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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 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


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


Clinical infections

  • Campylobacter fetus subspecies venerealis
    • Venereal infection of cattle
    • Infertility in female cattle
    • Found in glandular crypts of prepuce of bull with no clinical signs - carriers
    • Causes catarrhal inflammation in female genital tract
    • Endometritis prevents implantation until infection gone and causes early embryonic death, occasionally sporadic abortion
    • May remain infertile for 3-5 months before immunity develops, which lasts 4-5 years
    • Effective immunity includes induction of IgA in the vagina and IgG in the uterus
    • Bacteria may persist in the vagina and be transmitted to bulls


Diagnosis

  • Smears stained with dilute carbol fuschin for 4 minutes


Control

Treatment