Drug resistance of urease-positive bacteria other than Helicobacter pylori and distribution of urease genes in patients with gastritis

Urease-positive bacteria other than Helicobacter pylori have been shown to be present in the mouth, stomach, intestines, urinary tract, and skin. The aim of this study was to evaluate the prevalence of non-H. pylori urease-positive bacteria in the gastric biopsies of patients with gastritis and the antibiotic resistance pattern of the isolates, along with the prevalence of ureA, ureB, and ureC genes. In this study, 165 biopsies were collected from the gastric antrum of patients with gastritis referred to hospitals by a gastroenterologist. After Rapid Urease Test, the samples were transferred to the microbiology laboratory using a Brain Heart Infusion broth transfer medium. Next, the non-H. pylori bacteria were identified by the standard microbiological methods. Also, the H. pylori-positive samples were detected using the pathological testing, stool antigen detection test, and enzyme linked sorbent assay. However, after the growth and purification of microorganisms, the urease test was carried out again. In the next step, the DNAs of all confirmed isolates were extracted and the presence of ureA, ureB, and ureC genes was evaluated using the specific primers by the PCR method. Among the 100 urease-positive biopsies, 77 samples were infected with H. pylori and 23 were non-H. pylori-positive. Staphylococcus epidermidis was the most prevalent non-H. pylori-positive bacteria in this study. The antibiotic resistance pattern of the bacteria showed that tetracycline and erythromycin were the least effective antibiotics against the gram-positive and -negative, respectively. However, the lowest resistance rate of gram-positive bacteria was detected against co-trimoxazole, while cefotaxime, chloramphenicol, and ceftriaxone were the most effective antibiotics against the gram-negative bacteria. In addition, the ureA gene was detected among 21.73 % of the non-H. pylori isolates, while 8.69 % and 43.47 % of them were ureB and ureC positive, respectively. This study showed a considerable significance of non-H. pylori urease-positive bacteria causing gastritis. It seems that the diagnosis of these organisms can be effective in treatment of patients with gastritis. Also, the ureC gene was predominant to produce the urease in these isolates. •Seventy-seven percent of the biopsy samples were infected with H. pylori and 23% were non-H. pylori-positive.•Staphylococcus epidermidis was the most prevalent non-H. pylori-positive bacteria.•Tetracycline and erythromycin were the leas