Chapter 20: Vibrio, Aeromonas, Plesiomonas, and Campylobacter Species Flashcards
What causes cholera
Vibrio cholera
Symptoms of cholera
Rice water stools
Large loss of water 10 to 30 movements per day
Dehydration and hypovolemic shock
Toxins causes diarrhea
General characteristics of cholera
➢Pleomorphic shapes
•Oxidase +
•Reduce nitrate to nitrite
➢Except V. metschnikovii
What stimulates the growth of most or all vibrio species
Sodium ions
What is the name of the antimicrobial disk that vibrio is susceptible to
Vibriostat disk
List two methods by which vibrios can be distinguished from aeromonads
-Vibriostat disk
-6.5% salt broth
Most Vibrio are halophiles, T/F and which two are not?
True
1) V. Cholerae and
2) V. mimicus
Name a test for the vibrio
Positive string test
What are the two most important Vibrio species.
V. cholerae and V. parahaemolyticus
Gram stain reaction of Vibrio, Aeromonas, and Plesiomonas
Gram negative
Oxidase reactivity of Vibrio, Aeromonas, and Plesiomonas
Oxidase positive
Antigenic structure of V. cholerae and V. parahaemolyticus
flagellar H antigen (not useful) and a somatic O antigen of V. cholera
How many sero-groups of Vibrio are there and which is most important?
Six. O1 are most important
O1 vibrio subtypes
. Ogawa (A, B)
•Inaba (A, C)
•Hikojima (A, B, C)
The six serogroups can be classified as 01 and non-01? T/F
True. Non-O1 generally produces milder disease and no cholera toxin
V. cholera colonized the
Small intestine where they release toxins
Cholera toxin is called and causes what symptom
choleragen,diarrhea
Treatment for V. cholera
➢IV and oral fluids containing electrolytes
➢Antibiotics to reduce organisms
V. parahaemolyticus facts
“Summer diarrhea” of Japan
Limited to areas with 1%-8% NaCl
➢Association with seafood
•Especially raw oysters
Symptoms of V. parahaemolyticus
Develop after 24-48 hours after eating contaminated seafood
•Watery diarrhea and cramping
•Sometimes vomiting
•Usually no fever
Virulence factors of V. parahaemolyticus
Heat-stabile hemolysin (Kanagawa phenomenon)
➢Using a high salt mannitol media containing erythrocytes
•Shows hemolysis
Are V. parahaemolyticus urease positive
Yes!
Where is V. vulnificus found
the Atlantic, Gulf, and Pacific coasts
V. vulnificus is also known as
lactose positive vibrio
How do you get V. vulnificus
Acquire infection from raw or undercooked seafood
V. vulnificus FACTS
Develop septicemia
•Particularly in people with increased serum iron
➢Occasionally found in wounds
Least pathogenic of the Vibrio spp.
V. alginolyticus (rarely isolated)
Which anatomical site does V. alginolyticus normally infect and who are most at risk?
Mostly external sites
➢Ear infection, wounds, or burns
Sailors or those in constant contact with seawater
Most important vibrio spp. are
Cholera and parahaemolyticus
If clinical history indicate vibrios, what plate should you culture on and what are the results?
Use TCBS (Thiosulfate, citrate, bile salts, sucrose)
Results:
Yellow- V. cholerae, V. alginolyticus
Green- V. parahaemolyticus, most V. vulnificus
Which culture plate works best for growing vibrio and why?
BAP works well since it contains enough salt for most vibrios
How do most vibrio behave on MAC agars?
LACTOSE NEGATIVE (non fermenter)
***MacConkey agar is a selective and differential culture medium for bacteria. It is designed to selectively isolate Gram-negative and enteric bacteria and differentiate them based on lactose fermentation. Lactose fermenters turn red or pink on MacConkey agar, and nonfermenters do not change color