Toxin-producing bacterial pathogens Flashcards
what are the 3 mechanisms that pathogens can cause infection
invasive
toxin-producing
hybrids of the two above
what is the most common toxin producing pathogen species
Vibrio
of the 4 subspecies of Vibrio, what toxin producing pathogen causes the most severe disease
vibrio cholerae
what is the El tor strain, and what made it different from the previous strains
A new strain of vibrio cholera that was pandemic
-mutated the O1 antigen, new LPS serotype, encapsulated
what are the virulence factors of vibrio cholerae
flagella, pili to adhere and pili is phage encoded, meaning once the pili is expressed, the cholera toxin is phage encoded
how does the phage encoded cholera toxin affect hosts
- toxin binds to receptor activating G protein
- activates adenylate cyclase
- constant increase cAMP which stops adsorbtion of Na
- excrete Cl and get watery diarhea
what are the 2 pathogens that cause secretory diarhea (watery stool)
Vibrio and ETEC (enterotoxigenic e-coli)
what is the main pathogen that causes traveler’s diarhea
ETEC (enterotoxigenic ecoli)
what 2 toxins does ETEC produce that causes travelers diarhea
Heat-labile toxin (LT)
Heat-stable toxin (ST)
What is the difference b/w heat-labile toxin (LT) and heat-stable toxin (ST)
LT - works exactly like vibrio in that it activates adenylate cyclase resulting in secretory diarhea
ST - activates guanylate cyclase which induces cGMP causing epithelial cells to stop adsorbing Na resulting in watery stool
What are the steps to identifying which pathogen is causing secretory diarhea ?
Step 1 - rule out Vibrio cholerea
2 - inoculate plates with shit samples then
3 - grow
what animal is vibrio cholerae found in
seawater shellfish
how do you treat secretory diarhea
- ORAL rehydration
- *CANT DO IV **
- antibiotics
what two pathogens are know as “hybrid” misfits
EPEC (enteropathogeninc E-coli)
EHEC (Enterohemorrhagic E-coli)
how do EPEC and EHEC ahere to GI tissue
Intimate Adherance