Exam 3: E. coli Enteric Diseases Flashcards
What is the host association for F4?
Swine ETEC
What is the host association for F5?
Cattle, sheep, and swine ETEC
What is the host association for F6?
Almost always association with swine ETEC, sometimes cattle
What is the host association for F18?
It is now a common fimbrial adhesion associated with swine ETEC
What is F18ab primarily associated with?
Edema disease strains
What is F18ac primarily associated with?
ETEC
What is the host association for F41?
Usually with cattle, sometimes swine
What does diarrhea result from?
Action of enterotoxins
What is LT involved with?
The swine type of E. coli
What is LT?
Heat-labile
A large protein made up of A and B subunits
What is the general mechanism of LT?
It causes disregulation of adenylate cyclase, which causes overproduction of cAMP
What is LT1?
Plasmid encoded and neutralized by anti-cholera toxin antibodies
What is LT2?
Chromosomoally encoded and not neutralized by anti-cholera toxin antibodies
What is heat stable (ST)?
A family of low MW proteins with a lipoprotein binding portion
What does STa do?
Activates guanylate cyclase and causes overproduction of cGMP
What does STb do?
Stimulates a GTP-binding regulatory protein
What is produced with porcine ETEC?
STa and/or STb
What is produced with bovine ETEC?
STa
Describe EAEC
Associated with disease and can cause watery diarrhea
What do some EAEC express?
EAST1 toxin
What can E. coli expressing EAST1 or AAF be isolated from?
Weaned pigs with diarrhea and calves with diarrhea
What does human EPEC express?
Fimbriae called bundle forming pili
What is intimate adherence caused by in EPEC?
Intimin
What does EPEC have?
Type III secretion system
What is one of the injected proteins in EPEC?
Tir
What do tir and other injected proteins do in EPEC?
Reorganize the actin cytoskeleton in enterocytes to form attaching and effacing lesions
What is EPEC a major cause of in young rabbits?
Diarrhea
What is the target of shiga toxin?
Endothelial cells
What does shiga toxin do to endothelial cells?
Shuts down protein translation/synthesis
What does EHEC/STEC?
Shiga toxin, unlike EPEC
Describe the shiga toxin Stx2e
Associated with edema disease in swine
Which E. coli use T3SS as the mechanism of producing disease?
Enteropathogenic and enterohemorrhagic