (TB in vertebral body)
Name the disease: Gardnerella vaginalis, Mobiluncus, Bacterioides, Mycoplasma
Bacterial vaginosis
Name the finding and disease: vaginal squamous cells covered in bacteria
Clue cells, bacterial vaginosis
Rx for bacterial vaginosis
Metronidazole (cream or oral)
What is the Rickettsial triad, and what is the general Tx?
Fever + headache + rash; doxycycline
On which coast of the US is Rocky Mountain Spotted fever found?
East
Name the types of Rickettsiae (2): rash starts centrally and spreads outward, doesn’t involve palms and soles
Rickettsia typhi (endemic typhus), Rickettsia prowazekii (epidemic typhus)
Name the disease: transmitted by tick, no rash, granulocytes with berry cluster organisms (morula)
Ehrlichiosis
Name the disease and causative organism: fever, interstitial pneumonia, spread via tick feces and cow placenta
Q fever, due to Coxiella burnetii
What does the Weil-Felix reaction test for? When will it be +/-?
Tests for Abs against Rickettsiae. + in all Rickettsial infections, - in Coxiella.
Name 3 causes of atypical pneumonia and a general Tx (if you don’t know which one it is)
Legionella penumophila, Chlamydophila pneumoniae, Mycoplasma pneumoniae; azithromycin
Rx for Chlamydophila pneumoniae
Doxycycline
Name the type of Chlamydia trachomatis: chronic infections, esp trachoma (granular conjunctivitis)
Types A, B, and C
Name the type of Chlamydia trachomatis: urethritis, PID, ectopic pregnancy, infertility, neonatal penumonia and conjunctivitis
Types D – K
Name the type of Chlamydia trachomatis: lymphogranuloma venereum (acute lymphadenitis), primary ulcer, rectal disease
Types L1, L2, L3
Dx of Chlamydiae species
Giemsa stain
Rx for Chlamydia trachomatis: general and newborns
Azithromycin, erythromycin eye drops in all newborns as prophylaxis
Which cause of pneumonia causes a high titer of cold agglutinins?
Mycoplasma pneumoniae (IgM Abs, agglutinate or lyse RBCs only in cold env’ts)
MOA of penicillins
Bind to penicillin-binding proteins, inhibit formation of cross-linkages between peptidoglycan chains
What organisms produce penicillinases, and where?
Many Gram – organisms, in periplasm
Which penicillins are resistant to penicillinase?
Methicillin, nafcillin, oxacillin
Which are the aminopenicillins, and what are their clinical uses?
Ampicillin & amoxicillin. Gram + bacteria, Gram – rods (“HEELPSS”: H. Influenzae, E. Coli, Enterococci, Listeria, Proteus, Salmonella, Shigella). Eg UTIs, colon, neonatal infections
Which antibiotics can cause a generalized rash if given for mononucleosis?
Aminopenicillins (ampicillin, amoxicillin)
Which are the carboxypenicillins and what are their clinical uses?
Ticarcillin, carbenicillin, piperacillin. Pseudomonas, Gram – rods.
Name the class: clavulanic acid, sulbactam, tazobactam
Beta-lactamase inhibitors
Which aminopenicillin has the greater oral bioavailability?
Amoxicillin > ampicillin
Penicillin used to treat syphilis
Penicillin G
Penicillin used to treat UTI
Amoxicillin
Penicillins used to treat Pseudomonas
Ticarcillin, carbenicillin, piperacillin (carboxypenicillins)
Penicillin used to treat neonatal infections
Ampicillin (+ gentamicin)
Which generation of cephalosporins have increasing Gram – coverage?
In general: incr generations have more Gram – coverage, less Gram + coverage
Which are the 1st generation cephalosporins and what are their clinical uses?
Cefalozin, cephalexin. Gram + cocci, some Gram - (“PEcK”: Proteus mirabilis, E. Coli, Klebsiella)
Which are the 2nd generation cephalosporins and what are their clinical uses?
Cefoxitin, cefaclor, cefuroxime, cefprozil. Gram + cocci, Gram - (“HENS PecK”: H. Flu, Enterobacter, Neisseria, Serratia marcescens + PEcK)
Which are the 3rd generation cephalosporins and what are their clinical uses?
Ceftriaxone, cefotaxime, ceftazidime, cefdinir. Serious Gram – infections (HENS PecK + Citrobacter), Gram – meningitis, less Gram + (Strep pneumo)
Which 3rd generation cephalosporin is excreted in bile, so is good for patients with renal failure?
Ceftriaxone
Which 3rd generation cephalosporin can also cover Pseuomonas?
Ceftazidime
Which 3rd generation cephalosporin is used to treat resistant otitis media?
Cefdinir
What is the 4th generation cephalosporin and what does it cover?
Cefepime. Broad spectrum (Gram + and –), Pseudomonas.
ADRs of cpehalosporins
H.S. Rxns (can have cross-reactivity with penicillins), nephrotox if used with aminoglycosides, disulfiram-like rxn
MOA of aztreonam
Monocyclic beta lactam, inhibits cell wall synth, binds to PBP-3, synergistic with aminoglycosides
Clinical uses for aztreonam
Gram – bacteria: PecK + Serratia, good for penicillin-allergic patients and those with renal insufficiency
Why is imipenem always used in combination with cilastatin?
Cilastatin inhibits renal dehydropeptidase 1 –> decr deactivation of imipenem in renal tubules (incr action)
Clinical uses for carbapenems
Gram + cocci, Gram – rods, anaerobes, Pseudomonas, empiric Tx of life-threatening infections
ADRs of carbapenems
GI distress, skin rash, some neurotoxicity
MOA of vancomycin
Inhibits cell wall glycopeptide poolymerization by binding to D-ala D-ala moieties of cell wall glycopeptide precursors. Not absorbed in the GI tract.
Clinical uses for vancomycin
Gram +, MRSA, Enterococci, C. Diff (oral vancomycin), Coag – Staph endocarditis, S. Epidermidis
ADRs of vancomycin
“NOT”: Nephrotox, Ototox, Thrombophlebitis, + Red Man Syndrome
What is the cause of Red Man Syndrome and how is it treated?
Vancomycin triggering non-specific mast cell degranulation. Pretreat with antihistamines, slow down infusion.
What causes vancomycin resistance?
AA change: D-ala D-ala –> D-ala D-lac
Tx for C. Diff colitis
Oral vancomycin
Inpatient Tx for MRSA
Vanocmycin
Broad spectrum coverage for appendicitis
Imipenem/cilastatin or meropenem
What are the 30S and 50S inhibitors?
“buy AT 30, CCELL at 50”. 30S: Aminoglycosides, Tetracyclines. 50S: Chloramphenicol, Clindamycin, Erythromycin (macrolides), Linomycin, Linezolid
MOA of tetracyclines
Binds 30S, prevents attachment of aminoacyl-tRNA
Which tetracycline is fecally eliminated?
Doxycycline
What inhibits absorption of tetracyclines in gut?
Milk or antacids, Fe, Ca2+, Mg2+, divalent cations
Name drug by ADRs: GI distress, discolouration of teeth in children, inhibits bone growth in children, photosensitivity, contraindicated in pregnancy
Tetracyclines
Which antibiotic can cause blue pigmentation of skin with prolonged use? (Hint: it’s a tetracycline)
Minocycline
MOA of linezolid and clinical uses
Binds 23S portion of 50S. Uses: MRSA (can be oral, as outpatient), VRE
Clinical uses for tetracyclines
“VACCUUM TH e BedRoom”: V cholerae, Acne, Chlamydia, Ureaplasma urealyticum, Mycoplasma pneumoniae, Tularemia, H pylori, Borrelia burgdorferi, Rickettsia
Clinical uses for macrolides
“PUS”: Pneumonia (esp atypical), URI (Strep pneumo and pyogenes), STD (Chlamydia, Gonorrhea)
Name the class, and how they are produced: quinupristin, dalfopristin (Synercid)
Streptogramins, synthesized by Streptomyces virginiae
MOA of streptogramins and clinical uses
Bind to 23S portion of 50S. MRSA, VRE, Staph and Strep skin infections (SERIOUS STUFF!)
Name the class by ADRs: hepatotox, pseudomembranous colitis, arthralgias, myalgias, inhibits P450
Streptogramins
Name the class: gentamicin, neomycin, amikacin, tobramycin, streptomycin
Aminoglycosides
Name the class: bactericidal, requires O2 for uptake, ineffective against anaerobes
Aminoglycosides (AminO2glycosides)
Clinical uses for aminoglycosides
Severe Gram – rod, work synergistically with beta lactams, bowel Sx and infections (neomycin)
Name the class by ADRs: Nephrotox (esp with cephalosporins), Ototox (esp with loop diuretics), Teratogenic
Aminoglycosides
Name the macrolides and their MOA
Erythromycin, azithromycin, clarithromycin. Bbind to 23S rRNA of 50S subunit
Name the class by ADRs: prolonged QT, GI discomfort, acute cholestatic hepatitis, eosinophilia
Macrolides
Drug interactions with macrolides
Incr serum conc of theophylline, incr action of oral anticoagulants (eg warfarin)
Tx for MRSA skin abscess
Oral clindamycin
MOA and clinical uses of chloramphenicol
Inhibits 50S peptidyltransferase. Meningitis (H flu, N meningitidis, Strep pneumo)
Name the class by ADRs: anemia (dose dependent), aplastic anemia (dose independent), grey baby syndrome
Chloramphenicol
What is the cause and Tx of grey baby syndrome?
Due to buildup of toxic metabolites of chloramphenicol (babies don’t have much UDP-gluconyltransferase): vomiting, ashen skin, poor musc tone, CVS collapse. Tx: stop drug, exchange transfusion, phenobarbital (induces UDP glucuronyltransferase)
MOA and clinical uses of clindamycin
Blocks peptide bond formation with 50S ribosomal subunit. Anaerobic infections, MRSA, protozoa, topically for acne, Bacterioides fragilis, C perfringens, orally for MRSA skin abscesses
ADRs of clindamycin
Pseudomembranous colitis
MOA and clinical uses of polymixins
Cationic detergents, disrupt cell memb and inactivate endotoxins. IV last resort for resistant Gram – infections, topical for many OTC antibiotic ointments (eg neosporin)
ADRs of polymixins
IV is neurotoxic and nephrotoxic (renal ATN)
What is the prophylaxis for Pneumocystis jirovecii in HIV patients, and when should it be started?
TMP-SMX, when CD4
Common causes of pneumonia in neonates and Tx
GBS, E. Coli. Ampicillin + gentamicin
Common causes of pneumonia in 4wks – 18 yrs and Tx
RSV, Mycoplasma, C. Trachomatis, C. Pneumoniae, Strep pneumo. Macrolides (azithro), ceftriaxone (for Strep pneumo)
Common causes of pneumonia in adults 18-40yrs and Tx
Strep pneumo, Mycoplasma, C pneumoniae. Azithromycin + ceftriaxone
Common causes of pneumonia in elderly and Tx
Strep pneumo, influenza, anaerobes, H flu, aspiration, Gram – rods. Multi drugs or broad spec (cefepime, carbapenems)
Common causes of hospital-acquired pneumonia and Tx
MRSA, Gram – rods. Vancomycin + gentamicin
Common causes of aspiration pneumonia and Tx
Anaerobes; clindamycin
Common causes of pneumonia in alcoholics/IV drug users
Strep pneumo, Klebsiella, Staph, anaerobes
Common causes of pneumonia in CF
Pseudomonas, S aureus, Strep pneumo
Common causes of meningitis in newborns to 6 mos
GBS, E coli, Listeria
Common causes of meningitis in 6 mos to 6 years
Enteroviruses (Echo, Coxsackie), Strep pneumo, N meningitidis (with purpura), Hib
Common causes of meningitis in 6 yrs to 60 yrs
Strep pneumo, N meningitidis, enteroviruses, HSV
Common causes of meningitis in >60 yrs
Strep pneumo, Gram – rods, Listeria
Common causes of meningitis in HIV
Cryptococcus
Tx of meningitis
Culture CSF, treat empirically (ceftriaxone, vancomycin), dexamethasone
CSF findings in bacterial meningitis
Incr pressure, incr WBCs (neutrophils), incr protein, decr glucose
CSF findings in fungal & TB meningitis
Incr pressure, incr WBCs (lymphocytes), incr protein, decr glucose
CSF findings in viral meningitis
Normal to incr P, incr WBCs (lymphocytes), normal to slightly incr protein, normal glu
Cause of osteomyelitis in diabetics and drug users
S aureus, Pseudomonas
Cause of osteomyelitis in prosthetic replacements
S aureus, S epidermidis
What are condyloma acuminata, what do you see on histology, and what is the causative organism?
Genital warts, koilocytes (squamous cells with perinuclear cytoplasmic clearing), HPV-6 & 11
What strains of HPV are associated with cervical cancer?
HPV-16 & 18
What is the chandelier sign and what does it indicate?
Cervical motion tenderness. PID, usually caused by Chlamydia trachomatis or Neisseria gonorrhoeae
What is Fitz-Hugh-Curtis syndome?
Rare complication of PID, severe infection of liver capsule
Nocosomial infections in a newborn nursery
CMV, RSV
Nocosomial infections: urinary catheterization
E. coli, Proteus, Pseudomonas, MRSA
Nocosomial infections: respiratory therapy equipment
Pseudomonas
Nocosomial infections: dialysis, needle sticks
HBV
Nocosomial infections: hyperalimentation (parenteral feeding)
Candida albicans
What is the most common TORCH infection?
CMV
Name the TORCH infection: unilateral hearing loss, seizures, chorioretinitis, hydrocephalus, intracranial calcifications
CMV
Name the TORCH infection: chorioretinitis, hydrocephalus, intracranial calcifications, cats
Toxoplasma
Name the TORCH infection: PDA, cataracts, deafness, blueberry muffin rash
Rubella
Name the TORCH infection: temporal lobe encephalitis, vesicular lesions
HSV
Name the TORCH infection: hydrops fetalis
Parvovirus B19
Two causes of low pH vaginal discharge
Physiologic discharge, Candidiasis
Two causes of high pH vaginal discharge
Trichomonas, bacterial vaginosis
Most common reportable STD
Chlamydia
Painful, indurated, ulcerated genital lesion with exudate
Chancroid
Common Tx for Trichomonas
Metronidazole
Common Tx for gonorrhea
Ceftriaxone
Common Tx for chlamydia
Doxycycline or azithromycin
Name the viral class: calicivirus, picornavirus, reovirus, hepevirus
Non-enveloped RNA viruses
Name the viral class: parvovirus, adenovirus, papillomavirus, polyomavirus
Non-enveloped DNA viruses
Where do DNA viruses replicate, and what are the exceptions?
Nucleus, except pox family (smallpox, molluscum contagiosum)
Where do RNA viruses replicate, and what are the exceptions?
Cytoplasm, except influenza and retrovirus
Which is the ssDNA virus?
Parvovirus
Which are the circular DNA viruses?
Papillomavirus, polyomavirus, hepadnavirus (partially)
Which virus has 2 copies of ssRNA (diploid)?
Retrovirus
Which are the dsRNA viruses?
Reovirus, rotavirus
Name the (+) stranded ssRNA
Retrovirus, togavirus, flavivirus, coronavirus, hepevirus, calicivirus, picornavirus
Which dsDNA viruses are not infectious when naked?
Poxvirus, hepatitis B (need protein components)
What shape are DNA virus capsids?
Icosahedral (except poxvirus)
Name the live attenuated viral vaccines (8)
Smallpox, Yellow Fever, chicken pox (varicella), MMR, Sabin polio vaccine (oral), herpes zoster, intranasal influenza, rotavirus
When are varicella and MMR vaccines contraindicated in AIDS patients?
When CD4
Name 4 killed virus vaccines
Injectable influenza, rabies, Hep A, Salk polio (injectable)
Name 2 subunit vaccines
Hep B, HPV
Name 3 egg-related vaccines
Influenza, yellow fever, MMR
Name the causative agent: cold sores, gingivostomatitis, keratoconjunctivitis, temporal lobe encephalitis, cold cores
HSV-1 (HHV-1)
What is the Tzanck smear and what does it look for?
Scrape base of open vesicle and mount on slide, look for nultinucleated giant cells. Suggests HSV-1, HSV-2, VZV
What can VZV (HHV-3) cause in adults?
Pneumonia, encephalitis
How are HSV-1, HSV-2, and VZV diagnosed?
Tzanck smear, PCR of vesicular fluid (HSV), intranuclear eosinophilic inclusions (Type A Cowdry bodies/Type 1 Cowdry inclusions)
What are Type A Cowdry bodies / Type 1 Cowdry inclusions, and what do they sggest?
Intranuclear eosinophilic inclusions; HSV & VZV
Name the disease and causative agent: 15-24 age group, infects B cells, Downey cells, fever, sore throat, posterior cervical LAD, exudative pharyngitis
Infectious mononucleosis; EBV (HHV-4)
Name the finding and disease: atypical T cells with foamy-appearing basophilic cytoplasm
Downey cells, infectious mononucleosis
What cells are infected in infectious mononucleosis?
B cells, triggering a T cell response and atypical lymphocytosis
What is a major complication of infectious mononucleosis?
Splenomegaly
What is the Monospot test, and what is it used for?
Dx of mono, detects heterophile Abs (antigens foudn in horse, sheep, and beef RBCs)
Causes of heterophile (-) mononucleosis (5)
CMV, acute HIV, toxoplasmosis, viral hepatitis, strep throat
EBV-associated malignancies (6)
Hodgkin & Burkitt lymphoma, nasopharyngeal carcinoma, diffuse large cell lymphoma, oral hairy leukoplakia, lymphoproliferative disorders
Name the causative agent: heterophile-negative mini, life threatening pneumonia in marrow transplant pts, retinitis/GI ulcerations/esophagitis in AIDS
CMV (HHV-5)
“Owl’s eye” nuclear inclusions in mononuclear and polymorphonuclear cells
CMV
Name the disease and causative agent: children, 3-5 days high fever, diffuse maculopapular rash, can cause febrile seizures
Roseola / sixth disease / exanthem subitum; HHV-6
Name the causative agent: causes highly vascular tumours, infects spindle cells from vascular and lymphatic endothelial tissue, prevalence higher in men who have sex with men
HHV-8 (Kaposi Sarcoma-associated Herpesvirus, KSHV)
What does HHV-7 cause?
May cause roseola-like infection
Tx for Kaposi sarcoma tumours
HAART, alitretinoin (topical), vinblastine (intralesional), dauno/doxorubicin
Types of Kaposi sarcoma (3)
Classic (slow growing, mets rare), epidemic (HIV/AIDS), immunocompromised (transplant patients)
MOA of acyclovir, and clinical uses
Guanosine analog, phosphorylated by viral thymidine kinase, inhibits DNA polymerase. HSV-1 & 2, VZV, EBV.
MOA and clinical uses of famciclovir
Prodrug of an acyclic guanosine nucleoside analog, relies on viral thymidine kinase. HSV-1 & 2, VZV.
MOA, clinical uses, and ADRs of ganciclovir
Activated by CMV viral kinase, inhibits viral DNA pol. Used for CMV. ADRs: bone marrow suppression, renal toxicity
MOA and clinical uses of foscarnet
Inhibits DNA pol, doesn’t require activation by thymidine kinase. Uses: resistant HSV, CMV retinitis.
What does parvovirus B19 cause in adults?
Inflammatory arthritis (looks like RA)
What is the causative agent of common warts?
HPV Types 1 & 2
What is the causative agent of 90% of genital warts?
HPV Types 6 & 11
What virus is associated with invasive cervical, vulvovaginal, anal, penile, and H&N cancers?
HPV Types 16 & 18
Name the dsDNA virus: URI followed by conjunctivitis, febrile pharyngitis, acute hemorrhagic cystitis, pneumonia, diarrhea
Adenovirus
Name the causative agent: infected cow udder, “milkmaid’s blisters”, provides immunity to smallpox
Vaccinia poxvirus (cowpox), DNA virus
Name the causative agent: umbilicated, flesh-coloured dome shaped lesions, relatively benign, usually resolves within 1 yr
Molluscum contagiosum (DNA virus)
Name the causative agent: progressive multifocal leukoencephalopathy in HIV patients
JC virus (type of Polyomavirus)
Aplastic anemia in a sickle cell patient
Parvovirus B19
Child with a fever and “slapped cheek” rash on the face that spreads to the body, lacy
Parvovirus B19 (Fifth disease)
What is the structure of reoviridae? Name two types.
Non-enveloped, icosahedral, dsRNA; rotavirus & coltivirus
Name the causative agent and structure: #1 cause of fatal diarrhea in children worldwide, outbreaks in winter months, often in daycares and playgroups
Rotavirus (nonenveloped dsRNA)
Name the disease, causative agent, and structure: mountainous regions of W. U.S. And Canada, spread by woodtick, acute and self-limited flu-like illness
Colitvirus (nonenveloped dsRNA)
Name 3 enteroviruses, the general structure, and family
Poliovirus, Coxsackivirus, Echovirus; (+)ssRNA; Picornaviridae
Name the causative agent and structure: aseptic meningitis, myocarditis, herpangina, febrile pharyngitis, hand foot mouth, myocarditis and pericarditis
Coxsackievirus; (+)ssRNA, Enterovirus, Picornaviridae
Name the causative agent and structure: infects grey matter of anterior horn of spinal cord & motor neurons of pons and medulla, paralysis
Poliovirus, (+)ssRNA (Enterovirus, Picornaviridae)
What are the two polio vaccines?
Sabin: oral, live. SalK: injected, Killed.
Name the causative agent and structure: aseptic meningitis, myocarditis, URIs, summer outbreaks, detected with PCR of CSF
Echovirus: (+)ssRNA (Enterovirus, Picornaviridae)
Name 2 causes of common cold
Rhinovirus (Picornaviridae), Coronavirus
Name the causative agent and structure: viral gastroenteritis, outbreaks on cruise ships and in nursing homes, spread via fecal-oral or vomit
Norwalk virus; (+)ssRNA (Caliciviridae)
Name the causative agent and structure: transmitted by Aedes mosquito, Sub-Saharan Africa and S. America, high fever, hemorrhagic disease, jaundice, coffee ground hematemesis, epistaxis, gum bleeding, petechiae/purpura, liver damage
Yellow Fever virus; (+)ssRNA (Flavivirus)
Name the causative agent and structure: 4 serotypes, most prevalent mosquito-borne viral disease worldwide, muscle/joint pain, headache, retro-orbital pain,
Dengue Fever, from Dengue virus; (+)ssRNA (Flavivirus)
What is the tourniquet test, and what is it used for?
Field test for Dengue hemorrhagic fever. BP cuff inflated to between SBP and DBP, leave for 5 min. Excess petechiae = incr capillary wall fragility + thrombocytopenia.
Name the causative agent and structure: fever, LAD, arthralgias, maculopapular rash, congenital defects (PDA, pulm stenosis, cataracts, deafness)
Rubella virus; (+)ssRNA (Togavirus)
From which family is the virus causing SARS?
Coronavirus
Name 4 causes of rash on palms and soles
Hand foot & mouth disease (Coxsackievirus), Meningococcus, Rocky Mountain Spotted Fever, Syphilis
Name 4 arboviruses that cause encephalitis
St. Louis encephalitis virus, Eastern equine encephalitis virus, Western equine encephalitis virus, California encephalitis virus
From which family is the Human T Cell Leukemia Virus (HTLV)?
Retrovirus (enveloped +ssRNA)
Name the causative agent and structure: bird reservoir, mosquito vector, headache, malaise, back pain, myalgia, anorexia. Severe symptoms: meningitis, encephalities, flaccid paralysis (anterior horn), AMS, death
West Nile Virus; (+)ssRNA (Flaviviridae)
Dx and Tx for West Nile Virus
Dx: serology for IgM anti-WNV Abs. Tx: supportive
What are the functions of hemagglutinin and neuraminidase?
Hemagglutinin promotes attachment of influenza virus to host cell, neuraminidase helps release progeny virus
Which are the neuraminidase inhibitors and what is their MOA?
Oseltamivir, zanamivir. Block release of viral progeny
Name the causative agent and structure: coryza, cough, conjunctivitis, Koplik’s spots, widespread maculopapular rash (starting at head and moving downward)
Rubeola virus (Measles); enveloped (-)ssRNA (Paramyxovirus)
Name the finding and causative agent: blue-grey spots on buccal mucosa, surrounded by red
Koplik’s spots, rubeola virus (measles)
Name the disease by complications: fetal loss, premature delivery, encephalitis (eg subacute sclerosing panencephalitis), giant cell pneumonia
Measles (rubeola virus)
Name the causative agent and structure: parotitis, orchitis, meningitis
Mumps virus; enveloped (-)ssRNA (Paramyxovirus)
Name the causative agent and structure: travels up peripheral nerves to CNS, Negri bodies, bullet-shaped capsids, fever, malaise, N/V, agitation, hallucinations, hydrophobia
Rabies virus; enveloped (-)ssRNA (Rhabdovirus)
Name the finding and causative agent: eosinophilic cytoplasmic inclusions, contain viral nuclear capsids (bullet-shaped)
Negri bodies; Rabies virus
3 RNA viruses spread by rodent urine
Hantavirus, Lassa fever, LCM virus
Name the causative agent: hemorrhagic fever, pulmonary syndrome (progressive pulm edema, resp failure), spread by aerosolized mouse urine
Hantavirus (RNA virus)
2 RNA viruses causing hemorrhagic fever, DIC, shock
Ebola virus, Marburg hemorrhagic fever
Name the causative agent and treatment: URI, diarrhea, fever, pancytopenia, elevated aminotransferases, bird to human spread
Avian influenza (H5N1); oseltamivir
Name the causative agent and treatment: typical flu + GI symptoms, derived from 4 strains from 3 species
Swine flu (H1N1); oseltamivir or zanamivir
Name the disease and Tx: barking seal cough, resp distress, inspiratory stridor, steeple sign on CXR, ages 6 mos to 3 years
Parainfluenza / Croup (laryngo-tracheo-bronchitis); cool mist humidifier (no proven benefit), racemic epinephrine, one dose dexamethasone, supportive, oxygen as needed
What is the steeple sign on CXR and what is it a sign of?
Due to subglottic narrowing, may indicate croup
Name the causative agent: bronchiolitis +/- pneumonia, brassy cough, wheezing, winter, fusion (F) protein allowing infected cells to bind to nearby uninfected cells
Respiratory Syncytial Virus (RSV) bronchiolitis
Tx for RSV bronchiolitis
Supplemental O2, albuterol / racemic epinephrine (not routine), ribavirin (in adults, esp if after bone marrow transplant)
MOA, uses, and ADRs of ribavirin
Guanosine analog, inhibits synth of guanine nucleotides. Uses: RSV, Hep C. ADRs: teratogen, hemolytic anemia.
Name the class and MOA: ritonavir, indinavir, nelfinavir, atazanavir
Protease inhibitors; prevents HIV-1 protease from chopping viral polypeptides into individual functional proteins
Name the HIV drug by ADRs: GI intolerance, inhibit P450, hyperlipidemia / hypertriglyceridemia, lipodystrophy, pancreatitis, nephrolithiasis, incr bilirubin
Protease inhibitors
Name the class and MOA: zidovudine, didanosine, lamivudine, abacivir, emtricitabine
Nucleoside reverse transcriptase inhibitors (NRTI); competitively inhibit HIV reverse transcriptase, must be activated by thymidine kinase
Name the class and MOA: tenofovir
Nucleotide reverse transcriptase inhibitors (NtRTI); competitively inhibit HIV reverse transcriptase, must be activated by thymidine kinase
Name the HIV drug class by ADRs: bone marrow suppression, pancreatitis, peripheral neuropathy, hepatic steatosis, hypersensitivity reaction
Nucleoside reverse transcriptase inhibitors (NRTI)
Name the class and MOA: nevirapine, delavirdine, efavirenz, etravirine, rilpivirine
Non-nucleoside reverse transciptase inhibitors (NNRTI); non-competitively inhibit reverse transcriptase, don’t need to be phosphorylated to be active
Name the HIV drug by ADRS: rash, neuropsychiatric symptoms, false-positive drug test to cannabinoids, teratogenic
NNTRIs (esp efavirenz)
MOA of enfuvirtide
HIV drug; fusion inhibitor, binds to gp41
MOA of raltegravir
HIV drug; integrase inhibitor
MOA of maraviroc
HIV drug; CCR5 antagonist (ie on macrophages), inhibits gp120 conf change so virus can’t bind host cell effectively
MOA and clinical uses of Amphotericin B
Polyene antifungal: binds ergosterol, forms pores in memb. Used for systemic fungal infections.
Name the antifungal by ADRs: fever & chills, hypotension, hypokalemia, anemia, phlebitis, arrhythmias, nephrotoxicity
Amphotericin B (“Amphoteribble”)
Name the antifungal: can be used infused intrathecally
Amphotericin B
MOA and clinical uses of nystatin
Polyene antifungal: binds ergosterol, forms pores in memb. Used for cutaneous candidiasis, oropharyngeal candidiasis. Topical only (too toxic for systemic)
MOA of azole antifungals
Inhibits P450 enzyme that converts lanosterol to ergosterol
Name the antifungal by ADRs: decr production of cortisol and testosterone (gynecomastia and impotence), drug-drug interactions (blocks P450), incr hepatic enzymes, hepatotoxicity
Azoles
MOA and clinical uses of flucytosine
Converted into 5-FU, disrupts DNA & RNA synth. Used in combo with amphotericin B for systemic candidal and crypococcal infections
MOA and clinical uses of caspofungin
Echinocandin antifungal: inhibits synth of beta-1,3D glucan, inhibiting cell wall synth. Used for ASPergillosis, candida
MOA and clinical uses of terbinafine
Inhibits fungal squalene epoxidase, inhibiting ergosterol synth. Topical for tinea pedis & cruris, oral for onychomycosis and tinea capitis. Deposited in hair, nails, and fat.
MOA and clinical uses of griseofulvin
Targets microtubule function, inhibits mitosis, deposits in keratin-containing tissue. Used for tinea corporis and capitis, onychomycosis
Name the antifungal by ADRs: may be teratogenic, headache, GI symptoms, confusion, P450 inducer
Griseofulvin
Name the causative agent and Dx test: mild and self-limiting diarrhea in normal individuals, chronic watery diarrhea in AIDS patients
Cryptosporidium; Dx by oocysts on acid fast stain of stool
Name the causative organism and Dx test: fatty, foul-smelling diarrhea, flatulence, abdo bloating, belching, hikers and campers
Giardia lamblia; Dx by pear-shaped trophozoites (double nuclei, owl’s eye appearance) or cysts in stool
Name the causative organism and Tx: pear-shaped trophozoites (double nuclei, owl’s eye appearance) or cysts in stool
Giardia lamblia; metronidazole, tinidazole
Name the causative organism and Dx: bloody diarrhea, flask-shaped ulcer, invasion of colon, liver abscess
Entamoeba histolytica; Dx via trophoziotes/cysts in stool with multiple nuclei, Abs against entamoeba, stool antigen test
Tx for Entamoeba histolytica
Metronidazole or tinidazole (for trophozoites), + iodoquinol or paromomycin (for cysts)
Most common protozoal infection in the U.S.
Trichomonas vaginalis
Dx and Tx for Trichomonas vaginalis
Wet mount of vaginal discharge shows trophozoites (pear-shaped, very motile). Metronidazole
Name the causative organism and Dx: ring enhancing lesions on MRI in HIV, congenital abnormalities (chorioretinitis + hydrocephalus + intracranial calcifications)
Toxoplasma gondii; serology (Abs) or biopsy of lesion
Tx for Toxoplasma gondii
Sulfadiazine + pyrimethamine + folinic acid
Name the causative organism and Tx: rapidly fatal meningoencephalitis, transmission from swimming in freshwater lakes, enters brain through cribiform plate
Naegleria fowleri; amphotericin B
Name the causative organism and Dx: tsetse fly, fever, LAD, somnolence, encephalitis, coma, death
Trypanosoma brucei (Africa sleeping sickness); long wispy-looking organisms on blood smear
Causative organism and Tx for African Sleeping Sickness
Trypanosoma brucei; suramin (early blood borne disease), melarsoprol (CNS involvement)
Name the causative organism and Dx: S. America, reduviid bug, dilated cardiomyopathy, megaesophagus, megacolon
Trypanosoma cruzi (Chagas disease); blood smear
Causative organism and Tx for Chagas disease
Trypanosoma cruzi; benznidazole, nifurtimox
Name the causative organism, Dx, and Tx: sand fly, spiking fevers, hepatosplenomegaly, pancytopenia
Visceral leischmaniasis (Leischmania donovani); amastigotes inside macrophages; use liposomal amphotericin B
Name the causative organism and Tx: sand fly, ulcerating papules slow to heal
Cutaneous leischmaniasis (Leischmania donovani); sodium stibogluconate
Malaria: what is the mode of transmission? Which strains have 48h and 72h cycle?
Transmitted by Anopheles mosquito. 48 h: P. Ovale and vivax. 72 h : P. Malariae
Which strains of malaria can cause dormant infection in the liver, and what is the Tx?
P. vivax and ovale; primaquine
Name the causative organism: banana-shaped gametocytes on blood smear, “diamond ring”
Plasmodium falciparum (malaria)
Tx for malaria
Chloroquine, + primquine (for P. Vivax or ovale). If chloroquine resistant: quinine + doxycycline, atovaquone-proguanil, artemesan-lumefantrine, mefloquine
Name the causative organism and Tx: Ixodes tick, ring form on blood smear, tetrad shape (Maltese cross) inside RBCs, fever, hemolytic anemia, northeastern U.S.
Babesia microti (Babesiosis); quinine + doxycycline
Most common protozoal diarrhea
Giardia lamblia
Name the causative organism, Dx, and Tx: most common helminth infection in U.S., anal pruritis
Enterobius vermicularis (pinworm); Scotch tape test; albendazole, mebendazole, or pyrantel pamoate
Name the causative organism and Tx: 2nd most common helminthic infection in U.S., bowel-lung-bowel cycle, can cause Loeffler eosinophilic pneumonitis
Ascaris lumbricoides (giant roundworm); mebendazole, albendazole, pyrantel pamoate
Name the causative organism, Dx, and Tx: undercooked meat (pork, wild game), migration from GI to muscle, myositis, fever, eosinophilia, periorbital edema
Trichinella spiralis; muscle biopsy (see larvae); use benzimidazoles
Name the causative organism and Tx: larvae live in soil and penetrate skin, travel to lungs and then GI (autoinfection), dermatitis
Strongyloides stercoralis; ivermectin, mebendazole
Name the causative organism and Tx: penetrate skin of feet, autoinfection, suck blood from wall of small intestine, abdo discomfort, anemia
Ancylostoma and Necator (hookworms); albendazole, mebendazole, pyrantel pamoate
Name 3 nematodes that enter humans orally
“EAT”: Enterobius, Ascaris, Trichinella
Name the causative organism and Tx: undercooked pork, adult infects GI, larvae infect tissues (cysticercosis), myositis, brain cysts, seizures, AMS, psych symptoms
Taenium solium; praziquantel, albendazole + dexamethasone (neurocysticercosis)
Name the causative organism and Tx: raw fish, B12 deficiency, megaloblastic anemia
Diphyllobothrium latum (fish tapeworm); praziquantel
Name the causative organism and Tx: dog feces, mature larval cysts in host parenchyma (liver and eyes), anaphylaxis
Echinococcus granulosis (dog tapeworm); Sx removal/aspiration of cysts, injection of scolicidal agent (EtOH, hypertonic saline), albendazole
Name the causative agent and Tx: mosquitoes, inflammation and obstruction of lymphatics, elephantiasis, hydrocele, lymphatic filariasis
Wuchereria bancrofti; diethylcarbamazine
Which three roundworms are transmitted through the soil?
“SANd”: Strongyloides, Ancylostoma, Necator
Name the causative organism and Tx: freshwater snail as intermediate host, swimmer’s itch, migrates to lung/liver, portal HTN and splenomegaly
Schistosoma mansoni & haematobium (blood flukes); praziquantel
Which trematode is associated with squamous cell cancer of the bladder?
Schistosoma haematobium (blood fluke)
Name the causative organism and Tx: chronic bronchitis, hemoptysis, undercooked crab meat
Paragonius westermani (lung fluke); praziquantel
Name the causative organism and Tx: undercooked fish, inflammation of biliary tract, pigmented gallstones, cholangiocarcinoma
Clonorchis sinensis (liver fluke); praziquantel, albendazole
Tx for Pediculosis capitis (head lice)
Permethrin, pyrethrin, malathion, ivermectin, spinosad, benzyl alcohol
Tx for Pediculosis pubis (pubic lice, crabs)
Permethrin, pyrethrin
Name the causative organism and Tx: severe pruritis, small papules at site of entry, webbing between fingers, linear burrows
Scabies; permethrin 5% cream, ivermectin
Name the causative organism: highly contagious, widespread keratotic crusted lesions in immunocompromised patients
Norwegian scabies
Name the helminth: adult patient from Mexico with new onset seizures and brain calcifications
Taenium solium
Why is lindane not the preferred agent in the treatment of lice?
Neurotoxicity