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40 Cards in this Set
- Front
- Back
- 3rd side (hint)
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S. aureus - disease |
Food poisoning, SSS (exfoliative toxin; kidneys), Bullous impetigo (large pustules), Folliculitis --> Furuncles (boils) --> Carbuncles (fever + chills) |
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S. aureus - lab dx |
PYR(-), ornithine(-), grows on 7.5% NaCl, ferments mannitol |
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MRSA |
mecA --> altered penicillin-binding proteins Oxacillin resistant (zone <12mm) Cefoxitin resistant (zone <21mm) <--definitive |
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VISA / VRSA |
VISA: Overproduction of Vancomycin target VRSA:VanA operon alters Vancomycin target |
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S. epidermidis |
Hospital acquired infections: UTI, prosthetic valve endocarditis |
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S. saprophyticus |
Adheres more effectively to epithelial cells lining urogenital tract Novo resistant |
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S. lugdanensis |
Endocarditis (particularly aggressive), can clinically mimic S. aureus infections Ferments mannitol, PYR and Ornithine positive (only slug) Slide coag pos mecA encodes oxacillin resistance Often hemolytic; grows slower on choc; colonies very white |
Disease, lab dx, colonies, resistance |
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Micrococcus |
Rarely causes infections. GS: tetrads, larger than Staph Yellow colonies, modified oxidase +, bacitracin susceptible |
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Cefoxitin |
Better than oxacillin for detection of methicillin resistance. Better inducer of mecA-mediated resistance |
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D test |
Clindamycin for Staph skin infections. msrA: erythromycin resistant + clindamycin susceptible erm: erythromycin resistant + clindamycin induced resistance (D-test +) |
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S. intermedius |
VP neg, PYR pos |
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S. pyogenes - disease |
Pharyngitis --> rheumatic fever (heart valves) or acute glomerulonephritis (kidney fxn) Scarlet fever (red rash on upper chest d/t pyrogenic exotoxin) --> STSS Impetigo (localized skin disease; vesicles --> lesions --> crusts w/in days), cellulitis (deeper invasion), otitis media, necrotizing fasciitis ("flesh-eating disease") Erysipelas |
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S. pyogenes - virulence factors |
M protein (protective) - inhibits phagocytosis Pyrogenic exotoxin; superantigen (scarlet fever --> increased cytokines --> STSS) Streptokinase: dissolves clots Hyaluronic acid capsule: inhibits phagocytosis, can mask Ags Streptolysin O (ana) + S (aer): lyse RBCs, plts, neuts Hyaluronidase |
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S. pyogenes - lab dx / drugs |
Pinpoint colonies (<1mm), translucent, large beta Antistreptolysin (ASO) determines recent infection Penicillin (or erythromycin) - drug of choice |
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S. dysgalactiae (subsp. equisinilis) |
Gp C or G. Same clinical spectrum as Gp A and similar morphology |
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S. agalactiae - disease |
Neonates --> sepsis, meningitis (during birth) Postpartum fever, osteomyelitis, wound infections, UTI *normal flora of GI (25% females: vaginal) |
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S. agalactiae - lab dx |
Colonies >1mm, flat, creamy, small beta (some non) CAMP test and hippurate hydrolysis = + Bacitracin resistant, PYR neg Todd-Hewitt broth: colistin (or gentamicin), malidixic acid @ 35'C 18-24h --> SBA @ 35'C, 5% CO2, 24h |
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Group D Strep |
Normal fecal and oral flora Wound, UTI, abdominal abscess Blood culture = indicator of colon cancer BE+, NaCl/PYR=neg S. Bovis |
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Enterococcus |
UTIs, bacteremia VRE d/t peptidoglycan cross-link target E. faecium (common VRE), E. faecalis (grows in tellurite) Weak catalase + BE+, NaCl/PYR=pos |
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Viridans strep |
Normal flora of oral, resp, GI Major cause of bacterial endocarditis w/ damaged heart valves. Also wound infections, brain abscesses, and may enter blood after dental proc. Optochin resistant, BS=neg, BE=neg
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S. mutans group |
Most common viridans strep Oral cavity; dental caries |
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S. bovis |
Gp D antigen; blood cultures |
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S. anginosis |
Abscesses; butterscotch smell |
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S. pneumoniae |
Normal upper resp flora Lobar pneumonia (eldery + alcoholics), otitis media (children), meningitis Sputum: rust colored from blood GPDC, lancet-shaped; umbilicated, depressed centers SBA w/ 5-10% CO2 @ 48hrs (>48h = nonviable) Optochin sensitive Penicillin or erythromycin |
Flora, disease, Sputum, GS, growth/colonies, lab dx |
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Gemella |
Endocarditis, meningitis, brain/lung abscesses, osteomyelitis PYR, LAP = + BE = - Easily decolorizes |
Pyr, lap, be, GS |
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Leuconostoc |
Osteomyelitis, ventriculitis, post surgical endophthalmitis, bacteremia in neonates Vancomycin = resistant PYR, LAP, catalase = neg BE, NaCl = pos |
PYR, LAP, catalase, BE, NaCl |
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Nutritionally Variant Strep |
Abiotrophia and Granulicatella Satellites, requires sulfydryl compounds, B6 (pyridoxal or pyridoxamine) Normal oral flora Otitis media, bacteremia (+ bld cult, NG on s/c --> streak SBA w/ S. aureus), endocarditis (needs surgery) |
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Aerococcus |
Airborne Bacteremia, endocarditis, UTIs Resemble viridans on culture, similar to staph on GS (tetrads/clusters) Grows on 6.5% NaCl A. viridans = BE+, PYR+ A. urinae = BE-, PYR- |
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Listeria monocytogenes |
Listeriosis/meningitis (dairy products) Normal flora of vagina/intestines Small colonies, narrow zone B-hem Umbrella @ RT, tumbling on wet mount Grows @ 4'C (cold enrichment) CAMP+ ("block" hemolysis), Hippurate hydrolysis = pos Catalase = pos BE = pos |
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C. diphtheriae |
Diphtheria (pseudomembrane from cell necrosis + exudate at back of throat) GS: small pleomorphic rods, pallisades, club shaped Methylene blue shows metachromatic granules (Babes-Ernst) Elek test: uses antitoxin Cystine-tellurite, tinsdale = brown halo, black colonies Loeffler (enhances pleomorphism + granules) Penicillin/erythromycin Urease/pyrazidamidase = neg Nitrate = pos |
Disease, GS, media, drugs, lab dx |
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C. jeikeium |
Nosocomial infx (prosthetic device implants -> endocarditis) Lipophilic, strict aerobe Urease/pyradizamidase = pos Nitrate = neg |
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C. urealyticum |
Lipophilic, strict aerobe UTIs Urease = pos Does not ferment glucose |
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C. striatum |
Not lipophilic |
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Arcanobacterium |
A. haemolyticum (pharyngitis, wound tissues; CAMP inhibition test) A. pyogenes (mucous membranes of farm animals) Small, beta-hem, catalase(-), nonmotile |
Haemolyticum, pyogenes, cat, mot |
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Erysipelothrix rhusiopathiae |
Contact w/ infected animals (fisherman, butchers, vets, rose growers) Cellulitis (lesions resembling erysipelas from GpA) Nonmotile, test tube brush Catalase neg H2S+ |
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Nocardia asteroides |
Immunocomp w/ chronic pulm disorders Pleomorphic, branching, in chains, beaded Partially acid-fast Cat(+), nonmotile 6 weeks to grow Exudate --> filamentous organisms w/ sulfer-life pus |
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Bacillus spp. |
GS: boxcar Cat(+) Cultures: large, flat, ground glass |
Gs, cat, cult |
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B. anthracis |
Zoonosis, cutaneous (necrotic skin lesions - black eschars), pulmonary (wool-sorter's) Large, nonhemolytic Medusa-head colonies; nonmotile
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B. cereus |
Food poisoning d/t preformed toxins "fried rice" Beta-heme w/ irregular edges Motile |
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S. schleiferi |
Slide coag pos. Pyr pos |
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