Category:Campylobacter species

Campylobacter species

Campylobacter bacteria are Gram-negative organisms with a characteristic spiral appearance. They live on the mucosa of the intestinal and genital tract and can be commensals or pathogens. Enteric species can cause disease in humans and other species can cause infertility and abortion in cattle and sheep.


Overview

  • Live on mucosa of intestinal and genital tract and can be commensals or pathogens
  • Enteric species cause disease in humans
  • Other species cause infertility and abortion in cattle and sheep
  • Excreted in faeces of birds, (C. jejuni and C. lari) as well as pigs contaminating water and food supplies
  • C. fetus restricted to bovine prepucial mucosa


Characteristics

  • Curved, Gram negative rods
  • Polar flagellum aids motility
  • Daughter cells remain joined giving gull-wing or spiral appearance
  • Microaerophilic
  • Sensitive to drying
  • Thermophilic species - C. jejuni, C. coli
  • Non-thermophilic species e.g. C. fetus
  • Grow on enriched selective media e.g. Skirrow agar in 1-10% carbon dioxide and 5-10% oxygen tension
  • C. jejuni requires increased temperatures for growth
  • Many grow on MacConkey
  • Oxidase positive, non-fermentative
  • C. fetus subspecies venerealis and subspecies fetus have small, round, smooth, translucent colonies
  • C. jejuni has small, flat, grey colonies with watery appearance
  • Smears stained with dilute carbol fuschin for 4 minutes


Pathogenesis and pathogenicity

  • C. fetus subspecies fetus and subspecies venerealis possess a microcapsule (S layer) which resists phagocytosis and serum-mediated destruction and enhances survival in the genital tract
  • Antigens of S layer undergoes antigenic shifts in C. fetus subspecies venerealis, allowing persistence in the host
  • C. jejuni attaches and invades host enterocytes and produces enterotoxin-like substances
  • Flagellae of C. jejuni required for colonisation

Pages in category "Campylobacter species"

The following 5 pages are in this category, out of 5 total.