Transmission of Helicobacter pylori between a human and two dogs: A case report

Whereas non-Helicobacter pylori helicobacters, which are frequently detected in the stomachs of dogs and cats as a source of zoonoses, have attracted considerable attention, the role of pets in H. pylori epidemiology is unclear. In our previous study, an H. pylori infection was detected in the stomach of a dog (Dog 1). Here, we investigated the H. pylori infection status in the female offspring of Dog 1 (Dog 2) and its owner within the same household.

Biopsy specimens were obtained from the dog's owner and tested for H. pylori. DNA from gastric biopsy samples of Dog 1, gastric fluid sediment of Dog 2, and bacteria from the stomach of the owner was obtained, and Helicobacter genus- and species-specific PCRs were performed. Then, sequence analyses of the partial region of the ureAB gene were conducted.

Samples from both dogs and the owner reacted positively in the genus-specific PCR and negative in the Helicobacter felis-, Helicobacter bizzozeronii-, and Helicobacter heilmannii sensu stricto-specific PCRs. All three samples also reacted positively in the H. pylori-specific PCR. Sequences of the partial ureAB gene from all subjects were identical.

The results suggested that the two dogs and their owner were infected with an identical H. pylori strain. This report is the first to demonstrate that H. pylori can be transmitted between humans and dogs. Further studies are required to investigate the risk factors for the transmission of H. pylori between humans and dogs from the perspective of preventive epidemiology.