Campylobacter & Helicobacter

Question 1

What are the general characteristics of Campylobacter spp.?

Answer 1

Nonspore forming, curved gram-negative bacilli, oxidase positive, motile, microaerophilic, nonfermentative.

Shows an “S” shaped or “seagull winged” appearance and has darting motility in wet preparations.

Question 2

What are three common species of Campylobacter?

Answer 2

• Campylobacter jejuni subsp. jejuni
• Campylobacter fetus subsp. fetus
• Campylobacter coli

Question 3

Which class do Neisseria species belong to?

Answer 3

Proteobacteria

Question 4

What is the pathogenicity of Neisseria gonorrhoeae and Neisseria meningitidis?

Answer 4

Neisseria gonorrhoeae is always pathogenic; Neisseria meningitidis can be a commensal inhabitant of the upper respiratory tract.

Question 5

What is the most common cause of bacterial gastroenteritis worldwide?

Answer 5

Campylobacter jejuni

Question 6

How does Campylobacter jejuni typically enter the human body?

Answer 6

Through dirty drinking water or undercooked meat, especially chicken.

Question 7

What are the typical symptoms of gastroenteritis caused by C. jejuni?

Answer 7

• Fever
• Abdominal pain
• Cramping
• Diarrhea (may contain blood or pus)

Question 8

What is the incubation period for symptoms after ingesting contaminated food or drink containing C. jejuni?

Answer 8

2-10 days

Question 9

What is the typical Gram stain morphology of C. jejuni?

Answer 9

Curved Gram-negative rod with a ‘seagull’ winged appearance.

Question 10

What is the optimal temperature for growing thermophilic Campylobacter spp.?

Answer 10

42ºC

Question 11

What media is used for Campylobacter culture?

Answer 11

• Campy BAP
• Modified Skirrow Media
• Campylobacter Medium (Karmali)

Question 12

What type of environment is required for culturing Campylobacter organisms?

Answer 12

Microaerophilic environment with a gas mixture of 5-10% O2, 10% CO2, and 80-85% N2.

Question 13

What is suggested by the presence of blood or pus in stools caused by C. jejuni?

Answer 13

An invasive mechanism, as C. jejuni produces exotoxins with cytolytic activity.

Question 14

True or False: C. jejuni infection is usually self-limiting.

Answer 14

True

Question 15

Fill in the blank: The Gram staining results for C. jejuni are better when _______ is used instead of safranin.

Answer 15

carbolfuchsin

Question 16

What is the maximum time after stool passage that fresh specimens should be used for culture of Campylobacter spp.?

Answer 16

Less than 2 hours

Question 17

What is the appearance of C. jejuni colonies on blood agar?

Answer 17

Red under colonies due to production of cytochromes.

Question 18

What are the components of Campy BAP used in Campylobacter culture?

Answer 18

• Brucella blood agar base
• 10% sheep blood
• Vancomycin
• Trimethoprim
• Polymyxin B
• Amphotericin B
• Cephalothin

Question 19

What is the incubation time and temperature for culturing C. fetus?

Answer 19

Incubated at 37ºC under microaerophilic conditions for at least 72 hours.

Question 20

What are common methods to create a microaerophilic environment for Campylobacter culture?

Answer 20

• Campy Gas Packs
• Evacuation-Replacement
• BIOBAG
• Buddy Bags

Question 21

Which class do Alysiella, CDC EF 4a and b, Acinetobacter, and Moraxella species belong to?

Answer 21

Proteobacteria

Question 22

What is the morphology and biochemistry of Moraxella catarrhalis similar to?

Answer 22

Neisseria species

Question 23

Is Neisseria gonorrheae always pathogenic or commensal?

Answer 23

Always pathogenic

Question 24

Can Neisseria meningitidis be a commensal inhabitant?

Answer 24

Yes, in the upper respiratory tract of carriers

Question 25

What is the colonial morphology of Campylobacter jejuni?

Answer 25

Moist, 'runny-looking', spreading, nonhemolytic colonies

Question 26

What are some characteristics of suspicious colonies of Campylobacter spp. for presumptive identification?

Answer 26

* Catalase positive * Oxidase positive * Nitrate positive * Darting motility * Curved Gram-negative bacilli

Question 27

What is the treatment for intestinal campylobacteriosis?

Answer 27

Erythromycin

Question 28

What are the general characteristics of Helicobacter spp.?

Answer 28

* Gram-negative * Microaerophilic * Motile * Catalase positive * Oxidase positive

Question 29

What is the leading cause of peptic ulcers and chronic gastritis?

Answer 29

H. pylori

Question 30

What is the clinical picture associated with H. pylori infection?

Answer 30

* Low grade inflammatory process * Chronic superficial gastritis * Major cause of ulcers * Risk factor for gastric carcinoma

Question 31

What type of specimens are used for the culture of H. pylori?

Answer 31

Gastric biopsies

Question 32

What does the Gram stain of a homogenized biopsy of H. pylori show?

Answer 32

Small, curved Gram-negative bacilli

Question 33

What media is used for recovering H. pylori?

Answer 33

* Chocolate agar * Selective medium such as Skirrow

Question 34

What are the characteristics for presumptive identification of H. pylori?

Answer 34

* Small colonies growing microaerophilically * Curved Gram-negative bacilli * Catalase positive * Oxidase positive * Positive rapid urease test

Question 35

What is the rapid urea breath test used for?

Answer 35

Detecting the presence of H. pylori

Question 36

What is a noninvasive procedure for detecting H. pylori?

Answer 36

Rapid urea breath test

Question 37

What tests can detect serum antibodies to H. pylori?

Answer 37

* ELISA * Indirect immunofluorescent assay (IFA)

Question 38

What biochemical tests can differentiate Campylobacter and Helicobacter species?

Answer 38

Catalase, Nitrate, Urease, Hippurate, Hydrolysis, Growth at 42ºC, Nalidixic Acid, Cephalothin

Question 39

Which Campylobacter species is sensitive to nalidixic acid?

Answer 39

C. jejuni and C. coli

Question 40

Which Helicobacter species is resistant to cephalothin?

Answer 40

H. pylori