Helicobacter
From Wikipedia, the free encyclopedia
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 Scanning electron micrograph of Helicobacter bacteria.
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H. acinonychis |
Helicobacter is a genus of Gram-negative bacteria possessing a characteristic spiral shape. They were initially considered to be members of the Campylobacter genus, but since 1989 they have been grouped in their own genus[1],[2].
Some species have been found living in the lining of the upper gastrointestinal tract, as well as the liver of mammals and some birds[3]. The most widely known species of the genus is H. pylori which is a human pathogen and is responsible for most cases of peptic ulcer, chronic gastritis, duodenitis, and stomach cancer. It also serves as the type species of the genus.
Helicobacter spp. are able to thrive in the strongly acidic mammalian stomach by producing large quantities of an enzyme called urease, which locally raises the pH from ~2 to a more biocompatible range (pH 6-7)[4]. Bacteria belonging to this genus are usually susceptible to antibiotics such as penicillin, are microaerophilic (require small amounts of oxygen), and are fast-moving with multiple flagella[5].
[edit] References
- ^ Goodwin CS; Armstrong JA; Chilvers T; Peters M; Collins MD; Sly L; McConnell W; Harper WES. (1989). "Transfer of Campylobacter pylori and Campylobacter mustelae to Helicobacter gen. nov. as Helicobacter pylori comb. nov. and Helicobacter mustelae comb. nov., respectively.". Int. J. Syst. Bacteriol. 39: 397–405.
- ^ Vandamme P; Falsen E; Rossaq R; Hoste B; Seagers P; Tytgat R; De Lay J. (1991). "Revision of Campylobacter, Helicobacter, and Wolinella taxonomy: emendation of generic descriptions and proposal of Arcobacter gen. nov.". Int. J. Syst. Bacteriol. 41: 88–103.
- ^ Ryan KJ; Ray CG (editors) (2004). Sherris Medical Microbiology, 4th ed., McGraw Hill. ISBN 0-8385-8529-9.
- ^ Dunn BE; Cohen H; Blaser MJ. (1997). "Helicobacter pylori.". Clin Microbiol Rev. 10: 720–741.
- ^ Hua JS; Zheng PY; Ho B (1999). "Species differentiation and identification in the genus of Helicobacter.". World Journal of Gastroenterology. 5 (1): 7–9.
