Campylobacter species
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BACK TO INFECTIOUS AGENTS AND PARASITES
BACK TO BACTERIA
- Linked to:
- Undifferentiated neonatal calf diarrhoea, a mixed viral enteritis in calves.
- Food poisoning (Campylobacter jejuni).
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
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:
- Fluorescent antibody test on genital discharges from bull/cow
- Vaginal mucus agglutination test
- ELISA to IgA antibodies in vaginal mucus after an abortion
- PCR for detection in semen
- Treatment: dihydrostreptomycin intrauterine for cows and systemically or topically for bulls
- Vaccination: bacterin in oil adjuvant
Campylobacter fetus subspecies fetus
- Sporadic abortion in cows and sheep
- 10% of ovine abortions in the UK
- Enteric organism of sheep, goats and cattle; faecal-oral transmission
- Ingestion during last trimester of pregnancy causes a bacteraemia
- Bacteria reach the uterus
- Necrotic placentitis causes late abortion, still birth or weak lambs
- Sporadic abortion in cattle
- Aborted lambs may have round necrotic lesions on surface of liver
- Aborting ewes source of infection for vulnerable animals
- Up to 20% of flock may abort
- Solid immunity developed
- S layer immunodominant antigen
- Diagnosis: hepatic lesions in lambs; presence of organisms in foetal abomasum; isolation and identification
- Treatment/control: isolate aborting ewes; destroy placenta; move other ewes to clean pasture; vaccinate flock with bacterin during outbreak and prophylactically; chlortetracycline in feed in an outbreak
Diagnosis
- Smears stained with dilute carbol fuschin for 4 minutes