Enteric Bacteria vibrios (3) Flashcards
Bacteriology of Vibrios
curved gram negative rod
What agar is good for culturing vibrios?
bile salts agar - selective for salt tolerance
What vibrio has a moderately effective vaccine available?
Cholera
What are the reservoirs for cholera?
humans and ocean microbial communities
-indian ocean and gulf of mexico
Cholera has two lifestyle forms, what are they and which one is a source of genetic diversity?
planktonic and pathogenic
plank tonic is source of diversity
How is cholera transmitted?
fecal oral transmission
Where does cholera colonize? How?
colonizes lumen epithelium of small bowel with mucinase and toxin-coregulated pillus - TCP
Are alot of cholera bacteria needed to infect someone?
yes - high infectious dose
How does cholera create the massive diarrhea it is notorious for? What is the name of this?
choleragen exotoxin
AB signal transduction: A causes persistent activation of adenylate cyclase–> loss of water and ions
“rice water stool”
Who is particularly susceptible to a cholera infection?
people on antacids or with gastrectomy
-stomach acid usually kills bacteria
How does the cholera bacteria acquire the choleragen gene?
lysogenic bacteriophage CTX
What are markers for the presence of CTX?
O1 and O139
What is the usual cause of death from cholera?
dehydration and electrolyte imbalance - Acidosis and loss of potassium
How would you diagnose and treat dehydration?
skin tenting pinching
treat: IV lacted Ringer solution
NOT just saline- acidosis
What antibiotic is available to help shorten the course of cholera? What other vibiro is it effective for?
doxycycline
-parahaemolyticus
What are the non-cholera vibrio infections? what are they associated with?
parahaemolyticus, vulcanis
- self limited gastroenteritis
- rapid progression cellulitis
What is a notorious career that is associated with non-cholera vibrio infection?
working with raw shellfish
What is the reservoir for parahaemolyticus and vulcanis
ocean water
they are halophiles - live in high salt
What are important co-morbid conditions associated with a poor prognosis for infeciton with parahaemolyticus and vulcanis?
liver or renal disease
immunodeficiency
iron overload
What is the typical appearance of cellulitis caused by the non-cholera vibrios?
hemorrhagic bullae
How do you treat the cellulitis caused by non-cholera vibrios?
RAPID and aggressive surgery
Are systemic symptoms present in cholera infection
usually not, pediatrics it can be since their gut is so thin
What is similar about infection with cholera and non-cholera vibirios?
- possibility of dehydration
- self limited course
- efficacy of doxycycline treatment
- site of infection
What is not similar about infection with cholera and non-cholera vibrios?
likelihood of dehydration and need for antibiotic
V vulnificus is similar to gas gangrene in that it produces what virulence factor?
protease exotoxins
