H. Pylori

H. Pylori

Helicobacter pylori (English pronunciation: /ˌhɛlɨkɵˈbæktər pɪˈlɔraɪ/) is a Gram-negative, microaerophilicbacterium that can inhabit various areas of the stomach, particularly the antrum. It causes a chronic low-level inflammation of the stomach lining and is strongly linked to the development of duodenal and gastric ulcers and stomach cancer. Over 80 percent of individuals infected with the bacterium are asymptomatic.

The bacterium was initially named Campylobacter pyloridis, then renamed C. pylori (pylori being the genitiveof pylorus) to correct a Latin grammar error. When 16S ribosomal RNA gene sequencing and other research showed in 1989 that the bacterium did not belong in the genus Campylobacter, it was placed in its own genus, Helicobacter. The genus derived from the ancient Greek hělix/έλιξ "spiral" or "coil". The specific epithet pylōri means "of the pylorus" or pyloric valve (the circular opening leading from the stomach into the duodenum), from the Ancient Greek word πυλωρός, which means gatekeeper.

More than 50% of the world's population harbor H. pylori in their upper gastrointestinal tract. Infection is more prevalent in developing countries, and incidence is decreasing in Western countries. H. pylori's helix shape (from which the generic name is derived) is thought to have evolved to penetrate the mucoid lining of the stomach.