幽门螺杆菌
幽门螺杆菌
科学分类
域： 细菌域 Bacteria 门： 变形菌门 Proteobacteria 纲： ε-变形菌纲 Epsilonproteobacteria 目： 弯曲菌目 Campylobacterales 科： 弯曲菌科 Campylobacteraceae 属： 螺杆菌属 Helicobacter 种： 幽门螺杆菌 H. pylori
二名法
Helicobacter pylori (Marshall et al. 1985) Goodwin et al. ****
模式株
Royal Perth Hospital 13487 = ATCC 43504 = CCUG 15815 B = CCUG 17874 = CCUG 39500 = CIP 103995 = DSM 4867 = JCM 12093 = LMG 18041 = LMG 19449 = NCTC 11637

幽门螺杆菌或幽门螺旋杆菌、幽门螺旋菌（学名：Helicobacter pylori，发音为/ˌhɛlɪkɵˈbæktər pɪˈlɔəraɪ/）是革兰氏阴性、微需氧的细菌，生存于胃部及十二指肠的各区域内。它会引起胃黏膜轻微的慢性发炎，甚或导致胃及十二指肠溃疡与胃癌。超过80%的带原者并不会表露病征。

幽门螺杆菌最初被命名为幽门弯曲菌（Campylobacter pyloridis），后为修正拉丁语语法错误而变为C. pylori。****年，16S rRNA基因定序等研究显示其并不属于弯曲菌属，幽门螺杆菌便被独立归类至螺杆菌属。螺杆菌属（Helicobacter）源自古希腊的词汇「hělix/έλιξ」（意为螺旋或缠绕）。属名加词「pylōri」则是指「幽门的」或幽门阀（从胃部通往十二指肠的圆状开口），源自古希腊词汇「πυλωρός」，意为守门人。 一旦家庭中成年人被发现有「胃幽门螺旋杆菌」的感染时，共同生活的孩童亦会有相同的感染现象。

Helicobacter pylori, previously Campylobacter pylori, is a gram-negative, microaerophilic bacterium found usually in the stomach. It was identified in 1982 by Australian scientists Barry Marshall and Robin Warren, who found that it was present in a person with chronic gastritis and gastric ulcers, conditions not previously believed to have a microbial cause. It is also linked to the development of duodenal ulcers and stomach cancer. However, over 80% of individuals infected with the bacterium are asymptomatic, and it may play an important role in the natural stomach ecology.