Enterobacteriaceae PART2 Flashcards
Habitat and most common infection involving E. coli
- Large bowel (#1)
- Urinary Tract Infection (#1 most common cause), gastroenteritis
Habitat and most common infection involving Shigella
- NOT normal flora (#1) / always pathogenic
- penetrate epithelial cells of intestinal mucosa (blood, mucous, leukocytes)
Habitat and most common infection involving Salmonella
- NOT normal flora (#2)
- Gastroenteritis (animals) and Septicemia
Habitat and most common infection involving Klebsiella pneumoniae
- Bowel (#2)
- pneumonia (“current-jelly”) and nosocomial infections
Habitat and most common infection involving Citrobacter
- GI?
- variety of infections, primarily urinary tract infections
Habitat and most common infection involving Serratia
- GI, also respiratory flora
- Formerly strictly saprophytic now major nosocomial problem
Habitat and most common infection involving Enterobacter
- GI?
- Variety of infections, esp. UTI
Habitat and most common infection involving Proteus and Morganella
- GI?
- UTI…triple phosphate (struvite) crystals, renal stones
Habitat and most common infection involving Yersinia
- Bubonic (lymph), pneumonic (lungs), septicemic (blood)
- Agent of the plague
Major source of infection for Enterohemorrhagic E. coli causing gastroenteritis
Hamburger, fruits, vegetables, water(pools), etc
Major source of infection for Salmonella causing gastroenteritis
Animals (chicken, turtles, iguanas ect), food, water
Major source of infection for causing gastroenteritis
?
Major source of infection for causing gastroenteritis
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Major source of infection for Yersinia pestis
- endemic in rodents and transmitted by insect vector, domestic cats to humans
Factors contributing to pathogenicity of EPEC and disease caused
Enteropathogenic E. coli
- due to organism’s ability to adhere to cells in small intestine
- Infant diarrhea
Factors contributing to pathogenicity of ETEC and disease caused
Enterotoxigenic E. coli
- due to toxins (Heat labile toxin and Heat stable toxin)
- Traveler’s Diarrhea (Montezuma’s Revenge)
Factors contributing to pathogenicity of EIEC and disease caused
Enteroinvasive E. coli
- due to ability to invade into cucosal cells of intestine not through to blood
- Similar to Shigella (no specific disease caused)
Factors contributing to pathogenicity of STEC, EHEC, VTEC and disease caused
Shiga Toxin, Enterohemorrhagic E. coli, Verotoxin
- due to cytotoxins (verotoxins, and “shiga-like” toxins)
- Leading cause of acute renal failure in children
Formulate an approach for isolating/ identifying E. coli (O157:H7) in stool cultures
- media?
- biochemical recommendations?
- typing recommendations?
(not sure of this answer but I think its important to know??)
- use sorbitol MacConkey Agar (will be sorbitol neg)
- run a MUG tes (will be MUG neg)
Applications and advantages of shiga toxin testing on stool specimens
- some sorbitol positive STEC strains identified (would be missed by culture)
- assay will detect serotypes other than O157
Compare and contrast the pathogenic mechanism involved in E. coli, Shigella, and Salmonellas gastroenteritis
Typhoid Fever
- recommended type of specimen
- characteristics of the disease
- specific characteristics for identification of pathogens
- test positive in blood cultures
- Man only host, invasive, high fever, carriers harbor in gallbladder
- Serotyping required for identification: it is positive with Vi and group D antisera (may have to boil to get rxn with group D antisera)
most common enteric agent of infection
- Urinary tract
E. coli
most common enteric agent of infection
-abdominal wound
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