Bugs Flashcards
(37 cards)
Strep pneumo
Gram + cocci, alpha hemolytic, lancet shape, encapsulated
Sinusitis, otitis, CA meningitis, endocarditis,
Tx: ceftriaxone
Haemophilus influenza
Nontypeable
Type B
Nontypeable-Gram - cocci, fastidious(complicated nutrient requirements)
Type b- gram - rod, b ag capsule, chocolate agar, children!
Sinusitis, otitis, meningitis (infants and children up to 24 mo)
IgG Vaccines to type B (opsonization via type b carb ag)
non-typeable causes post-vaccination infections (above)
Moraxella catarrhalis
Gram - diplococci, cultureable
Sinusitis, OM
Newborn meningitis
GBS: Gram + coccus, carbohydrate capsule, has C5a peptidase
E.Coli K1: gram - rod, polysaccharide adid capsule
Listeria monocytogenes: gram + rod nonspore, intracell m@ (immunocrompromised meningitis from fridge foods)
Nisseria meningitis
Gram - diplococci, encapsulated, ag group polysalic acid
Grow on chocolate agar and thoyer-Morton plates– culturable
CA meningitis
Staph aureus
Gram +, clusters, coagulase and catalase +
Endocarditis- preformed toxin; human only
Necrotizing fasciitis
impetigo
food poisoning from preformed toxin, no AB given
Strep viridans
Gram + chains, alpha hemolytic
Endocarditis on previously damaged valves, low virulence
UTI
E.coli
Klebsiella
Proteus
Tx: cephalaxin
Lyme disease
Burrelia bergdurten: gram- spirochete, infects endothelium; NE US
Bulls eye lesion at bite site, flu-like symptoms, then severe fatigue, arthritis, neurological involvement: stiff neck, palsy, visual and headache
Rickettsia rickettsi
Gram - cocci
Rocky Mountain spotted fever: rash on hands from Appalachian mnt area
cannot be cultured in cell free media
Bubonic plague –> pneumonic plague
Rabbit fever
Yersinia pestis: gram - rod- bipolar staining;
(fleas {swollen LN, fever, septic shock}–> person-person{ bloody sputum rapid death});
Francisella tularensis: gram - rod; influenza symptoms (ingestion), ulcer (skin), sepsis ( inhalation)
Clostridium botulinum
Gram + rod, spore forming, neurotoxin (A-B toxin, heat labile protease–> flaccid paralysis, inhib acetylcholine)
Paralysis from canned foods, diarrhea
Bacillus cereus
Gram + rod, spore forming
Rice bug, preformed enterotoxin ingested,
Shigella dysenterae
Gram - nonmotile rod, lac -, T3SS, intracellular
Low infectious dose ~ 10 microbes (dysenterae)
Shiga toxin: deglycosylates rRNA (–| protein synthesis), actin polymerization
Nonendemic in US, humans only{dysenterae},
sissonei (us water, spread cell-cell), flexneri (water/blood US)
E.Coli O157:H7
EHEC
Infectious dose: 10-50 microbes , from processed meats; acid resistance, sorbitol neg- clear on mackonkey
phage encoded Shiga toxin releases Gb3 ( receptor on kidney)
Bloody diarrhea after watery diarrhea
tx: antitoxin before or during AB tx
AE lesions, HUS children,
Salmonella typhi
Typhoid
S. typhi: humans only, systemic infection, dysenteric/diarrhea
LPS, CMI, Vi capsule
Vibrio cholera
Gram- rod curved
Secretory, small bowel, WATERY diarrhea
Cholera toxin- phage encoded, AB type, activates Adenylate Cyclase and cAMP
V. Parahemolyticus
Japan seafood,
Hemolysin
Vomiting, watey diarrhea
General E.Coli
Gram - bacillus Lac pos (beware not all of them!)
ETEC
LT/ST heat labile toxin, LT: AB toxin, GMI?, protective AB, adenylate cyclase
ST: gives no cell damage, inc cGMP
Travelers diarrhea, watery, small bowel
EAEC
Persistent diarrhea, colon, toxins?
AIDS pt
EIEC
Dysentery, invades and spreads
Costridium perfringes
Gram + spore forming
Gas gangrene and diarrhea (HL toxin)
Clostridium difficile
Gram + rod, spore forming, drug resistant, normal flora
2 toxins,
Pseudomembranous colitis, watery diarrhea progressing to bloody
Pcr to check for toxin