Difference between revisions of "Campylobacter species"
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| − | + | <big><center>[[Infectious agents and parasites|'''BACK TO INFECTIOUS AGENTS AND PARASITES''']]</center></big> | |
| + | <big><center>[[Bacteria|'''BACK TO BACTERIA''']]</center></big> | ||
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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 | ||
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| + | |||
| + | ===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 | ||
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| + | |||
| + | ===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 | ||
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| + | ===''Campylobacter fetus'' subspecies ''venerealis''=== | ||
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| + | *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 | ||
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| + | ===''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 | ||
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| + | ===[[Intestines - disease due to pathogens#Campylobacter jejuni|''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 [[Intestines Catarrhal Enteritis - Pathology#Undifferentiated Neonatal Calf Diarrhoea|undifferentiated neonatal calf diarrhoea]], a mixed viral enteritis in calves | ||
Revision as of 22:18, 25 August 2008
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
- 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
- Implicated in undifferentiated neonatal calf diarrhoea, a mixed viral enteritis in calves