Quiz 10: Vibrio, Aeromonas, Campylobacter, and Helicobacter

The organism that causes chronic gastritis and is responsible for most peptic ulcers is

Urease positive

What is the primary mode of transmission of Helicobacter pylori in humans?

Person to person via fecal-oral

During the months of April to October, micro labs in the DelMarVa region should add this medium to screen stool specimens for enteric pathogens.

Thiosulfate citrate bile salts sucrose

This serogroup of Vibrio cholerae is the most common associated with current pandemics of cholera

O:1

Which two of these characteristics are not common to all Vibrio spp.?

a. Halophilic

b. Oxidase positive

c. Ferment glucose

d. Resistant to vibriostatic O/129

Halophilic and Resistant to vibriostatic O/129

What mechanism is responsible for “rice water stool” associated with cholera?

Hyperproduction of cAMP

Which of these results is associated with V. parahaemolyticus?

a. Growth in 0% NaCl broth

b. MAC: pink colonies

c. SBA: β-hemolytic

d. TCBS: Green colonies

c. SBA: β-hemolytic

What is a major source of enteric campylobacter disease?

Undercooked poultry

What incubation conditions are optimal to successfully isolate C. jejuni?

5% O2, 10% CO2, 85% N2 @ 42C

What treatments are recommended for GI campylobacteriosis?

Fluids and electrocytes

While swimming in a lake near his home, a young boy cut his foot and developed an infection. An isolate with large, β-hemolytic colonies on SBA and pink colonies on MAC grew from the wound aspirate. The isolate was spot indole positive. The MLS reported the isolate as E. coli. What test should have been performed to confirm the ID before reporting?

Oxidase

A 28yo female developed bloody diarrhea 48hrs after a picnic lunch of fried chicken, coleslaw, and baked beans. Her PCP submitted a stool culture. Flat, runny colonies are observed on selective media after 48hrs incubation at 42C. The isolate is catalase and oxidase positive. What additional test is best to perform for presumptive ID of this isolate?

Hippurate hydrolysis

A 45yo man is admitted in the ED in August with fever, chills, nausea, and hemorrhagic, fluid filled lesions on his left leg. The patient has a history of chronic Hep B and reported he had just returned from a Florida vacation 2 days prior. Gram smear and culture of one of the lesion revealed curved, gram-negative bacilli. Before proper treatment could be administered, the patient died. Given patient history, what organism was most likely isolated.

Vibrio vulnificus

A college student attends a beach part where raw oysters and other shellfish are consumed. The next day, he has symptoms of septicemia. The blood cultures grow gram-negative bacilli with the below characteristics:

Oxidase +, MAC: Pink colonies, O/129: S

The most likely organism is:

Vibrio vulnificus

A 38yo is hospitalized with severe diarrhea and dehydration. He reported he recently visited friends in New Orleans and they had eaten at several raw bars. The stool culture grew large, non-hemolytic colonies on SBA that are NLF on MAC and green on TCBS. The isolate has these test results.

Catalase + Indole (-)

Oxidase + Broth with 0% NaCl – NG

Broth with 2% NaCl – G

What is the most likely ID of this isolate?

Vibrio parahaemolyticus