Vibrio and Similar Organisms

Question 1

Vibrio general characteristics
indole
oxidase

Answer 1

• most indole positive
• all oxidase pos except V. metschnikovii

Question 2

Vibrio normal environment

Answer 2

marine water
halophilic (except V. cholerae and V. mimicus are not)

Question 3

Vibrio media requirement

Answer 3

TCBS agar

Question 4

How to distinguish V. cholerae from V. parahaemolyticus on TCBS?

Answer 4

• V. cholerae = yellow colonies, sucrose pos
• V. parahaemolyticus = green colonies, sucrose neg

Question 5

Which Vibrio cholerae serological group causes cholera?

Answer 5

• O1
• rice-water stool

Question 6

How are cholera infections acquired?

Answer 6

• under cooked seafood or contaminated drinking water
• Southeast Asia, Africa, South America

Question 7

How does cholera cause disease?

Answer 7

Enterotoxin that alters ion transport of intestinal mucosa, leading to massive release of water -> diarrhea

Question 8

Vibrio parahaemolyticus disease assocation

Answer 8

mild-moderate cholera-like diarrhea disease

Question 9

How is Vibrio parahaemolyticus transmitted?

Answer 9

Raw shellfish
important cause of food poisoning in Asia

Question 10

Vibrio vulnificus disease association

Answer 10

• Highly virulent
• Septicemia after eating undercooked seafood, esp raw oysters
• rapidly progressive wound infection after exposure to marine water

Question 11

Vibrio alginolyticus

Answer 11

otitis media and wound infections

Question 12

Aeromonas normal environment

Answer 12

fresh and salt water

Question 13

Aeromonas disease assocation

Answer 13

cellulitis and diarrhea

Question 14

list clinically important Aeromonas spp

Answer 14

• A. hydrophilia
• A. caviae
• A. veronii

Question 15

A. hydrophila biochemical traits
SBA
oxidase
citrate
indole
VP
ONPG

Answer 15

• beta hemolytic
• oxidase pos
• citrate pos
• indole pos
• VP pos
• ONPG pos

Question 16

Plesiomonas shigelloides transmitted by

Answer 16

eating undercooked seafood

Question 17

P. shigelloides disease association

Answer 17

self-limiting gasteroenteritis

Question 18

P. shigelloides oxidase

Answer 18

oxidase pos
but is still part of Enterobacteriaceae family

Question 19

Campylobacter spp disease association

Answer 19

food poisoning
- gastroenteritis
- diarrhea
- septic arthritis

Question 20

Campylobacter transmitted by

Answer 20

eating undercooked contaminated poultry or other meat products

Question 21

Which Campylobacter spp is the most common infectious agent?

Answer 21

C. jejuni

Question 22

C. jejuni gram stain/morphology

Answer 22

GN curved bacilli that may appear S-shaped or spiral

Question 23

C. jejuni incubation requirements

Answer 23

• microaerophilic
• grows at 42°C
• slow growth at 37°C

Question 24

C. jejuni biochemical traits
carb OF
oxidase
catalase
motility

Answer 24

• no carb oxidation or fermentation
• oxidase pos
• catalase pos
• darting motility

Question 25

C. jejuni Abx resistance/susceptibility

Answer 25

• cephalothin resistant
• nalidixic acid sensitive

Question 26

H. pylori disease association

Answer 26

• peptic and duodenal ulcers
• linked to stomach cancer

Question 27

H. pylori biochemical traits
oxidase
rapid urease
catalase

Answer 27

• oxidase pos
• rapid urease pos
• catalase pos

Question 28

H. pylori isolated from ___

Answer 28

gastric biopsy on SBA, Brucella, and Skirrow’s agars incubated microaerophilically

Question 29

other methods of H. pylori detection

Answer 29

• fecal antigen
• urea breath test
• urease activity in stomach biopsy material