Helicobacter

Abstract The genus Helicobacter is classified in the family Helicobacteriaceae of the class Epsilonproteobacteria , formerly known as the epsilon subclass of the Proteobacteria , with Helicobacter pylori as the type species. There are five other genera in the family: Sulfuricurvum , Sulfurimonas , Sulfurovum , Thiovulum , and Wolinella . Phylogenetic analyses reliant on 16S rRNA gene sequences alone are insufficient for distinguishing closely related helicobacters, which have a high degree of natural transformation and genetic plasticity. Helicobacter species are isolated from the gastrointestinal and hepatobiliary tracts of a variety of mammalian and avian hosts. Laboratory tests requiring the collection of other types of specimen have been developed to assist in the diagnosis of H. pylori infection and may be undertaken under some circumstances. H. pylori is readily isolated by culture from gastric biopsy specimens.