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| − | ===Overview===
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| − | *Live on mucosa of intestinal and genital tract and can be commensals or pathogens
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| − | *Enteric species cause disease in humans
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| − | *Other species cause infertility and abortion in cattle and sheep
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| − | *Excreted in faeces of birds, (''C. jejuni'' and ''C. lari'') as well as pigs contaminating water and food supplies
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| − | *''C. fetus'' restricted to bovine prepucial mucosa
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| − | ===Characteristics===
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| − | *Curved, Gram negative rods
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| − | *Polar flagellum aids motility
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| − | *Daughter cells remain joined giving gull-wing or spiral appearance
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| − | *Microaerophilic
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| − | *Sensitive to drying
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| − | *Thermophilic species - ''C. jejuni, C. coli''
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| − | *Non-thermophilic species e.g. ''C. fetus''
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| − | *Grow on enriched selective media e.g. Skirrow agar in 1-10% carbon dioxide and 5-10% oxygen tension
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| − | *''C. jejuni'' requires increased temperatures for growth
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| − | *Many grow on MacConkey
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| − | *Oxidase positive, non-fermentative
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| − | *''C. fetus'' subspecies ''venerealis'' and subspecies ''fetus'' have small, round, smooth, translucent colonies
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| − | *''C. jejuni'' has small, flat, grey colonies with watery appearance
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| − | *Smears stained with dilute carbol fuschin for 4 minutes
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| − | ===Pathogenesis and pathogenicity===
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| − | *''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
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| − | *Antigens of S layer undergoes antigenic shifts in ''C. fetus'' subspecies ''venerealis'', allowing persistence in the host
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| − | *''C. jejuni'' attaches and invades host enterocytes and produces enterotoxin-like substances
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| − | *Flagellae of ''C. jejuni'' required for colonisation
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