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
Campylobacter fetus subspecies venerealis
Campylobacter fetus subspecies fetus
Campylobacter jejuni
- Widespread on farms - hyperendemic
- Carried as commensals in intestines of cattle, sheep, dogs, wild birds and especially chickens
- Farm animals regularly exposed via faecal-oral route; maternal antibody protects while active immunity develops
- Animals with little exposure are very susceptible, e.g. humans, pets
- Most chicken carcasses contaminated, leading to food poisoning and enterocolitis in people from uncooked meat
- Colonisation, attachment and invasion of colonic enterocytes; toxin production
- Necrosis of colonic absorptive epithelial cells, erosion of mucosa, crypt abscesses, inflammatory infiltrate of neutrophils into mucosa causes colitis
- Enteritis and diarrhoea in susceptible dogs; treatment with enrofloxacin
- Causes abortion in ewes
- Usually asymptomatic infections in chickens and turkeys, but occasional outbreaks of avian hepatitis occur with decreased egg production, loss of condition, haemorrhage and necrosis of liver; phase contrast microscopy demonstrates curved rods in bile; in-feed dihydrostreptomycin sulphate in outbreak
- Implicated in undifferentiated neonatal calf diarrhoea, a mixed viral enteritis in calves
Pages in category "Campylobacter species"
The following 5 pages are in this category, out of 5 total.