Genomic characterization of Helicobacter hepaticus: ordered cosmid library and comparative sequence analysis

Abstract

Helicobacter hepaticus is an important pathogen in laboratory mice and induces the development of liver tumors and gastrointestinal disease in susceptible strains of mice. In this study, a miniset of 36 cosmid clones from a genomic library of H. hepaticus was ordered and grouped into four large contigs representing approximately 1 Mb of the H. hepaticus genome using PCR, DNA sequencing, Southern and dot-blot hybridization and pulsed-field gel electrophoresis. From the 200^300 terminal nucleotide sequences of 38 cosmid clones, 56 coding regions were predicted, of which 51 were found to have orthologs in the public databases and five appeared to be unique to H. hepaticus. Of these 51 genes, 36 have orthologs in Helicobacter pylori and 25 display the highest sequence similarity to H. pylori. However, chromosomal positions of these genes are not conserved between these two helicobacters. In addition, 10 H. hepaticus genes had the highest sequence similarity to orthologs in Campylobacter jejuni. The GC content in a randomly selected 21-kb H. hepaticus genomic sequence was 35.8%, which approximates the average between H. pylori (39%) and C. jejuni (30.6%). These results demonstrate that: (1) H. hepaticus is more closely related to H. pylori than C. jejuni ; (2) significant genomic alterations exist between H. hepaticus and H. pylori, including gene organization, protein sequences and GC content, probably in part due to specific adaptation to distinct ecological niches. ß

Potential for proteomic profiling ofHelicobacter pyloriand otherHelicobacterspp. using a ProteinChip®array

“…Two strains of H. pylori have had their genome sequenced and in addition it has been reported recently that the genome of the enterohepatic species, Helicobacter hepaticus , has also had its genome sequenced [3–5]. The immense amount of data now available regarding the genome of H. pylori has translated itself into an increasing number of reports regarding proteomics and H. pylori [6].…”

Hydrogen-Oxidizing Capabilities ofHelicobacter hepaticusand In Vivo Availability of the Substrate

“…After we initiated the present study, a partial genomic sequence analysis of H. hepaticus was reported; 56 coding regions were identified, and one of these is a partial ortholog (85% identity) of hydB of Wolinella succinogenes (9). This would indicate that the bacterium contains the large subunit of a NiFe hydrogenase.…”

Is There Any Association between IgA Nephropathy, Crohn's Disease andHelicobacter pyloriInfection?

“…Enterohepatic and gastric helicobacter species can be found in fecal specimens of children with CD 8 or colonizing the mucosae surface in adults as well. 9 Coccoid Hp was present in the palatine tonsils of patients with Hp stomach infection and with IgAN. Although coccoid Hp, sampled from the oral cavity, has not been cultivated with the current methods, reports conclude that it can be transmitted to the stomach and might be a potential IgAN-pathogenic antigen.…”