The Vibrios Flashcards
Classify the vibrios enteric bacteria?
Curved, gram negative rods
Do the vibrios enteric bacteria grow on bile salts agar in vitro?
Yes, they do
Cholera is known for causing epidemics and pandemics throughout history- What’s the best way to prevent against cholera infection?
Hygiene- purify food and water. There is also a modestly effective vaccine for epidemics.
What are the reservoirs for cholera?
Humans and ocean microbial communities
What bodies of water are the main source of cholera reservoirs?
Indian Ocean and Gulf of Mexico
What form is the source of genetic diversity for cholera?
“Planktonic” ocean form
How is cholera transmitted?
Fecal-oral route
Cholera: High or low infectious dose?
High Infectious Dose
What two virulence factors help cholera to colonize the small intestine?
Mucinase and toxin-coregulated pilus
Does cholera secrete an enterotoxin?
Yes, choleragen- similar to toxin secreted by ETEC(noninvasive E. coli)
What is the role of cholera’s AB subunit?
It’s a signal transduction alterer
What kind of diarrhea does cholera cause?
Massive watery diarrhea-> Rice Water Stool (both intercellular and interstitial)
The choleragen gene is carried by what?
The lysogenic bacteriophage CTX
What are O1 and O139?
Markers of infection by lysogenic bacteriophage CTX
Do non-CTX V. cholerae strains cause disease?
They cause sporadic, mild disease
Is bacteremia commonly seen or rarely seen with cholera infection?
Rarely seen (Remember it’s non-invasive)
What is the most common cause of morbidity and mortality from cholera infection?
Dehydration and electrolyte imbalance (acidosis, loss of potassium)
How do you diagnose interstitial dehydration?
Skin-tenting pinch test
How do you treat dehydration resulting from cholera infection?
IV Lactated Ringers Solution (not just saline–>acidosis)
What drug helps shorten the course of v. cholerae or v. parahaemolyticus?
Doxycycline, rehydration is also important
Non-cholera vibrios (v. parahaemolyticus and v. vulcanis) are associated with what conditions?
Gastroenteritis and rapidly progressing cellulitis
What causes infection of the non-cholera vibrios (v. parahaemolyticus and v. vulcanis)?
Eating or handling raw shellfish
What is the reservoir for non-cholera vibrios (v. parahaemolyticus and v. vulcanis)?
Ocean water, they’re halophiles
What are factors that predispose you to complications after infection by non-cholera vibrios (v. parahaemolyticus and v. vulcanis)?
Liver disease, immunodeficiency, iron overload
How do you diagnose cellulitis?
Exam (rapid progression, hemorrhagic bullae, sea-water exposed injury), Gram stain, and Culture
How do you treat cellulitis caused by the non-cholera vibrios (v. parahaemolyticus and v. vulcanis)?
Dual antibiotics and surgical care
