Flashcards in VirGeneReg2 Deck (8)
What is the causative agent in cholera?
-highly motile, uni-flagellated and gram negative curved rod
How does v. cholerae cause disease?
-survive passage through gastric acid of stomach
-colonize in the upper small intestine
-produce and excrete exotoxin
-disseminate in a watery diarrhea
What is the main virulence factor of cholera?
How does the cholera toxin on the CTX phage work?
1. CtxA and CtxB
2. B coats A and cleaves it to A1 and A2
3. binds host GM1 receptor and A1 subunit enters host membrane
4. A1 subunit modifies ADP-ribosylation a GTP binding protein
5. modified G-protein activates adenylate cyclase
6. cAMP activates PKA
7. PKA activates transporters causing efflux of ions and water ie. diarrhea
Are motility genes on during colonization?
no only on to reach site of colonization and then toxigenic genes turned on
What is TCP? What is ACF?
toxin colonizing pilus
accessory colonizing factors
-mutations to tcp or acf reduce colonization
-located on large pathogenicity island called TCP-ACF element
Activation of what regulon permits the synthesis of virulence factors?
-ToxR is the regulator