Vibrio and Similar Organisms Flashcards
Vibrio general characteristics
indole
oxidase
- most indole positive
- all oxidase pos except V. metschnikovii
Vibrio normal environment
marine water
halophilic (except V. cholerae and V. mimicus are not)
Vibrio media requirement
TCBS agar
How to distinguish V. cholerae from V. parahaemolyticus on TCBS?
- V. cholerae = yellow colonies, sucrose pos
- V. parahaemolyticus = green colonies, sucrose neg
Which Vibrio cholerae serological group causes cholera?
- O1
- rice-water stool
How are cholera infections acquired?
- under cooked seafood or contaminated drinking water
- Southeast Asia, Africa, South America
How does cholera cause disease?
Enterotoxin that alters ion transport of intestinal mucosa, leading to massive release of water -> diarrhea
Vibrio parahaemolyticus disease assocation
mild-moderate cholera-like diarrhea disease
How is Vibrio parahaemolyticus transmitted?
Raw shellfish
important cause of food poisoning in Asia
Vibrio vulnificus disease association
- Highly virulent
- Septicemia after eating undercooked seafood, esp raw oysters
- rapidly progressive wound infection after exposure to marine water
Vibrio alginolyticus
otitis media and wound infections
Aeromonas normal environment
fresh and salt water
Aeromonas disease assocation
cellulitis and diarrhea
list clinically important Aeromonas spp
- A. hydrophilia
- A. caviae
- A. veronii
A. hydrophila biochemical traits
SBA
oxidase
citrate
indole
VP
ONPG
- beta hemolytic
- oxidase pos
- citrate pos
- indole pos
- VP pos
- ONPG pos
Plesiomonas shigelloides transmitted by
eating undercooked seafood
P. shigelloides disease association
self-limiting gasteroenteritis
P. shigelloides oxidase
oxidase pos
but is still part of Enterobacteriaceae family
Campylobacter spp disease association
food poisoning
- gastroenteritis
- diarrhea
- septic arthritis
Campylobacter transmitted by
eating undercooked contaminated poultry or other meat products
Which Campylobacter spp is the most common infectious agent?
C. jejuni
C. jejuni gram stain/morphology
GN curved bacilli that may appear S-shaped or spiral
C. jejuni incubation requirements
- microaerophilic
- grows at 42°C
- slow growth at 37°C
C. jejuni biochemical traits
carb OF
oxidase
catalase
motility
- no carb oxidation or fermentation
- oxidase pos
- catalase pos
- darting motility
C. jejuni Abx resistance/susceptibility
- cephalothin resistant
- nalidixic acid sensitive
H. pylori disease association
- peptic and duodenal ulcers
- linked to stomach cancer
H. pylori biochemical traits
oxidase
rapid urease
catalase
- oxidase pos
- rapid urease pos
- catalase pos
H. pylori isolated from ___
gastric biopsy on SBA, Brucella, and Skirrow’s agars incubated microaerophilically
other methods of H. pylori detection
- fecal antigen
- urea breath test
- urease activity in stomach biopsy material