Helicobacter

**Semantic type:** Bacterium

**Definition:** A genus of gram-negative helical, curved, or straight microaerophilic bacteria with rounded ends and multiple sheathed flagella (unipolar or bipolar and lateral) with terminal bulbs. Form nonpigmented, translucent colonies, 1-2 mm in diameter. Catalase and oxidase positive. Found in gastric mucosa of primates, including human beings and ferrets. Some species are associated with gastric and peptic ulcers and gastric cancer. The type species is Helicobacter pylori.

**Synonyms:** - HELICOBACTER