32 CAMPYLOBACTER AND HELICOBACTER

Question 1

What is unusual about campylobacter and helicobater in terms of fermentation and oxidation?

Answer 1

• They can’t do both to carbohydrates

Question 2

What type of shape do Campylobacter have and what type of G staining?

Answer 2

• Comma-shaped or S-shaped, gram negative rods with polar flagellum.

Question 3

What is necessary for growing campylobacter in culture?

Answer 3

• Require microaerobic atmostphere: decreased oxygen with increased hydrogen and CO2.

Question 4

What are medically relevant strains of campylobacter? (4)

Answer 4

• C. jejuni, C. coli, C. upsaliensis, C. fetus.

Question 5

In what temperature does C. jejuni grows best?

Answer 5

• 42 degrees C.

Question 6

Which 2 strains of Campylobacter are linked with Guillain-Barre syndrome?

Answer 6

• C. jejuni, C. upsaliensis

Question 7

What is different about C. fetus from other campylobacter in terms of immunity and why?

Answer 7

• Resistant to complement and antibody-mediated serum killing when other C. would be killed. It has a capsule-like protein (S-protein) that is heat-stable that inhibits the C3b bing to the bacteria.

Question 8

What is the natural reservoir for campylobacter?

Answer 8

• Its zoonotic, related to consumption of tainted poultry, milk, cattle, sheep, dogs, cats, food or water.

Question 9

What do infections with C. jejuni, C. coli and C. upsaliensis cause in clinical manifestations?

Answer 9

• Gastrointestinal infections: acute enteritis (diarrhea (maybe be bloody), fever, abdominal pain mimicking acute appendicitis and bacterimia. Guilliain-Barre syndrome and reactive arthritis.

Question 10

How does C. fetus differ from other campylobacter in terms of clinical diseases?

Answer 10

• Causes intravascular (septicemia, endocarditis, septic thrombophlebitis) and extravascular (meningoencephalitis, abscesses) infections.

Question 11

What is the treatment for Campylobacter infections?

Answer 11

• Gastroenteritis: typically sel-limited; fluid and electrolyte replacement, erythromycin or azithromycin in severe cases.

Question 12

What does the structure of a Helicobacter look like? Gram stain? Catalase and oxidase?

Answer 12

• Curved or spiral w/ polar flagellum, G (-) rods, produce high levels of urase. Catalase and oxidase positive.

Question 13

What are the diseases that Helicobacter pylori cause?

Answer 13

• A gastric helicobacter, it’s been associated with gastritis, peptic ulcer, gastric adenocarnoma, and gastric mucosa-associated lymphoid tissue (MALT) B-cell lymphomas

Question 14

What is unusual about helicobacter in terms of fementation?

Answer 14

• They cannot oxidize or ferment carbohydrates.

Question 15

What is the mechanism of H. pylori colonization?

Answer 15

• 1) Blockage of acid production by a bacterial acid-inhibitory protein.
• 2) neutralization of gastric acids by the ammonia produced by bacterial urease activity.
• 3) The highly motile H. pylori pass thru the mucus and adhere to the gastric epithelial cells.
  What type of secretion system do H. pylori have to affect neighboring epithelial cells?
• Type IV secretion system.

Question 16

What does PAI (phosphoribosylanthranilate isomerase) from H. pylori cause?

Answer 16

• Induces inerleukin-8 (IL-8) production, which attracts neutrophils. Release of proteases and reactive oxygen molecules by the neutrophils is believed to contribute to gastritis and gastric ulcers.

Question 17

What is the primary reservoir for H. pylori and how does it spread?

Answer 17

• Humans; fecal-oral route.

Question 18

What is the benefit of H. pylori colonization?

Answer 18

• Protection from gastroesophageal reflux disease and adenocarcinomas of the lower esophagus and gastric cardia.

Question 19

Which type of strain is the gold standard for detecting H. pylori?

Answer 19

• Warthin-Starry silver stain.

Question 20

What is the treatment for H. pylori?

Answer 20

• Proton pump inhibitor (omeprazole), a macroglide (clarithromycin) and a beta-lactam (amoxicillin) for 7 to 10 days initially.