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Category:Campylobacter species (view source)
Revision as of 10:04, 14 July 2010
, 10:04, 14 July 2010no edit summary
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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
−===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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