Campylobacter: Difference between revisions
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| image_captiogggn = Campylobacter bacteria |
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| regnum = [[Bacterium|Bacteria]] |
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| phylum = [[Proteobacteria]] |
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Revision as of 15:37, 28 April 2009
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| Genus: | Campylobacter Sebald and Véron 1963
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C. coli | |
The genus Campylobacter, (meaning 'twisted bacteria') first discovered in 1963[1], describes Gram-negative, spiral, microaerophilic bacteria. Motile, with either uni- or bi-polar flagella, the organisms have a characteristic spiral/corkscrew appearance (see photo) and are oxidase-positive.[2] Campylobacter jejuni is now recognized as one of the main causes of bacterial foodborne disease in many developed countries.[3] At least a dozen species of Campylobacter have been implicated in human disease, with C. jejuni and C. coli the most common.[2] C. fetus is a cause of spontaneous abortions in cattle and sheep, as well as it is an opportunisitic pathogen in humans.[4]
Genome
The genomes of several Campylobacter species have been sequenced, providing insights into their mechanisms of pathogenesis.[5] The first Campylobacter genome to be sequenced was C. jejuni, in 2000.[6]
Campylobacter species contain two flagellin genes in tandem for motility, flaA and flaB. These genes undergo intergenic recombination, further contributing to their virulence. [7] Non-motile mutants do not colonize.
Pathogenesis
Campylobacteriosis is an infection by campylobacter.[8] The common routes of transmission are fecal-oral, person-to-person sexual contact, ingestion of contaminated food or water, and the eating of raw meat. It produces an inflammatory, sometimes bloody, diarrhea, periodontitis[9] or dysentery syndrome, mostly including cramps, fever and pain. The infection is usually self-limiting and in most cases, symptomatic treatment by reposition of liquid and electrolyte replacement is enough in human infections. The use of antibiotics, on the other hand, is controversial.
Cause
The exact cause of campylobacteriosis has not been clarified yet, but seem to involve multiple mechanisms. One mechanism is invasion into epithelial cells of the gut, which is generally low, but damages these cells. The sites of tissue injury include the jejunum, the ileum, and the colon.
Most strains of C jejuni produce a toxin (cytodistending toxin) that hinders the cells to divide and activate the immune system. This helps the bacteria to evade immune system and survive for a limited time in the cells. For a while, it was thought that also a cholera-like enterotoxin was made, but this appeared not to be the case. The organism produces diffuse, bloody, edematous, and exudative enteritis. In a small number of cases, the infection may be associated with hemolytic uremic syndrome and thrombotic thrombocytopenic purpura through a poorly understood mechanism.
References
- ^ Nachmankin I; Szymanski CM; Blaser J (editors) (2008). Campylobacter (3rd ed.). ASM Press. pp. 3–25. ISBN 9781555814373.
{{cite book}}:|author=has generic name (help)CS1 maint: multiple names: authors list (link) - ^ a b Ryan KJ; Ray CG (editors) (2004). Sherris Medical Microbiology (4th ed.). McGraw Hill. pp. 378–80. ISBN 0838585299.
{{cite book}}:|author=has generic name (help)CS1 maint: multiple names: authors list (link) - ^ Moore JE; et al. (2005). "Campylobacter". Vet Res. 36 (3): 351–82. doi:10.1051/vetres:2005012. PMID 15845230.
{{cite journal}}: Explicit use of et al. in:|author=(help) - ^ Sauerwein R, Bisseling J, Horrevorts A (1993). "Septic abortion associated with Campylobacter fetus subspecies fetus infection: case report and review of the literature". Infection. 21 (5): 331–3. doi:10.1007/BF01712458. PMID 8300253.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Fouts DE; et al. (2005). "Major structural differences and novel potential virulence mechanisms from the genomes of multiple Campylobacter species". PLoS Biol. 3 (1): e15. doi:10.1371/journal.pbio.0030015. PMID 15660156.
{{cite journal}}: Explicit use of et al. in:|author=(help)CS1 maint: unflagged free DOI (link) - ^ Parkhill; et al. (2000). "The genome sequence of the food-borne pathogen Campylobacter jejuni reveals hypervariable sequences". Nature. 403: 665–668. doi:10.1038/35001088. PMID 10688204.
{{cite journal}}: Explicit use of et al. in:|author=(help) - ^ Grant C, Konkel M, Cieplak W, Tompkins L (1993). "Role of flagella in adherence, internalization, and translocation of Campylobacter jejuni in nonpolarized and polarized epithelial cell cultures". Infect Immun. 61 (5): 1764–71. PMID 8478066.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ cdc.gov
- ^ Humphrey, Tom; et al. (2007). "Campylobacters as zoonotic pathogens: A food production perspective <internet>". International Journal of Food Microbiology. 117 (3): 237. doi:10.1016/j.ijfoodmicro.2007.01.006.
{{cite journal}}: Cite has empty unknown parameter:|coauthors=(help); Explicit use of et al. in:|first=(help)