Gram Negative Rods Flashcards
Id Vibrio cholera morphology motility O2 requirement Oxidase Ph requirement salt requirement
comma shaped, curved rods motile facultative anaerobe oxidase positive basic / alkaline maybe halophilic
An antigenic structure used for serologic specificity
O lipopolysaccharide
Serotype associated with cholera
Serotype O1 & O139
Serotype O1 & O139 can produce:
choleragen (cholera toxin)
Virulence factors of v cholera (6)
adherence factors motility mucinolytic enzymes neuraminidase proteases cholera enterotoxin
T / F
Cholera enterotoxin is heat labile
T
Cholera enterotoxin is composed of 2 subunits, A & B.
What is the role of A?
catalyzes ADP ribosylation regulator complex
What is the effect of the enterotoxin?
prolonged hypersecretion of water & electrolytes
inhibits absorption of Na+ & Cl-
What is the difference of V. cholera O139 from O1
O139 has lost the characteristic O1 somatic antigen
although has retained the epidemic potential of O1 strain
What are the characteristic manifestations of cholera?
rice water stools
Washer woman’s hands
V. cholera is best cultured on
Thiosulfate Bile Salt Agar
How do you differentiate V. cholerae from V. parahemolyticus?
Cholerae is yellow
Parahemolyticus is green
T/F
Vibrio infections are not self-limiting
F
What is the mode of action of Tetracycline?
a. Interferes with protein synthesis
b. Stop stool output
c. Shortens the period of excretion of Vibrio
d. A &C
e. All of the above
D.
B. should be reduces stool output in cholera
T/F
Majority of outbreaks are caused by O1
T
