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Flashcards in Micro Deck (127)
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61

most common cause of sinusitis

Step pneumo

62

Strep pneumo vaccine

- Adults: polysaccharide w/o protein (23 valent) --> T cell independent --> IgM
- Kids: conjugated to protein (7 valent) --> robust response of T cells and B cells --> IgG

63

Strep viridans

Dental caries (mutans and mitis)
Subacute bacterial endocarditis at DAMAGED heart valves (sanguinis)
Makes dextrans --> bind to fibrin-platelet aggregates on damaged heart valves

64

Strep pyogenes (Group A Strep)

PYR +
M protein --> rheumatic fever
ASO titer detects infection
Pharyngitis --> rheumatic fever and PSGN
Scarlet fever

65

Most common cause of erysipelas (rash)

Strep pyogenes

66

Acute Rheumatic Fever
- Strep pyogenes

Polyarthritis, carditis, subcutaneous nodules, erythema marginatu, sydenham chorea

67

Scarlet Fever
- Strep pyogenes

Blanching, sandpaper-like body rash
Strawberry tongue
Circumoral pallor
Erythrogenic toxin +

68

Strep agalactiae (Group B Strep)

- Pneumonia, meningitis, & sepsis in babies
- CAMP factor --> enlarges area of hemolysis formed by S. aureus
- Hippurate test +
- PYR+

69

Most common cause of neonatal meningitis

Strep agalactiae

70

Strep bovis

Subacute endocarditis
COLON CANCER

71

Enterococci

UTI, biliary tract infections, subacute endocarditis
PYR +
VRE --> nosocomial infections
Ca grow in 6.5% NaCl and bile

72

Bacillus anthracis

Spore-forming rod
Anthrax toxin
Polypeptide capsule (D-glutamate)
Cutaneous anthrax --> black eschar
Pulmonary anthrax --> pulmonary hemorrhage, mediastinitis, shock (WOOL, GOAT HAIR)
Edema factor --> increases cAMP --> inhibits phagocytosis
Lethal factor --> protease --> cleaves MAPK --> tissue necrosis

73

Bacillus cereus

Reheated rice syndrome
Spores
Cereulide (preformed toxin)

74

Clostridium tetani
- PUNCTURE WOUND

Tetanospasmin --> blocks release of inhibitory GABA And glycine from Renshaw cells in spinal cord --> spastic paralysis
Rx: antitoxin +/- vaccine booster, diazepam, wound debridement

75

Clostridium botulinum
- Adults: improper food canning (preformed toxin)
- Babies: honey (spores)

Produces heat-labile toxin (protease) that inhibits ACh release --> flaccid paralysis
Rx: antitoxin

76

Clostridium perfringens
- Motorcycle accidents
- Penetrating wound form military combat

Alpha toxin (lecithinase) --> myonecrosis and hemolysis
Spores in undercooked food --> heat-labile enterotoxin --> food poisoning (late onset)

77

Clostridium difficile
- Clindamycin or ampicillin use
- PPI use

Toxin A: enterotoxin --> binds to brush border of gut
Toxin B: cytotoxin --> actin depolymerization --> cytoskeletal disruption --> diarrhea --> pseudomembranous colitis
Dx: stool toxins via PCR
Rx: metronidazole or oral vancomycin

78

Corynebacterium diptheriae

Exotoxin encoded by beta-prophage --> ADP-ribosylation of EF-2 --> inhibits protein synthesis
Psuedomembranous pharyngitis
Dx: metachromatic (blue and red) granules, Elek test+ (toxin)
Black colonies on cystine-tellurite agar

79

Diphtheria vaccine

Toxoid
IgG response against exotoxin B

80

Listeria monocytogenes

Pregnant women
Rocket tails - actin polymerization --> IC movement and cell-to-cell spread
Tumbling motility
Rx: ampicillin

81

Nocardia

Aerobe
Acid fast
Pulmonary infections (IC), cutaneous infections after trauma
Rx: sulfonamides

82

Actinomyces

Anaerobe
Oral/facial abscess
Yellow sulfur granules
PID w/ IUDs
Rx: penicillin

83

Mycobacterium tuberculosis

Caseating granulomas with central necrosis and Langerhans giant cells
Cord factor --> serpentine cord --> inhibits mac maturation, induces release of TNF-alpha
Sulfatides --> inhibit phagolysosomal fusion
Acid fast (mycolic acid)
Lowenstein Jensen medium

84

Mycobacterium leprae

Cool temperatures
Armadillo reservoir
Lepromatous: low cell-mediated immunity, humoral Th2 response, numerous acid fast bacilli
Tuberculoid: high cell-mediated immunity, largely Th1-type immune response, rare acid fast bacilli
Rx: dapsone, rifampin, clofazimine

85

Utilizes maltose

N. meningitidis

86

Doesn't utilize maltose

N. gonorrhoeae
Moraxella

87

Grows in 42 C

Campylobacter jejuni

88

Grows in alkaline media

Vibrio cholerae

89

Produces urease

H. pylori

90

Fast lactose fermenter

Klebsiella
E. coli
Enterobacter