Genetic diversity of canine gastric helicobacters, Helicobacter bizzozeronii and H. salomonis studied by pulsed-field gel electrophoresis

Abstract

Genetic diversity of Helicobacter bizzozeronii and H. salomonis, two recently identified canine gastric Helicobacter spp., was studied by pulsed-field gel electrophoresis (PFGE). All 15 Finnish H. bizzozeronii strains collected between 1991 and 1996 from pet dogs produced different PFGE patterns with all restriction endonucleases studied (AscI, ApaI, SpeI, NotI and PacI) suggesting significant genetic diversity. The five independent H. salomonis strains produced four different patterns with these enzymes; two strains showed identical patterns with all the enzymes. Three separate isolates from one dog had identical patterns, suggesting long-lasting infection with the same strain. H. salomonis strains had several small fragments common for all strains, suggesting relatedness. The PFGE method was shown to be useful for epidemiological studies of canine gastric helicobacter infection. Hybridisation of the DNA digests with digoxigenin-labelled ureB or 16S rRNA gene probes generated by PCR indicated conservation in the localisation of these genes in the H. salomonis genome, because the probes hybridised with similar size fragments of different strains. In contrast, the probes hybridised with different size fragments of H. bizzozeronii strains. Comparison of Southern blots of PFGE patterns digested with SpeI, ApaI and AscI indicated that each species has two 16S rRNA genes and one urease gene. Genome sizes of 11 H. bizzozeronii strains estimated from SpeI and NotI patterns were c. 1.6-1.9 Mb and those of five H. salomonis strains estimated from NotI and PacI patterns were c. 1.7-1.8 Mb.

Emergence of DiverseHelicobacterSpecies in the Pathogenesis of Gastric and Enterohepatic Diseases

“…In this case, DNA-DNA hybridization studies show clearly that H. bizzozeronii and H. salomonis are each genetically homogeneous and distinct from one another, as well as from other canine and feline gastric Helicobacter species. Pulsed-field gel electrophoresis suggests that there is more heterogeneity among strains of H. bizzozeronii than among strains of H. salomonis (196), although this result will require replication with a larger number of strains.…”

Identification and Characterization of a Lipopolysaccharide ,2,3-Sialyltransferase from the Human Pathogen Helicobacter bizzozeronii

“…Among the five non-pylori gastric Helicobacter species reported to be involved in human infections (19), only Helicobacter bizzozeronii has been successfully cultivated from human gastric biopsy specimens (27,30). Humans may acquire the infections as a consequence of direct contact with dogs or cats (35), which are normally colonized by H. bizzozeronii (21). However, although virtually all dogs carry this Helicobacter species, its pathogenic significance in these animals remains unknown (19).…”

Genome Sequence of Helicobacter bizzozeroniiStrain CIII-1, an Isolate from Human Gastric Mucosa

“…Among the five nonpylori gastric Helicobacter species reported to be associated with human infections (5), only Helicobacter bizzozeronii has been successfully cultivated from gastric biopsy tissues of human patients (7,8). Humans potentially acquire the infections as a consequence of direct contact with dogs and cats (10), which are normally colonized by H. bizzozeronii (6). However, although virtually all cats and dogs carry this Helicobacter species, its pathogenic significance in these animals remains unknown (5).…”