Identification and Prevalence of Helicobacter Pylori Virulence Genes Baba and Caga in Wolinella Isolates from the Oral Cavity of Dogs

Wolinella spp. and Helicobacter spp. have been repeatedly reported in the oral cavity of dogs and are associated with periodontal disease. Wolinella strains predominate in the oral cavity of dogs. The only known species of this genus, Wolinella succinogenes, was considered non-pathogenic until sequence analysis of its genome revealed homologous genes resembling virulence factors in Helicobacter pylori. This has led researchers to question the nonpathogenic status of W. succinogenes. The cagA and babA genes are examples of crucial virulence factors in H. pylori pathogenesis; thus, the present study evaluated the prevalence of these genera and assessed the Wolinella strain genome in terms of the presence of these virulence factors. Multiple specific PCR tests were performed on oral secretion samples collected from 62 dogs by sterile cytobrush to evaluate the genera, species, and presence of virulence genes. The species-specific 16s rRNA genes from the Helicobacter and Wolinella genera were detected in 58.06% and 83.87% of the oral samples, respectively. H. pylori were not detected in the specimens. No cagA and babA genes were detected in the Wolinella spp. or non-pylori Helicobacter genomes. Our results confirmed that Wolinella spp. is the predominant population compared to Helicobacter in the oral cavity of dogs. Apparently, the incidence of Helicobacter infections is generally associated with non-pylori Helicobacter organisms. Despite the hypothesis of genomic homology between W. succinogenes and H. pylori, cagA and babA virulence genes were not identified in any of the oral samples from the dogs.