Difference between revisions of "Campylobacter species"
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* Linked to: | * Linked to: | ||
** [[Intestines - Catarrhal Enteritis#Undifferentiated Neonatal Calf Diarrhoea|Undifferentiated neonatal calf diarrhoea]], a mixed viral enteritis in calves. | ** [[Intestines - Catarrhal Enteritis#Undifferentiated Neonatal Calf Diarrhoea|Undifferentiated neonatal calf diarrhoea]], a mixed viral enteritis in calves. | ||
| − | + | ||
===Overview=== | ===Overview=== | ||
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*Thermophilic species - ''C. jejuni, C. coli'' | *Thermophilic species - ''C. jejuni, C. coli'' | ||
*Non-thermophilic species e.g. ''C. fetus'' | *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 | + | *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 | *''C. jejuni'' requires increased temperatures for growth | ||
*Many grow on MacConkey | *Many grow on MacConkey | ||
| Line 38: | Line 38: | ||
*Antigens of S layer undergoes antigenic shifts in ''C. fetus'' subspecies ''venerealis'', allowing persistence in the host | *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 | *''C. jejuni'' attaches and invades host enterocytes and produces enterotoxin-like substances | ||
| + | *Flagellae of ''C. jejuni'' required for colonisation | ||
| Line 77: | Line 78: | ||
| − | ===''Campylobacter jejuni''=== | + | ===[[Intestines - disease due to pathogens#Campylobacter jejuni|''Campylobacter jejuni'']]=== |
*Widespread on farms - hyperendemic | *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 | *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 | *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 | |
| − | *Most chicken carcasses contaminated, leading to food poisoning in people | + | *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 | ||
Revision as of 08:49, 18 May 2008
- Linked to:
- Undifferentiated neonatal calf diarrhoea, a mixed viral enteritis in calves.
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
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
- 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
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
Diagnosis
- Smears stained with dilute carbol fuschin for 4 minutes