Campylobacter Overview

Question 1

Characteristics of Campylobacter

Answer 1

Gram negative spiral, anaerobic or microaerobic. Main infectious strain is C. jejuni

Question 2

Diseases caused by Campylobacter

Answer 2

Campylobacteriosis, gastroenteritis, Guillain-Barre syndrome (correlation due to molecular mimicry)

Question 3

Motility/Adhesion virulence factors - Campylobacter

Answer 3

Outermembrane proteins CadF and FlpA bind to fibronectin in intestinal epithelium. JIPA binds to heat shock protein 90. PEB1 transports aspartate and glutamate which is involved in interaction with epithelial cells. Flagella responsible for motility and adhesion.

Question 4

Toxin virulence factors - campylobacter

Answer 4

Cdt is a toxin composed of 3 subunits, it induces cell cycle arrest at G2 phase and causes apoptosis. cdtA and cdtC bind to host sell surface and cdtB enters the cell. Cholera-like enterotoxins alter fluid resorption capacity which causes diarrhea

Question 5

Invasion virulence factors - campylobacter

Answer 5

Campylobacter invasion antigens – group of proteins which are secreted when contact is made with epithelial cells. Dependent of functional flagellar export apparatus
pVir plasmid encodes type IV secretion system, associated with blood in stools and aids epithelial invasion

Question 6

Pathogenesis of C. jejuni

Answer 6

C. jejuni infection is initially caused from ingestion of contaminated food or water. Infection penetrates GI mucus and adheres to gut enterocytes. Once it has adhered, it induces diarrhoea by toxin release. IgA is responsible for combating this bacterium as it can cross the gut wall.

Question 7

How is C. Jejuni detected?

Answer 7

Faecal samples in microaerobic conditions. Campy blood agar plates and gram stains are also used.

Question 8

How is C. jejuni treated?

Answer 8

Self-limiting. Electrolyte replacement and rehydration used.