Background: Helicobacter pylori (H. pylori) has various strains associated with human infections. H. pylori, H. heilmannii, and H. felis are the most common strains in humans. H. pylori is associated with several human diseases such as chronic gastritis, peptic ulcer, mucous membrane lymphoma, and gastric adenocarcinoma. This study aimed to determine the prevalence rates of H. felis and H. heilmannii and the effect of co-infection with H. pylori in gastric biopsy specimens of patients. Methods: Totally, 80 gastric biopsy specimens were taken by a physician from the patients referred to Shahid Beheshti Hospital, Hamadan City, Iran. PCR test was used to confirm the presence of H. pylori in samples that had positive rapid urease tests. Moreover, the ureB gene and ureA and ureB genes were used for H. heilmannii and H. felis, respectively. Results: Of the study patients, 61.5% were females, and 38.5% were males with a mean age of 37.8 years. Of 80 biopsies, 50% were H. pylori-positive, 53.8% were H. heilmannii-positive, but no H. felis was identified in any sample. Results indicate that smoking, having a history of gastrointestinal diseases, and taking certain medications can be risk factors for H. pylori. Conclusion: Any agent contributing to gastric mucosal damage can enhance the susceptibility to bacterial contamination. Overall, the results indicate a low probability of interactions between H. pylori, H. heilmannii, and H. felis.

Background: Helicobacter pylori (H. pylori) has various strains associated with human infections. H. pylori, H. heilmannii, and H. felis are the most common strains in humans. H. pylori is associated with several human diseases such as chronic gastritis, peptic ulcer, mucous membrane lymphoma, and gastric adenocarcinoma. This study aimed to determine the prevalence rates of H. felis and H. heilmannii and the effect of co-infection with H. pylori in gastric biopsy specimens of patients. Methods: Totally, 80 gastric biopsy specimens were taken by a physician from the patients referred to Shahid Beheshti Hospital, Hamadan City, Iran. PCR test was used to confirm the presence of H. pylori in samples that had positive rapid urease tests. Moreover, the ureB gene and ureA and ureB genes were used for H. heilmannii and H. felis, respectively. Results: Of the study patients, 61.5% were females, and 38.5% were males with a mean age of 37.8 years. Of 80 biopsies, 50% were H. pylori-positive, 53.8% were H. heilmannii-positive, but no H. felis was identified in any sample. Results indicate that smoking, having a history of gastrointestinal diseases, and taking certain medications can be risk factors for H. pylori. Conclusion: Any agent contributing to gastric mucosal damage can enhance the susceptibility to bacterial contamination. Overall, the results indicate a low probability of interactions between H. pylori, H. heilmannii, and H. felis.