Gram Negative Pathogens Part 2 (Enterics cont) Flashcards
What virulence factors allow Enteropathogenic E. coli (EPEC) to produce watery diarrhea?
Enteroaggregative Fimbriae (EAF) pilus allowing tight adherence
What kind of diarrhea does EPEC produce?
Watery diarrhea with:
Vomiting
Fever in infants
Diarrhea in infants is most likely linked with what kind of E. coli?
Enteropathogenic E. coli
What virulence factors allow Enterotoxigenic E. coli (ETEC) to produce watery diarrhea?
Colonization Factor A (CFA) pilus
LT and/or ST exotoxin
What kind of E. coli usually produces Traveler’s diarrhea (Montezuma’s revenge)?
Enterotoxigenic E. coli
What kind of E. coli usually produces diarrhea in children aged 5 years old and below?
Enterotoxigenic E. coli
What kind of diarrhea does ETEC produce?
Watery diarrhea
What virulence factors allow Enterohemorrhagic E. coli (EHEC) to produce bloody diarrhea?
CFA pilus
Capsule
Shiga-like toxin (verotoxin) (cytotoxic effects on host cells)
What type of diarrhea does EHEC produce?
Bloody diarrhea (hemorrhagic colitis) without fever or pus; may be associated with hemolytic uremic syndrome (hemolytic anemia, acute kidney injury, and thrombocytopenia)
This kind of bloody diarrhea has been linked to infected meat products prompting suspicion for cattle reservoir.
EHEC induced bloody diarrhea
What virulence factors allow Enteroinvasive E. coli (EIEC) to produce bloody diarrhea?
Small amount of Shiga toxin allowing invasion of the intestinal mucosal epithelial cells
What type of diarrhea does EIEC produce?
Bloody diarrhea with pus and WBC in stool; associated with fever
This type of E. coli produces bloody diarrhea with pus and WBC in stool which may be associated with fever.
Enteroinvasive E. coli
This type of E. coli produces blood diarrhea without fever or pus and may be associated with hemolytic uremic syndrome.
Enterohemorrhagic E. coli
This type of diarrhea is common in children in developing countries.
Enteroinvasive E. coli (EIEC) - induced bloody diarrhea
This type of E. coli produces acute or chronic diarrhea (>14 days)
Enteroaggregative E. coli
What virulence factors allow Enteroaggregative E. coli (EAEC) to produce bloody diarrhea?
Exotoxin (ST), enterotoxin, and hemolysin
This type of E. coli usually causes food borne diarrhea in developed countries and causes the cases of diarrhea developing countries.
Enteroaggregative E coli.
T/F. Shigella dysenteriae appears as slender rods in young cultures and cocco-bacillus when mature.
False. Slender rods when mature; cocco-bacillus when young
T/F. Shigella dysenteriae may be aerobes or facultative anaerobe.
True.
T/F. Shigella dysenteriae can ferment glucose.
True.
T/F. Shigella dysenteriae can ferment lactose.
False. Cannot ferment lactose
T/F. Shigella dysenteriae can produce hydrogen sulfide.
False. Cannot produce hydrogen sulfide
T/F. Shigella dysenteriae can produce gas but rarely.
True
T/F. Shigella dysenteriae has A/K/G+-/HS-
True. Can ferment glucose but not fructose, some produces gas, but cannot produce hydrogen sulfide
What are the virulence factors associated with Shigella dysenteriae?
Low infectious dose
Shiga toxin
This microorganism has a very low infectious dose at just 10^2 cells.
Shigella dysenteriae
What type of diarrhea does Shigella dysenteriae produce?
Bloody diarrhea with mucus and pus production associated with fever and abdominal pain.
Treatment for Shigella dysenteriae infection
No anti-diarrheal drugs (treatment limited to fluid replacement therapy)
Oral fluid replacement
IV fluid
Antibiotics for severe infections
T/F. Salmonella are often commensal but can be pathogenic.
True
What are the three presentation of Salmonella infection?
enteritis, enteric fever, and systemic infections
Transmission of Salmonella is primarily via:
contaminated water and contaminated food or animal products
T/F. Salmonella appears rod shaped.
True.
T/F. Salmonella is anaerobic bacterium.
False. Facultative anaerobic bacterium.