Microbiology Flashcards
Induces TNF and IL-1
Lipoteichoic acid (Gram +), Lipid A (portion of LPS in Gram -)
Where do Beta-lactamases live?
Periplasm
Site of endotoxin?
Outer membrane
Which bacteria have unusual cell membranes/wall?
Mycoplasma - sterols and NO cell wall; Mycobacteria - mycolic acid (long branched sat FA’s) (INH i.e. pyrodixine-like -| saturation!)
Bugs that do not Gram Stain well?
These Microbes May Lack Real Color - Tropenema, Mycobacteria, Mycoplasma, Legionella pneumophilia, Rickettsia, Chlamydia
Giemsa stain?
Certain Bugs Really Try My Patience - Chlamydia, Borrelia, Rickettsieae, Trypanosomes, Mycoplasma, Plasmodium
PAS stain?
Tropheryma whippelii; Stains glycogen
Ziel-Neelsen?
Acid-fast (Nocardia, Mycobacterium)
India Ink?
Cryptococus neoformans; India is Cryptic
Silver stain?
Fungi, Legionella, H. pylori; a Silver Pyle of Legions are Fun(gating)
Exotoxins that inhibit protein synthesis?
DAEF (Diptheria, Exotoxin A, EF): Diptheria toxin - EF-2, Exotoxin A (pseudomonas) - EF-2; Shiga toxin (ST) & Shiga-like toxin (SLT) act on 60S;
Exotoxins that increase fluid secretion?
Heat-labile toxin (LT), heat-stable toxin (ST) [ETEC], Edema factor (bacillus), cholera toxin. Fluids - Back ETtack Cholera.
Exotoxins that inhibit phagocytic ability?
Pertussis toxin - stimulates adenylate cyclase by disabling Gi.
Exotoxins that inhibit release of neurotransmitter?
Tetanospasmin, botulinum
Exotoxins that lyse cell membranes?
Alpha toxin (Staph, C. perfin, Pseudo), Streptolysin O (Streptococcus)
Exotoxins that are super antigens causing shock?
Toxic shock syndrome toxin (TSST-1), Exotoxin A. Superantigens cause non-specific widespread activation of T lymphocytes -> IL-1, IL2, TNF -> shock
Endotoxin function?
Edema, Nitric oxide, DIC/Death, Outer membrane, TNF-alpha, O-antigen, eXtremel yheat stable, IL-1, Neutrophil chemotaxis
Encapsulated bacteria? (Quellung reaction)
SHiNE SKiS = Strep pneumo, H. flu, N. meningitidis, E. coli, Salmonella, Klebs, Strep Group B
Obligate Anaerobes
Can’t Breathe Air = Clostridium, Bacteriodes, Actinomyces
Obligate Aerobes
Nagging Pests Must Breathe = Nocardia, Pseudomonas, MycoBacterium
Bacillus anthracis characteristics
Gram +, spore forming rod. Antiphagocytic D-glutamate capsule; Serpentine/medusa head on microscopy
Corynebacterium diphtheria characteristics
Gram + rod. Intracellular polyphosphate granules (stained with methylene blue; metachromatic)
Proteus mirabilis characteristics
Perithrichous flagella (meaning distributed evenly over cell)
Strep pneumo causes what?
MOPS - Meningitis, Otitis media, Pneumonia, Sinusitis
Optochin sensitive?
Strep pneumo
Cocci: + Catalase, + Coagulase
Staph aureus
S. aureus’ virulence factor?
Protein A - binds Fc-IgG -| complement activation and phagocytosis
Lactose-fermenting enteric bacteria?
macConKEE’S agar = Citrobacter, Klebsiella, E. coli, Enterobacter, Serratia; For Gram NEG rods. Black colonies, except E. coli which makes green.
Gram negative diplococci
Neisseria meningitidis and N. gonorrhoeae
Differentiate between Neisseria species?
Maltose fermenter = N. meningitidis; Maltose NF = N. gonorrhoeae
Farmer with SOB, fever, mediastinitis?
Pulmonary anthrax
Macrolides target what?
50S (Azithro, clarithro, erythro). 23S rRNA to prevent translocation
UA has nitrites positive, meaning
Gram NEG organism (So a gram + org like Staph saprophytic or enterococcus us would be nitrite NEG)
Chocolate Agar
H. flu. Factors V (NAD+) and X (hematin).
H. Flu - Distinguishing bacteriology? Diseases?
Chocolate (lysed RBC’s) agar req. Factors V (NAD+) and X (hematin). Gram NEG rod. Epiglottitis (Thumbprint sign), Meningitis, Otitis Media, Pneumonia. Can grow in blood agar with Staph, which will lyse RBC’s for X and V factor usage. Non-typable H. flu doesn’t have a capsule.
Optochin
OVRPS - Opthocin - Viridians is resistant. Pneumoniae is sensitive.
Bacitracin
B-BRAS - Bacitracin - Group B is resistent. Group A is sensitive.
EIEC
Invasive - necrosis and inflammation. dysentery-like. No toxin.
ETEC
Enterotoxigenic - produces heat-labile and heat-stable enterotoxins; Traveler’s diarrhea; no inflammation or invasion
EPEC
Enteropathogenic - No toxins. Flattens villi to prevent absorption. Diarrhea usu. in pediatrics
EHEC
Enterohemorrhagic - shiga-like toxin leading to HUS (micro thrombi leading to mechanical hemolysis and decreased renal blood flow; thrombocytopenia) O157:H7 is most common serotype
Two forms of Chlamydia
Elementary body - infectious, enters via endocytosis to become a Reticulate body - replicated in the cell by fission, then makes elementary bodies
Aminoglycosides attack what?
30S (bacteriacidal). Initiation complex formation and mRNA misread.
Tetracyclines attack what?
30S (bacteriostatic). A-site t-RNA binding.
Fluoroquinolones attack what?
DNA topoisomerases
Carbapenems attacks what?
Peptidoglycan cross-linking
Vanc attacks what?
Peptidoglycan synthesis by binding D-alanyl-D-alanine portion of cell wall precursors (which are glycoproteins). VRE has D-alanine-D-lactate
Sulfonamides attack what?
Folic acid synthesis (PABA to DHF)
Cephalosporins attack what?
Peptidoglycan cross-linking
Aminopenicillin coverage?
HELPSS kills enterococci - H flu, E coli, Listeria, Proteus, Salmonella, Shigella, enterococci
50S inhibitors
Buy AT 30, CCEL at 50 (Chloramphenicol - static, Clinda - static, Erythro - static, Linezolid)
30S inhibitors
Buy AT 30, CCEL at 50 (Aminoglycosides, Tetracyclines)
Aminoglycoside toxicity?
Neprhotoxicity, Neuromuscular blockade, Ototoxicity, Teratogen
Folate pathway abx?
Sulfonamides inhibit dihydropteroate synthase (PABA -> Dihydropteroic acid)Trimethoprim/pyrimethamine inhibit dihydrofolate reductase (Dihydrofolic acid to tetrahydrofolic acid)
Isoniazid toxicities?
INH = Injures neurons and hepatocytes; Vitamin B6 helps
Metronidazole coverage?
GET GAP on the Metro = Giardia, Entamoeba, Trichomonas, Gardnerella vaginalis, Anaerobes (Bacteroides, C. dificil), and w/ triple therapy for h. Pylori
Pseudomonas microbio?
Gram neg rod, Oxidase positive, non-LF, green-pigment producing. MOTILE
“Hot tub folliculitis”
Superficial Pseudomonal infection, usu. outbreaks at public swimming pools or hot tubs
Hepatitis D virus requires what exactly to replicate?
Must be encapsulated by HBsAg.
Organisms not typically covered by cephalosporins
LAME - Listeria, Atypicals (Chlamyida, Mycoplasma), MRSA, and Enterococci
Cephalosporin mech
Beta-lactam drug that inhibits cell wall synthesis but less susceptible to penicillinases; -cidal
Parvovirus presentation in adults?
Arthritis - mimicking RA but self-resolving
Enteric bacteria that can be transmitted via domestic animals?
Campylobacter jejuni - gram neg rod w/ filament (corkscrew movt)
3 main pathogens of HIV-associated esophagitis
Candida albicans - grey/white pseudomembranes; yeast cells and pseudohyphae
HSV-1 - small vesicles w/ punched out ulcers; eosinophilic intranuclear inclusions
CMV - linear ulcerations; intranuclear and cytoplasmic inclusions
Dimorphic fungi
Soporothrix (thorn prick SQ nodules), Coccidiodes, Histo, Blastomyces, Paracoccioides
What particular malarial schizonts are killed by Primaquine?
P. vivax and ovale.
Listeria microbio characteristics?
Gram + rod. Narrow zone of Beta-hemolysis on blood agar. Motility at 22 C and culture at 4 C. Tumbling motility. Cell-mediated immunity req, but neonates up to 3 months can’t. Tx = penicillin or ampicillin
3 types of schistosomiasis
Urinary (s. haematobium, Africa) - hematuria, dysuria, hydronephrosis, pyelo, bladder ca
Intestinal (mansoni or japonicum) - diarrhea, ulceration, Fe-def. anemia
Hepatic (mansonia, japonicum) - hepatosplenomegaly, portal htn
Diptheria toxin
AB-exotoxin. A subunit transfers ribose from NAD to His on EF-2 (peptide translocation) to inactivate it.
Pertussis toxin
Stimulates adenylate cyclase by disabling Gi, impairing phagocytosis; Whooping cough. Bordatella pertussis cultured on Bordet-Gengou.
Shiga toxin
Inactivate 60s ribosomal subunit
Defense against Giardia?
Secretory IgA impairs adherence of Giarda to duodenal and jejunal mucosa
What test differentiates staph aureus from the rest?
Coag POSitive staph aureus. Moses’ staph coagulated the Nile.
How is MRSA resistant to beta-lactamase resistant antibiotics?
Altered penicillin binding protein in peptidoglycan wall
Fried rice?
Bacillus cereus
Raw oysters
Vibrio parahaemolyticus - cholera like. Or Vibrio vulnificus - sepsis high mortality.
Raw eggs, raw chicken
Salmonella
Custard, mayo, salted meat
Staph aureus - heat stable enterotoxin; Your staff eat custard, salted meat, and mayonnaise
Transpeptidase?
Enzyme that cross-links peptide side chains for peptidoglycan
Composition of spore? What bacteria have them?
Keratin-like coat, dipicolinic acid, peptidoglycan. Bacillus anthraces, Clostridium perfringes, C. tetani
Composition and function of glycocalyx?
Mediates adherence to surfaces (esp. foreign surfaces like catethers). Made of polysaccharides
Where is the periplasm?
Between outer membrane and inner membrane in Gram-negatives.
Gram negative cocci
Neisseria
Gram positive rods
Clostridium, Corynebacterium, Bacillus, Listeria, Mycobacterium, Gardnerella; My Guard Listlessly Bakes Cor(y)n on the Cob
Branching filamentous bacteria
Actinomyces and Nocardia (weakly acid-fast); No Actin
Thayer-Martin?
VPN - Vanc, Polymyxin, Nystatin; Neisseria
Facultative intracellular
Some Nasty Bugs May Live FacultativeLY - Salmonella, Neisseria, Brucella, Mycobacterium Listeria, Francisella, Legionella, Yersinia pestis
Catalase + organisms
PLACESS for your Cat(s); Pseudomonas, Listeria, Aspergillus, Candida, E. coli, S. aureues, Serratia. Burkholderia cepacia.
Urease-positive organisms
(Cryptic) CHuck Norris Klebs Urease Positive w/ a Staph; Cryptococcus, h pylori, nocardia, klebsiella ureaplasma, Proteus, Staph epi/sapro
Yellow color associated organisms
Actinomyces israelii - granules; Staph aureus - pigment
Red pigment organism
Serratia marcescens. Serrated beef is RED
Green pigment organisms
Pseudomonas aeruginosa
What organisms secrete IgA protease?
Strep pnumo, H flu, Neiserria. IgA becomes ASHeN
ADP ribosylating A-B toxins?
Diptheria, exotoxin A, Shiga toxin, Shiga-like toxin, LT, Cholera toxin, Pertussis
Pseudomonas toxin and function
Exotoxin A; inactivates EF-2
ETEC toxin and function
Heat-labile (overactivates adenylate cyclase -> Cl- and water secretion). Heat-stable (overactivates guanylate cyclase -> reabsorption of NaCl and water); watery diarrhea
Bacillus toxin
Edema factor; mimics adenylate cyclase; Lethal factor - zinc-dependent protease that inhibits MAPK -> apoptosis
Cholera toxin
Overactivates -> Cl- secretion
Clostridium toxin
Tetanospasmin - spasticity, lockjaw, prevents release of inhibitory neurotransmitters; Botulinum toxin - flaccid paralysis, floppy baby, prevents stimulatory Ach signals at NMJ; Alpha toxin (perfingens) - lecinthinase that degrades cell membranes -> gas gangrene and hemolysis (dbl zone)
Strep toxins
Pyogenes has Streptolysin O (degrades cell membranes, Beta-hemolysis) and Exotoxin A (TSS) and Protein M (inhibits phagocytosis and activates complement)
Staph toxin
Toxic shock syndrome toxin (TSST01): MHC II and TCR brought in proximity outside of regular site -> overwhelming IFN-gamma and IL-2 release -> fever, rash, shock
Which bacteria will undergo transformation?
SHiN - Strep pneumo, H flu, Neisseria
What gene contains sex pills for conjugation?
F+
Genes for 5 toxins encoded in lysogenic phage
ABCDE - shigA-like toxin, botulinum, cholera, diphtheria, erythrogenic
Novobiocin?
Used to distinguish between coagulase NEG staph (cat +). No StRES - Novobiocin: Saprophyticus Resistant; Epidermidis Sensitive.
GAS characteristics
GAS = Strep pyogenes. Gram + cocci in chains. Catalase negative. Beta-hemolytic. B-BRAS. Bacitracin resistant. Pyrrolidonyl arylamidase (PYR)-positive. Impetigo, ARF, acute post-streptococcal glomerulonephritis, scarlet fever (sandpaper)
GBS characteristics
GBS = Strep agalactiae. Gram + cocci in chains. Catalase negative. Beta-hemolytic. B-BRAS. Bacitracin sensitive.
Strep pneumo characteristics
Gram + in chains. Catalase negative. alpha-hemolytic. OVRPS = Pneumo is optochin sensitive. Bile-soluble. Capsule is MAJOR virulence factor.
Viridians strep characteristics.
Gram + in chains. Catalase neg, alpha-hemolytic, optochin resistant. Bile INsoluble. NO capsule. Produce DEXTRANS (extracellular polysaccharides) via sucrose to adhere to FIBRIN. Therefore, viridians needs VALVE DAMAGE FIRST before it can attach to the fibrin clot on it to cause subacute bacterial endocarditis.
Gram + cocci in chains, catalase neg, gamma hemolysis
No hemolysis. Growth in Bile + 6.5% NaCl = Enterococcus. Bile w/o 6.5% NaCl = Nonenterococcus (e.g. Strep bovis)
Staph epidermidis clinical
Prostethic devies and intravenous catethers (glycocalyx?, biofilm production - extracellular polysaccharide matrix). Tx empirically w/ Van +/-rifampin/gent until sensitivities
Staph saprophyticus clinical
2nd most common uncomplicated UTI
Strep pneumo clinical
MOPS - Meningitis, Otitis media, Pneumonia, Sinusitis.
Viridians Strep clinical
Dental caries, bacterial endocarditis.
Strep pyogenes clinical
Pharyngitis, cellulitis, impetigo, scarlet fever, toxic shock0like syndrome, necro facitits, Rheumatic fever (Joints, heart, nodules, erythema marginatum, sydenham chorea), acute glomerulonephritis
Strep agalactiae clinical
Pneumonia, meningitis, sepsis (Babies). Produces CAMP factor (not cyclic AMP)
Enterococci (Group D) clinical
Normal colonic flora that are Pen G resistant. UTI, bilitary tract, subacute endocarditis. Bile + 6.5% NaCl
Strep bovis clinical
Group D strep. Bile w/o 6.5% NaCl. Bacteremia and endocarditis in colon ca patients.
Corynebacterium diphtheriae clinical
Diptheria - pseudomembranous pharyngitis (gray-white), pharyngitis, lymphadenopathy. Beta-prophage. Lab dx - blue and red granules and Elek test for toxin. Cysteine-tellurite agar (dark black, iridescent). Tx w/ antitoxin (passive immunity), Pen/erythromycin, DPT vaccine
C. tetani clinical
Tetanic paralysis blocking GABA release from Renshaw cells -> spastic paralysis, truisms, rises sardonicus.
C. botulinum clinical
Flaccid paralysis
C. perfingens clinical
Alpha toxin (lecinthase) -> gas gangrene and hemolysis. OR late-onset food poisoning w/ transient watery diarrhea.
C. difficile clinical
Toxin A - brush border of gut via neutrophils. Cytotoxin B - CYTOSKELETON (tight jx) disruption via actin depoly -> pseudomembranous colitis and diarrhea; Tx = metronidazle or oral vanc OR fidaxomicin (inhibits sigma unit of RNA pol)
Baccilus anthracis clinical
Cutaneous anthrax leads to boil-> ulcer w/ black eschar. Pulmonary anthrax -> flu-like to fever, pulmonary hemorrhage, mediastinisi, shock (Woolsorters’). Tx = Pen G or Doxy/cipro
Bacillus cereus clinical
Reheated rice syndrome. Spores. N/v within 1-5 hours by cereulide. Diarrheal type causes watery, nonbloody diarrhea and GI pain within 8-18 h.
Listeria monocytogenes clinical
Facultative intracellular. Only Gram + producing LPS. Amnionitis, septicemia, spontaneous abortion (That’s why NO unpasteurized cheese!) Meningitis. Gastroenteritis. Tx = penicillin, ampicilin.
Actinomyces clinical
Normal oral flora -> oral/facial ABSCESS that drain and form yellow granules; tx = pen + debridement. Gram +.
Nocardia clinical
Pulmonary infections in immunocompromised; of cut. infections in immunocompetent; tx = sulfa
TB clinical
Caseating granuloma w/ central necrosis and Langerhans giant cells. Ghon complex. Ghon focus in mid-zone. Reactivated fibrocaseous lesion in upper lobes. Fever, night sweats, wt loss, hemoptysis. Cord factor (my colic acid) correlates w/ virulence. Serpentine pattern.
M. leprae clinical
Lepromatous - lion-like facies, humoral Th2 response. Tuberculoid - few skin plaques with high cell-mediated immunity of Th1-response; Tx = dapsone and rifampin +/- clofazimine
Gram negative “coccoid” rods
H flu, Bordetella pertussis, Brucella, Pasteurella; Pastor Bruce Flu over-the Border.
Gram negative, oxidase POS
Campylobacter (42 C), Vibrio cholerae (alkaline), Helicobacter pylori (urease), or Pseudomonas (Gram - nrod)
N. gonoccoci clinical
STI. Gonorrhea, septic arthritis, neonatal conjuctivitis, PID, Fitz-Hugh-Curtis. Tx = Cef + (Azithro/doxy). Infection doesn’t provide resistance b/c of antigenic rearrangement of surface proteins.
N. meningococci clinical
Respi/oral secretions (using Pili). Meningitis, Waterhouse-Friderichsen. Tx = cef or Pen G. Ppx with RIFampin.
H flu clinical
Epiglottis, Meningitis, Otitis media, pneumonia.
Legionella pneumonphila clinical
Legionnaires’ disease = severe pneumonia with fever, GI, CNS, hyponatremia. dx = urine Ag test. No orbs on sputum. Pontiac fever = mild flu-like. Silver stain. Charcoal yeast culture with Fe and Cysteine. Aerosol from water. Tx = macrolide/quinolone
Pseudomonas aeruginosa clinical
PSEUDO = pneumonia, Sepsis, External otitis, UTI, Drug use + diabetic, Osteomyelitis, hot tub folliculitis, ecthyma gangrenosum (rapidly progressive necrotic cut lesions.) Tx = amino glycoside + extended spec Pen
Klebsiella clinical
4 A’s - Aspiration pneumonia, Abscess in lungs/liver, Alcoholics, di-A-betics. LF Gram Neg Rod. “Currant jelly” sputum.
Salmonella v. Shigella
Salmonella have flagella, hematogeneous, HS production, abx lengthen fecal excretion, can cause sepsis and typhoid fever. Shigella very low ID50, cell-to-cell, abx shorten duration of fecal excretion.
Campylobacter jejuni clinical
Bloody diarrhea. Comma oxidase + Gram - 42 C
Vibrio cholerae clinical
Rice-water diarrhea via enterotoxin that permanently turns on Gs. Sensitive to acid (less acidic = less organisms needed to infect) Common shaped, gram -, oxidase +, alkaline media
Yersinia enterocolitica clinical
Mesenteric adenines that looks like Crohn’s or appendicitis. “Pseudoappendicitis.” Pet feces, milk, pork. DAY-care.
H. pylori clinical
Gastritis, peptic ulcers. Gram - rod, catalase, oxidase, urease +. Tx = PPI + clarithro + amox/metro
Which are spirochetes?
BLT - Borrelia, leptospira, Treponema
Leptospira interrogans clinical
Flu-like, jaundice, photophobia w/ conjuctival suffusion. Surfers. Weil disease - more severe with kidney dysf(x). Tx w/ doxy.
Lyme disease clinical
FAKE a Key Lyme pie - Facial n. palsy (b/l), Arthritis, Kardiac block, Erythema migrans (red, ring-shaped w/ central clearing but often remains as patch); Tx = doxy, ceftriaxone
Syphilis stages
Primary - PAINLESS chancre. Dark-field, CLRL/RPR (non-specific). Secondary - disseminated disease with rash, condylomata lata. VDRL/RPR. Tertiary - Gummas (chronic granulomas that are PAINLESS -> ulcerate), Ascending aortic aneurysm (not dissection), neurosyphilis (tabes dorsalis), Argyl Robertson. Broad-based ataxia with romberg. Dx = spinal fluid w/ VDRL or RPR. Congenital - saber shins, saddle nose, VIII deafness, Hutchinson teeth.
Argyl Robertson pupil
Accommodates but not reactive to light
VDRL false positives
VDRL - viruses, drugs, rheumatic fever, lupus and leprosy
Gardnerella vaginalis clinical
Vaginosis. Fishy. Clue cells. Tx = metronidazole or clinda.
Treatment for Rickettsiae?
Doxy
Rocky Mountain Spotted Fever clinical
Rickettsia ricketsii. Tick. S. Atlantic. Wrist and ankles to trunk, PALMS and SOLES.
Typhus
Rickettsia typhi/prowazekii (flea or louse). TRUNK then spreads sparing palms and soles.
Chlamydia trachomatis clinical; serotypes?
PID, Reactive arthritis (Reiter syndrome), follicular conjuctivitis; ABC = Africa/Blindness/Chronic; D-K = everything else. L1-3 = lymphogranuloma venereum - small painless ulcers on genitals -> swollen lymph nodes that ulcerates (buboes). Azithro/doxy
Chlamydia pneumoniae/psittaci clinical?
Atypical pneumonia; aerosol. Azithro/doxy
Mycoplasma pneumonia clinical?
Walking pneumonia - insidious onset, HA, nonproductive cough, patchy infiltrate. COLD agglutinins -> hemolytic anemia. Eaton agar. Military + prison. Tx = macrolide, doxy, fluoroquinolone. NO CELL WALL = no pen. Require cholesterol for growth on media.
RF related to what organisms?
Group A Strep = Strep pyogenes
Most common cause of aseptic meningitis?
Enteroviruses - coxsackie, echo, polio; fecal-oral
Cryptococcus neoformans clinical
Meningitis is most common presentation (tx = amphotericin B, dx with CSF yeast). Immunosuppressed patients. Cryp pneumonia dx by MUCICARMINE or METHENAMINE silver staining of lung tissue and bronchoalveolar washings. Soil, pigeon. Sabouraud.
What organism from dental work -> endocarditis?
Viridians strep. Produce dextrans to help adhere to fibrin. Damaged valve -> endocarditis
H. flu vaccine composition?
Polyribosyl-ribitol-phosphate (PRP) a component of HiB capsule conjugated w/ deiphtheria or tetanus toxoid.
Bartonella henselae
Cat scratch disease (low fever, lymphadenopathy, self-limited), bacillary angiomatosis, culture-neg endocarditis.
Rubella
German measles. Maculopapular rash starting on head. Occipital and postAURICULAR lymphadenopathy. Congenital rubella = microcephaly, cataracts, deafness, patent ductus, pulmonic stenosis.
Prevnar vs. Pneumovax?
Prevnar = pneumococcal conjugate vaccine 13. Capsular polysaccharides attached to recombinant, inactivated diphtheria, which induces active immunity via T-cell-dept B-cell response w/ MEMORY. Efficacy in elderly, children s.
Most common cause of hydatid cysts?
Echinococcus granulosus (taepworm) - sheep, dog, foreign. Asymptomatic. UNIlocular. Hepatomegaly, RUQ, n/v. Eggshell calcification of liver. Aspiration of cyst = possible anaphylactic shock. Tx = albendazole
Typhoid fever
Salmonella typhi/paratyphi. Penetrate mucosa by M-cells -> liver, spleen, bone marrow. Hepatosplenomegaly. Intestinal hemorrhage w/ potential perf. ROSE spots on abdomen.
Scabies
Intense pruritic rash (usu. worse at night) on flexor surfaces of wrist, lat fingers, finger webs. Excoriation w/ small, crusted red papulse. Dx = skin scraping w/ mites, ova, feces
SW fungi path and diseases?
Coccidioides immitis - dimorphic fungi, thick-walled spherules w/ endospore. Pneumonia, meningitis. Case INC after earthquakes.
Ohio, Mississippi valleys valley - soil, bird, bat; path?
Histoplasma capsulatum - oval yeast cells w/in MACROPHAGES; hiSTOWaways in macrophages
Ohio, Mississippi valleys, Great lakes - soil; path
Blastomyces dermatidis - large, round yeast with doubly refractile wall and SINGLE broad-based bud; BLAST the Broad Bud, I’m SINGLE. Inflammatory lung disease. Skin and bone.
Latin America
Paracoccidioidomycosis. BUD, Take the Captain’s Wheel (Budding yeast in captain’s wheel). to Latin America!
Tinea versicolor - path, tx?
Malassezia furfur. Lipid degradation -> acid that damages melanocytes -> hypo/hyperpigmented. Tx = miconazole, Selenium sulfide. Spaghetti and meatballs. Italian accent - MalasEEEEzia, have some spaghetti and meatbawls.
Candida albicans
Systemic or superficial fungal infection. Tx = azole topical. Fluconazole, ampho, caspofungin for systemic. Pseudohyphae at 20 and Germ tubes at 37 (yeast grow hyphae).
Aspergillus fumigatus
Invasive aspergillosis (primary lung involvement in immunosuppressed with necrotizing pneumonia), colonizing aspergillosis (in old lung cavities; often asymptomatic or mild cough), allergic bronchopulmonary aspergillosis (ABPA) w/ wheezing, fever, and migratory pulmonary infiltrates. ACUTE angle (45 deg) branch. Condiophore w/ radiating chains of spores.
Mucor and Rhizopus pp.
Mucormycosis. Usu. DKA or leukemic patients. Proliferate in blood vessel wall -> penetrate CRIBiform plate -> brain -> frontal lobe abscess. Tx = amphotericin B. Sinuses. “Non-septate hyphae = wide-angle”
Pneumocystis jirovecii
PCP pneumonia - diffuse interstitial pneumonia. Inhaled. Disc-shaped yeast on methenamine silver stain. Tx/ppx = TMP-SMX, pentamidine. PPx when CD <200! (dapsone, atovaquone)
Sporotrichosis
SQ mycosis caused by sporothrix schenickii (dimorphic fungi; hyphae; cigar-shape; in plant material); thorn prick; reddish nodules -> ulcers; lymphatic spread!Dx - culture
GI protozoa
Giardia, entamoeba, cryptosporidium
Giardia
Giardiasis - malabsorption. Campers. Cysts in water. Dx - trophozoites or cysts in stool. Tx = metro. Maleficient Guards!
Entamoeba histolytica
“Amebic dysentery.” BLOODY diarrhea, liver abscess, RUQ pain. Dx = serology or trophozoites or cysts in stool; MULTI-nucleate trophozoites. Tx = metronidazole or iodoquinol for asymptomatic cyst passers. Prevalent in homosexual community.
Cryptosporidium
Severe diarrhea in AIDS. Dx = acid-fast ooctyes. Tx = prevention, nitazoxanide
CNS protozoa
Toxo, Naegleria, Trypanosoma
Toxoplasma gondii
Brain abscess (ring-enhancing) in HIV. Congenital toxo = chorioretinitis, hydrocephalus, intracranial calcifications. Meat, CAT feces. Dx = sero, tachyzoite. Tx = suilfadiazine + pyrimethamine
Naegleria fowleri
Rapidly fatal meningoencephalitis. Nalgene freshwater -> cribriform plate. Dx = amoeba in spinal fluid. Tx = amphotericin B might be effective
Trypanosoma brucei
African sleeping sickness - lymphadenopathy, fever, somnolence, coma. Transmitted by Tsetse fly. Dx = blood smear. Tx = Suramin for blood and melarsoprol for CNS
Differences between malaria subspecies?
Malariae = 72 hours. Vivax/ovale = 48 hrs, dormant form in LIVER requiring primaquine. Falciparum - IRREGular. Severe. Brain caps occluded.
Malaria treatment
Chloroquine - blocks Plasmodium heme polymerase -> mefloquine or atovoquone/proguanil. Quinidine if life-threatening but first check G6PD. Vivax/ovale sensitive for primaquine.
Babesia
Fever and hemolytic anemia. NorthEAST U.S. Asplenia increases risk of disease. Ixodes (i.e. lyme). Dx = Maltese cross. PCR. Tx = atovaquone + azithro. Babe in manger will carry cross breaking his blood.
Trypanosoma cruzi
Chagas disease - dilated cardiomyopathy, megacolon, megaesophagus. Reduviid bug feces. Dx - blood smear. Tx = benznidazole or nifurtimox.
Leishmania donovani
Visceral leishmaniasis (kala-azar) - spikign fevers, hepatospleno, pancytopenia. Sandfly. Dx = macrophages containing amastigotes. Tx = amphotericin B, sodium stibogluconate (binds heme)
Trichomonas vaginalis
Foul, green d/c. Strawberry cervix. Tx = metronidazole
Nematodes?
Roundworms. Ingested = EAT (Enterobius [pin], Ascaris [giant], toxocara). Cutaneous = SANd (Strongyloides, Ancylostoma and Necator [hook]). Bites = LOW (Loa loa, Onchocerca volvulus, Wuchereria bancrofti)
Enterobius vermicularis
Pinworm causing anal pruritis. Scotch Tape test. Tx = bendazole.
Onchoerca volvulus
Black onyx. Black flies, Black skin nodules, Black sight. Tx = ivermectin
Biliary tract disease, cholangiocarcinoma parasite
Clonorchis sinesis. Halabugi
Brain cysts, sz parasite
Taenia solium (cysticercosis) - undercooked pork.
Hematuria, bladder ca parasite
Schistosoma haematobium
Liver (hyatid) cysts parasite
Echinococcus granulosus. Dog feces.
Portal HTN parasite
Schistosoma mansoni/japonicum. Snails.
B12 deficiency parasite
Diphyllobothrium - raw freshwater fish
Microcytic anemia parasite
Ancylostoma, Necator
Two types of viral capsids
Icosahedral and helical
Phenotypic mixing vs complementation
Phenotypic mixing is mixed genome w/ coat. Complementation is that one virus’ functional protein helps another one that is co-infecting.
Killed viral vaccines?
A salK was Killed. RIP. (HAV, Rabies, Injected influenza, Polio). Induce humoral immunity.
Live attenuated vaccines
Humoral AND cell-mediated means NO booster. Live show! M(M)R. Sabin caught both the FLU and yellow fever. (smallpox, yellow, chicks)
Recombinant viral vaccines?
HBV, HPV
The only ssDNA virus. Only dsRNA virus.
Parvoviridae. Reoviridae. (Par’vn me, I’m single. I’m headed to Rio to get a double)
Circular DNA viruses
Pappilloma, polyoma, hepadnavirus. Polly enter the circle with Pappy and Heather.
+ssRNA viruses
Foggy morning?…“I’m POSitive that I went to a Retro(virus) Hepster (hepevirus) Toga(virus) party to eat Calcified(calicivirus) Pickles(picornavirus) and Flavored(flavirus) Corona(virus).”
Where do viruses replicate?
DNA viruses replicate in nucleus (except pox). RNA viruses replicate in cytoplasm (except retros and influenza)
Naked viruses?
Naked Hepster needs PAPP smears and CPR. PAPP = DNA (Papillomavirus, Adenovirus, Parvovirus, Polyomavirus). CPR = RNA (Calicivirus, PIcornavirus, Reovirus)
DNA viruses
“Because I’m HHAPPPPY!” Clap along…if you feel… (Hepadna, Herpes, Adeno, Pox, Parvo, Papilloma, Polyoma).
Pox virus is weird b/c
Well it’s DNA. But complex capsid and carries its own DNA-dependent RNA pol and doesn’t replicate in nucleus!
HSV-1
oral, keratoconjuctivitis, temporal lobe encephalitis, herpes labialis, latent in trigeminal. ds linear
HSV-2
Herepes genitalis, neonatal. Latent in sacral. Tzanck test of open skin vesicles - multinucleate giant cell.
HHV-3
VZV - chickenpox (vesicular rash on trunk spreading to face/limbs), shingles. Latent in dorsal root or trigeminal.
HHV-4
EBV - mononucleosis (fever, hepatosplenomegaly, pharyngitis, lymphadenoapthy). Infects B cells -> atypical lymphs. + monospot (heterophile ab’s aggultination of sheep or horse RBC’s to Ab’s in pt’s blood). Associated w/ hodgkin, Burkitt, nasopharyngeal ca. gp350 binds w/ CD21 (CR2) on B-cells
HHV-5
CMV - congenital, mono(NEG monospot), pneumonia, retinitis. OWL-EYE inclusions. ENVEloped. Latent in mononuclear. Binds to cellular integrins.
HHV-6/7
Roseola (Exanthem subitum). High fevers that can cause SEIZURE. Macular rash after fever.
HHV-8
Kaposi sarcoma. Immunocompromised. Dark/violaecous flat/nodular lesions.
Adenovirus
linear ds DNA virus that can cause acute pharyngitis, acute hemorrhagic cystitis, conjunctivitis, and pneumonia.
Parvovirus
ss, linear (neg) DNA. 5th disease in children. Aplastic crises in SCD. In fetus -> hydrous fettles. RBC aplasia and RA-like in adults
Polyomavirus
ds, circula. JC virus in PML for HIV. BK virus = bad kidney (transplant). Poly Letter viruses!
Poxvirus
ds, linear (LARGE) DNA. Smallpox. Cowpox. Molluscum contagiosum - flesh-colored dome lesions w/ central dimple.
Reovirus
ds RNA. Colorado tick fever (arbovirus), ROTAvirus (#1 fatal diarrhea in children, villous destruction w/ atrophy -> dec. Na+ absorption and loss of K+. Rio’s got lots of diarrhea)
Picornavirus
ss+RNA. PERCH = poliovirus, echovirus (aseptic meningitis), rhinovirus (binds CD54/ICAM), coxsackievirus (aseptic, hand/foot/mouth, myocarditis, pericarditis), HAV. Proteases cleave ONE LARGE polypeptide. (Small virus, Big Polypeptide).
Hepevirus
ss+RNA. Hepatitis E
Calcivirus
ss+RNA. Norovirus = viral gastro; Nor Cal!
Flavivirus
ss+RNA. HEP C. Yellow fever (high fever, BLACK vomitus, jaundice), dengue, St. louis, West nile
Togavirus
ss+RNA. Rubella (German toga party! “German measles” - fever, post auricular adenopathy, arthralgia. Congenital = blueberry muffin, extra medullar hematopoiesis, microcephaly, cataracts, deafness). Eastern/western equine encephalitis.
Retrovirus
ss+RNA. HTLV (T-cell leukemia), HIV
Coronavirus
ss+RNA. Common cold + SARS.
Orthomyxoviruses
ss-RNA. Influenza. Enveloped. HEMAGGLUTININ (viral entry, immunity gives Ab’s against these) and neuroaminidase (vision release). Disgusting orthopods, gave me the flu.
Paramyxoviruses
ss-RNA. Parainfluenza (croup - seal-bark, steeple sign), RSV, Measles, Mumps. All contain suface F protein (fusion) -> fusion of resp epithelial cells = multinucleate cells. Palivizumab (ab against F protein) prevents RSV pneumonia.
Rhabdoviruses
ss-RNA. Rabies; Rhabid animals = Rabies.
Filoviruses
ss-RNA. Ebola/Marbug.
Delta virus
ss-RNA. Circular.
NEG stranded RNA
Negatives Always Bring Polymerase Or Fail Replication. Arena, Bunya, Paramyxo, Orthomyxo, Filo, Rhabdo
Segmented viruses
Segment the BOAR to eat it! Bunya, Orthomyxo, Arena, Reo.
Genetic shift/drift
A sudden shift is worse (pandemic) than a graDual drift (epidemics)
Measles
Measles = Rubeola. Paramyxovirus. 3 C’s - Cough, coryza, conjuctivitis. Koplik spots of Buccal mucosa. Then comes a maculopapular rash from head down. Has hemagglutinin (surface adhesion) and matrix protein (viral assembly). Subacute sclerosing panecephalitis (SSPE) is a rare complications thought to be due to mutated measles (matrix protein) -> INTRACELLULAR replication and accumulation of viral nucelocapsis in neurons and oligo’s.
Mumps
Paramyxovirus. POM - Parotitis, orchitis, aseptic Meningitis. NO RASH. Can cause Leydig cell atrophy.
Rabies
Bullet-shaped virus. NEGRI bodies in purkinje cells of cerebellum and hippocampus. Long incubation. Retrograde. Fever, malaise -> agitation, photophobia, hydrophobia -> paralysis, coma, death. Bat, raccoon, skunk. Binds to Ach receptor
Hepatitis viruses
HAV is RNA picorna (Asymptomatic, Acute, Alone). HBV is DNA hepadnavirus. HCV is RNA flavivirus (Chronic, Cirrhosis, Carcinoma, Carrier). HDV is RNA delta virus. HEV is RNA hepevirus (Enteric, Expectant mothers, Epidemic - waterborne)
Hepatitis B serology
First HBsAg (incubation) w/ HBeAg=high transmission). Then high rise of Anti-HBc (core antibody, IgM -> IgG). Anti-HBe comes up = low transmission. Anti-HBs = immunity.
Hepatitis A serology
Anti-HAV (IgM) is best for active HAV. IgG for prior vaccination or infection.
Window period for Hep B?
Only Anti-HBe and Anti-HBc (IgM) shows up.
Three structural HIV proteins
env (cleaved from gp160 -> gp120 [CD4+ DOCK] + gp41 [FUSION and entry, transmembrane glycoprotein]), gag (p24 capsid protein), pol (the RT, aspartate protease, and integrate)
HIV binding and immunity
T-cells (CD4, CCR5early or CXCR4 late). Macrophages (CD4, CCR5). Homozygous CCR5 mut = immunity. Heterozygous = slower.
How diagnosis HIV?
R/o test w/ ELISA (often falsely neg in first 1-2 months and falsely positive in babies born to infected mothers) Confirm with Western blot. PCR used to determine RNA viral load. AIDS <200 CD4+.
AIDS with CD4<50
Meningitis (cryptococcus neoformans), CMV retinitis, MAC
AIDS with CD4<100
Histoplasma (LG fever, cough, hepatospleno, tongue ulcer), Toxoplasma in brain; Plasma gut at 100%!
AIDS with CD4<200
Cryptosporidium (chronic, watery diarrhea), PML (JC virus), PCP (Ground glass on imaging); Basline Crypt, PML, PCP danger
HIV patient with vascular proliferation. Biopsy shows neutrophilic inflammation.
Neutrophilic = Bartonella henselae. Lymphocytic = HHV-8.
Basic prion disease mech
Transmission of normal protein (alpha-helical) into Beta-pleated form
After influenza, secondary bacterial pneumonia organisms
Strep pneumo, Staph aureus, Haemophilus influenzae
Zidovudine
NRTI. Binds and inhibits mammalian cellular and mitochondrial DNA polymerases -> bone marrow suppression
Rifampin
Inhibits bacterial DNA-dependent RNA polymerase
Pneumonia in neonates (<4 weeks)
GBS, E.coli
Pneumonia in children
Runts May Cough Chunky Sputum - RSV, Mycoplasma, Chlamydia trach, C. pneumo, Strep pneumo
Pneumonia in adults <40
Mycoplasma, C. pneumonia, S. pneumonia
Pneumonia in adults 40-65
Strep pneumo, H. flu, anaerobes (CBA), Viruses, Mycoplasma
Pneumonia in elderly
Strep pneumo, influenza, anaerobes, H flu, Gram Neg rods
Atypical pneumonia
Mycoplasma, Legionella, Chlamydia. A weird name: My Clam Legion!
Postviral pneumonia
Staph, H flu, Strep pneumo
Meningitis in <6 mo
E. coli, GBS, Listeria
Meningitis in Children
Strep pneumo, N. meningitidis, H flu, Enterovirus
Meningitis in adults
Strep pneumo, N. meningitidis, Enterovirus, HSV
Meningitis in elderly
Strep pneumo, Gram neg rods, Listeria
CSF in meningitis
Bacterial (high opening pressure, PMNs, high protein, low glucose). Viral (Normal/high pressure, high lymphs, normal/high protein, NORMAL sugar). Fungal/TB (high pressure, high lymphs, high protein, low sugar)
Osteomyelitis - cause per RF
Baseline Staph. Sexually active N. gon. DM + IV = Pseudo + serratia. Sickle cell = salmonella. Prostethic = Staph aureus/epidermidis. Vertebral involvement = Potts. Cat/dog = Pasteurella.
UTI w/ + urease
Klebsiella, Proteus
Top UTI bugs
E. coli, Staph sapro, Klebs
ToRCHeS
Toxo (cat, meat, chorio, hydro, intracranial calc), Rubella (resp droplets, PDA, cataracts, deafness, blueberry muffin), CMV (sexual contact, hearing loss, sz, petechial rash, blueberry muffin), HIV (sexual, recurrent infection and diarrhea), HSV-2 (skin or mucous, encephalitis, vesicular lesions), Syphilis (sexual, stillbirth, hydrops fetalis, Hutchinson, saddle, short maxilla, saber shins, VIII deaf)
Coxsackievirus type A
Hand-foot-mouth; vesicular rash on palms and soles. Vesicles in oral mucosa
Painful genital uncler w/ inguinal adenopathy
Chancroid = Haemophilus ducreyi; tx = azithro
PID organisms
Chlamydia trachomatis (subacute) and N. gonorrhea (acute). Comps include salpingitis, endometritis, hydrosalpinx, tubo-ovarian abscess. Fitz-Hugh-Curtis syndrome = adhesions of peritoneum to LIVER.
Hyperalminentation RF for what infection?
Candida
Neutropenia –> infection?
Candida albicans (systemic), aspergillus
Organ transplant -> infection?
CMV
Hands and feet rash?
Coxsackie A, Treponema pallidum, Rickettsia ricketsii
Most common organism associated with endocarditis in IV drug users?
Staph aureus. Tricuspid endocarditis
Pen G,V - mech, use, tox, resistance
Binds penicillin-binding proteins (e.g. transpeptidase cross-linking of peptidoglyans), activate autloytic. Gram POS + N. meningitides and Treponema. Cidal for cocci and gram + rods and spirochetes. HS reaction, hemolytic anemia. Penicillinase can cleave Beta-lactam ring.
Aminopencillins
Ampicillin, amoxicillin. HELPSSS kill enterococci. H flu, E coli, Listeria, Proteus, Salmonella, Shigella, entero. Hypersensitivity, rash, pseudomembranous colitis. Penicillinase.
Pencillinase-resistant penicillins
Oxacillin, nafcillin, dicloxaxillin. Bulky R group blocks access of Beta-lactamase to ring. Use for Staph aureus except MRSA (altered penicillin bending protein). Hypersensitivity, interstitial NEPHRITIS.
Antipseudomonals
Ticarcillin, piperacillin. Same mech as Pen. Susceptible to pencillinase so use with Beta-lactamase inhibitors. Hypersensitivity.
Beta-lactamase inhibitors.
CAST = Clavulanic Acid, Sulbactam, Tazobactam. The CaST for Betas has been set.
Cephalosporin coverage?
1st - PECK (Proteus, E coli, Klebs)..2nd - HEN PEcKS (H flu, Enterobacter, Neisseria, Klebs, Serratia)..Don’t cover LAME - Listeria, Atypicals, MRSA, and Enterococci
Cephalosporin names
1st - cefazolin, cephalexin. 2nd - cefoxitin, cefaclor, cefuroxime. 3rd - ceftriaxone, cefotaxime, ceftazidime. 4th - cefepime (better against Pseudo and gram+). 5th - ceftaroline (broad + MRSA but NOT pseudo).
Aztreonam
Monobactam resistant to Beta-lactamases. Synergistic w/ aminoglycosides. Only gram-NEG rods.
Carbapenems
Imipenem, meropenem, ertapenem, doripenem. Always administerd with CILASTATIN (inhibitor of renal dehydropeptidase I) to dec. inactivation. Gram POS cocci, Gram-NEG rods, and anearobes. SE’s = GI, skin rash, Seizures
Vanc usage and tox
Gram + ONLY (MRSA, enterococci, C. dificile). Tox = Nephro, oto, Thrombophlebitis, flushing.
Macrolide specific mech
Translocation (50S) by binding 23S rRNA. Static. Same with Clinda. MacroSLIDES
Aminoglycosides
Gentamicin, Neomycin (abd surgery), Amikacin, Tobramcin, StreptoMYCIN. cidal. Inhibit INITiation -> misread mRNA.. Req O2 for uptake! Severe Gram-NEG rod, synergistic w/ beta-lactam. Nephrotox, Neuromuscular, Ototox, Teratogen. Resistant - bacterial transferase enzymes inactivate. Do NNOT MISREAD aminoGlycosides. Enterococci resistance via modifying enzymes that transfer chemical groups to drug (plasmids/transposons)
Tetracyclines
t for TRNA binding. Tetracyclnine, doxycycline, minocycline. Stati. Doxy helpful for RENAL failure. No milk or antacids. Prisoner in cell plays tetris! Used for Borrelia, Mycoplasma, Ricketsia, Chlamydia. SE - Discolored teeth, GI, photosensitivity. NO preg. Resistance via dec. uptake or increased efflux.
Macrolides
Azithromycin, clarithromycin, erythromycin. Use for atypical pneumonias (Mycoplasma, Chlamydia, Legionella), STD, Strep. Tox = MACRO = gi Motility, Arrhythmia by long QT, Cholestatic hepatitis, rash, Eosinophilia. Resistant via methylation of 23S rRNA.
Chloramphenicol
Blocks 50S peptidyltransferase. Static. In the Rockies, we use Gray Clorox for Meningitis. Meningitis (H flu, N. men, Strep pneumo) and RMSF. Tox = anemia, asplastic anemia, gray-baby. Resist by plasma-encoded acetyltransferase to inactive.
Clindamycin
Blocks translocation of 50S. Static. Use for Anaerobes ABOVE diaphragm (aspiration pneumonia, lung abscess, oral infection) + GAS. Tox = C. dif
Sulfonamides
Sulfamethoxazole (SMX), sulfisoxazole, sulfadiazine. Inhibits folate synthesis (dihydropteroate synthase). Used for gram +, gram -, Nocardia, Chlamydia. Tox - hypersensitivity, G6PD hemolysis, nephro, photo, kernicterus in infants, displace drugs(like warfarin) from albumin. Resi - altered enzyme, dec. uptake, or inc. PABA synthesis.
Trimethoprim
Inhibits dihydrofolate reductase. Static. TMP-SMX used for sequential folate synthesis block for UTIs, Shigella, Salmonella, PCP, toxo ppx. Tox - Megaloblastic anemia, leikpenia, granulocytopenia.
Fluoroquinolones
Ciprofloxacin, norfloxacin, levofloxacin, etc. Inhibits topo II and topo IV. Cidal. DONT TAKE with PPIs. Use for Gram-neg rodss of urinary and GI, Neisseria, some gram POS. Tendon rupture, leg cramps, myalgias. Contra = pregnant, nursing, children). Resist - chromosome-encoded mutation in DNA gyrase, plasma for efflux
Metronidazole
Forms free radicals to damage DNA. Cidal, antiprotozoal. GET GAP on the Metro. Anaerobics BELOW diaphragm. Tox - disulfiram-like reaction w/ alcohol. HA, metallic.
PPx for Mycobacterium tuberuclosis, avium, leprae.
INH, Azithro/rifabutin, N/A
Tx for Mycobacterium tuberculosis, avium, leprae.
RIPE, Azithro/clarithro + ethambutol, dapsone + rifampin +/- clofazimine
INH
Dec. synthesis of mycolic acid (NEEDS bacterial catalase-peroxidase). Tox = INH - injures neurons and hepatocytes.
Rifamycins
Rifampin and rifabutin. Inhibits DNA-dependent RNA polymerase. 4 R’s = RNA pol inhibitors, Ramps up microsomal P450, Red/orange body fluids, Rapid resistance if alone, RifAMPin ramps up P450 BUT rifaBUTin does not.
Pyrazinamide
? mech. May acidify intracellular. Tox - hyperuricemia, hepato
Ethambutol
Blocks arabinosyltransferase -> decreases carbohydrate polymerization of mycobacterium wall. Tox = OPTIC NEURITIS
Endocarditis ppx w/ dental
Penicillins
Gonorrhea ppx
Ceftriaxone
Hx of UTI ppx
TMP-SMX
Meningococcal inf. ppx
Cipro or rifampin (children)
GBS POS pregnant women ppx
Ampicillin
Newborn conjuctivitis 2/2 gonococcal/chlamydial
Erythromycin
Post surgical ppx against Staph
Cefazolin
Syphilis ppx
Benzathine pen G
HIV Ppx
CD4 Azithromycin ppx for Myobacterium avium
Sterol pathway for antifungals
Squalene -(squalene epoxidase, terbanifine)-> squalene epoxide -> lanosterol -(14-alpha-demethylase, azoles)-> ergosterol -> membrane
Amphotericin B
Binds ergosterol and forms membrane pores. For serious systemic mycoses (Cryptococcus, Blasto, Coccidio, Histo, Candida, Mucor). Intrathecal available. K+ and Mg+ sup. Tox = NEPHROTOX, fever, chills, hypotension, arrhythmias, anemia, IV phlebitis.
Nystatin
Binds ergosterol and forms pores. Only TOPICAL.
Azoles
Inhibits P450 enzyme (14-alpha-demethylase) that forms ergosterol. Fluconazole for cryptococcal meningitis ppx in AIDS. Itracon for Blasto, COccidio, HIsto. Tox - testosterone synthesis inhibition (esp keto), liver
Flucytosine
Converts to 5-FU (thymidylate synthase inhibitor). Cryptococcus meningitis. Used w/ amphotericin B.
Echinocandins
Caspofungin, micafungin, anidulafungin. Inhibits synthesis of Beta-glucan to prevent CELL WALL synthesis. Used for invasive aspergillosis and Candida. Tox - GI and flushing.
Terbinafine
Inhibits SQUALENE EPOXIDASE. Used for dermatophytoses. tox - GI, HA, hepato, taste.
Griseofulvin
Interferes with MT. Oral tx for superficial infections (tines, ringworm). Teratogenic, carcinogenic, confusion, HA.
Chloroquine
Blocks detoxification of heme into hemozoin -> heme accumulation to kill plasmodia. Used for species other than falciparum b/c of resistant via membrane pump. Tox - retinopathy, pruritus.
Neruaminidase inhibitors
Zanamivir, olsetamivir. For influenza A and B.
Ribavirin
Converted to 5’ phosphate derivative and then INHIBITS viral mRNA Capping and BLOCKS RNA-dept RNA pol. Modulates better immune response via Th1. Used for RSV (bronchiolitis) and chronic HCV. Tox - SEVERE teratogen. hemolytic anemia.
Guanosine analogs
Acyclovir, famciclovir, valacyclovir, and ganciclovir.
HSV/VZV guanosine analogs
Acyclovir, famciclovir, valacyclovir. Phosphorylated by viral thymidine kinase but not cellular cells. Inhibits viral DNA pol by chain termination. HSV and VZV. Weak against EBV and none against CMV. No effect on latent forms. Tox - crystalline ephropathy. Res - mutated viral thymidine kinase.
Ganciclovir
5’ monophosphate framed by CMV viral kinase, with triphosphate formed by cellular kinases. Inhibits viral DNA pol. Tox - leukopenia, neutropenia, thrombocytopenia, renal. Resist - mutated pol or lack of viral kinase.
Foscarnet
A pyrophosphate derivative that reversibly inhibits viral DNA and RNA pols via chain elongation. Doesn’t require activation. Used for CMV retinitis, acyclovir resistant HSV. Nephrotoxic. Rest - mut viral pol.
Cidofovir
viral DNA pol, no activation. CMV retinitis or acyclovir-resistant HSV. Nephrotoxicity (Req. probenecid and IV saline)
HAART therapy
2 NRTIs + 1 NNRTI/1 PI/1 Integrase inhibitor. Initiated with AIDS-defining illness, low CD <500, or high viral load.
Nucleoside reverse transcriptase inhibitors (NRTIs)
All nucleosides except tenofovir (nucleotide) that competitively inhibits binding to RT to terminate DNA chain (lacking 3’ OH group). ABC, ddl, FTC, 3TC, d4T, TDF, ZDV=AZT. Tox - bone marrow suppression reversed with G-CSF and EPO, peripheral neuropathy, lactic acidosis, rash, anemia (ZDV)
Protease Inhibitors
NAVIR tease a protease. HIV-1 protease (pol gene) inhibitor. Tox - hyperglycemia, n/d, lipodystrophy (Steroid-like redistribution of fat - buffalo), nephro and hematuria (indinavir)
NNRTIs
Efavirenz, Nevirapine, Delavirdine.
Integrase inhibitors
Raltegravir. Tox - hyperchol.
Fusion inhibitors.
Enfuvirtide binds gp41. Maraviroc binds CCR5 on Tcells to inhibit gp120 interaction.
Necrotizing fasciitis microbes
Strep pyogenes, Staph aureus, Clostridium perfinges.
Strongyloidiasis
Filariform (infectious) larvae in soil (fecal). Penetrate skin, hematogenous spread to lungs, travel up tree to pharynx, GI -> adults lay eggs in mucosa -> rhabditiform (non-infectious) larvae. Tx = ivermectin.
Alcohol, chlorhexidine, hydrogen peroxide, and iodine
Etoh (disrupt membrane, denature proteins), Chlorhexidine (disrupt membrane,coag cytoplasm), hydrogen peroxide (free radicals that oxidize cell), iodine (halogenation of proteins and nucleic acids). Only last two are sporicidal.
What HPV serotypes associated with anal and cervical squamous cell carcinoma?
16, 18, 31
E. coli virulence factors
LPS (bacteremia and septic shock), K1 polysaccharide (neonatal meningitis), Shiga-like, HL/HS, P fimbrae (UTI)
Gram negative rods, Non-fermenters, Oxidase Positive —> how differentiate?
TSI agar (Triple sugar iron) agar. No H2S production = Shigella. Yes H2S prod. (black) = Salmonella or Proteus. Salmon is Sulfur Smellier!
Acinetobacter baumanii
Gram - rod. Non-LF. Catalase +. Hospitalized or immunodeficient. Pneumonia, UTI.
Bacteroides fragilis
Gram NEG anaerobic rod. Normal GI flora can cause abdominal abscess (e.g. recent surgery). Tx = Metro or Pip-Taz
Reassortment vs. Recombination
Reassortment = changes in genomic composition during co-infection with two SEGMENTED viruses that exchange whole genome segments (e.g. influenza). Recombination = exchange of genes via crossing over between two viruses w/ NON-fragmented ds-DNA genomes. Phenotypic mixing is co-infection -> different nucleocapsid ONLY
The most common cause of bacterial meningitis in all ages?
Strep pneumo = lancet-shaped Gram+ cocci in pairs (alpha, Opto sens)
Only enveloped virus class that obtains its envelope from the nuclear membrane
Herpesviruses
Staphylococcal Scalded Skin Syndrome (SSSS)
Staph species producing exfoliation exotoxin. Nikolsky’s sign (skin slippage w/ gentle pressure), epidermal necrolysis, fever, pain. Usu. infants and children.
Inactivated influenza vaccine against?
Hemagglutinin Ag. Ab’s inhibit binding of hemagglutinin to sialyated receptors on host cell membrane to prevent endocytosis of live virus.
Nasophryngitis, laryngotracheitis, and bronchiolitis etios?
Naso - Rhino, influenza, corona. Croup - parainfluenza. Bronchiolitis - RSV.
Ototox abx
Aminoglycosides or vancomycine
CBC should be checked for these abx
Chloramphenicol (aplastic anemia), dapsone (agranulocytosis), TMP-FMX (megaloblastic anemia)
Optic neuritis causing abx?
Ethambutol
Reactive arthritis
Reiter syndrome. “Can’t see, can’t pee, can’t climb a tree.” 80% HLA-B27. Chlamydia, Campy, Salmonella, Shigella, Yersinia inf. preceding by 2-6 weeks
Only viruses capable of genetic shifts through reassortments?
Viruses with segmented genomes = orthomyxovirus (influenza), rotaviruses, bunyavirus
Heat-killed bacteria vaccines?
Bordetella pertussis, Vibrio cholera, Yersinia pestis
Recombinant bacterial outer surface protein vaccine?
Borrelia burgdorferi
Inactivated toxin vaccines?
Corynebacterium diphtheria and Clostridium tetani
Live attenuated vaccines?
BCG, Francisella tularensis, Salmonella typhi, flu (I think)
Only RNA viruses that replicate in the nucleus?
Influenza (Orthomyxovirus) and Retroviruses like HIV
Polysaccharide conjugated vaccines?
Strep pneumo, Neisseria meningitidis, H. flu. Carrier proteins include mutant nontoxic diptheria, tetanus toxoid, and N. meningitidis outer membrane protein complex
Entecavir
Guanosine analog used for HBV infections.
Lamivudine (is not Zidovudine)
Cytosine analog used for HBV DNA pol and HIV RT. Must be phosphorylated into triphosphate (active) form.
Didanosine tox
Pancreatitis
