Comparative proteomics of Helicobacter species: The discrimination of gastric and enterohepatic Helicobacter species

Helicobacter pylori is a major human pathogen that infects the gastric mucosa and is responsible for a range of infections including gastritis and gastric carcinoma. Although other bacteria within the Helicobacter genus can also infect the gastric mucosa, there are Helicobacter species that infect alternative sites within the gastrointestinal (GI) tract. Two-dimensional gel electrophoresis was used to compare the cellular proteomes of seven non-pylori Helicobacters (H. mustelae, H. felis, H. cinaedi, H. hepaticus, H. fennelliae, H. bilis and H. cholecystus) against the more extensively characterised H. pylori. The different Helicobacter species showed distinctive 2D protein profiles, it was possible to combine them into a single dataset using Progenesis SameSpots software. Principal Component Analysis was used to search for correlations between the bacterial proteomes and their sites of infection. This approach clearly discriminated between gastric (i.e. those which infect in the gastric mucosa) and enterohepatic Helicobacter species (i.e. those bacteria that infect the small intestine and hepatobillary regions of the GI tract). Selected protein spots showing significant differences in abundance between these two groups of bacteria were identified by LC–MS. The data provide an initial insight into defining those features of the bacterial proteome that influence the sites of bacterial infection.