The family helicobacteraceae

Abstract

The family Helicobacteraceae, which lies within the Epsilon subdivision of the Proteobacteria, consists of five genera, Helicobacter, Sulfuricurvum, Sulfurimonas, Sulfurovum, Thiovulum and Wolinella. This family is dominated by the Helicobacter genus which currently consists of 33 validated named species and several Candidatus and unclassified organisms. Its type species, Helicobacter pylori, is recognized as a significant human pathogen responsible for a spectrum of gastrointestinal diseases. Bacteria from the Helicobacter and Wolinella genera are commonly associated with animal and/or human hosts, and in general colonize the oral and/or gastric and intestinal cavities. Interestingly, a number of bacteria recently classified within the Helicobacteraceae family have been isolated from environmental sources including iron- and sulfur-rich freshwater nature reserves, sulfidic caves and springs, hydrothermal vents, and deep-sea sediments. These bacteria belong to the genera Thiovulum, Sulfuricurvum, Sulfurimonas and Sulfurovum. While these bacteria are classified in the Helicobacteraceae family, the significant differences in their niches and lifestyles to Helicobacter species, and their similarities with bacteria belonging to the Nautiliaceae family, may in the future result in their reclassification.