Prevalence, diversity and public health implications of Helicobacter species in pet and stray dogs

Abstract

BackgroundIt is probable that humans can acquire H. pylori and nonH. pylori Helicobacter infections via domestic animals. The prevalence and risk factors of infections of Helicobacter species in canines of Taipei city were therefore analysed in this study. Materials and methodsA total of 95 canine faecal samples were collected from different animal shelters and hospitals in Taipei city. Total DNA was extracted for semi-nested PCR detection of Helicobacter species. The PCR products were sequenced for further comparative database and phylogenetic analyses. ResultsThe overall prevalence of Helicobacter species in canines of Taipei city was 75.79% (72/95). Two gastric, seven enterohepatic and two unclassified Helicobacter species were identified, all of which have been implicated in the aetiology of human diseases. The predominant species detected included H. canis (27.78%), H. pylori (26.39%), H. canicola (18.06%), and H. bilis (13.89%) in decreasing order, while H. canadensis and H. typhlonius were identified for the first time in canines. The genotypes in H. pylori and H. canicola clusters grouped together, with their respective reference strains, showed a close evolutionary distance in the phylogenetic tree, indicating a common ancestry may have existed in these clusters respectively. The residential region of canines, dog living status (pet or stray) and breed (purebred or mixed-breed) are the risk factors associated with Helicobacter infections in the canines examined. ConclusionThe high prevalence of Helicobacter infections in canines highlights a potential public health risk of zoonotic transmission among dogs, humans and other animals, and therefore, the need for proper methods in controlling the transmission routes. In addition, the 16S rRNA gene amplification method was found to be useful for bacterial identification and phylogenetic analysis.