Background and purpose: Helicobacter pylori is one of the most prevalent agents causing gastric infection.  Most of the type I strains genome containing cag pathogenicity island (i.e. cagA) result in peptic ulcer and gastric cancer. Antibiotics are amongst the main treatments but drug resistance may cause treatment failure. The aim of current research was to investigate the presence of cagA in H. pylori samples and their antibiotic resistance patterns.
Materials and methods: A descriptive study was performed in 86 patients. The endoscopy specimen was used fosr rapid urease test and culture and preparation of paraffin blocks to observe lam of tissue and performing PCR method. Samples were grown in standard media and grown colonies in culture medium were identified using catalase and oxidase tests. Antibiotic susceptibility tests were performed by antibiogram.
Results: In this study, the rapid urease test, tissue lam observation, culture results and PCR analysis were positive in 45.3%, 53.4%, and 55.9%, and 80.2%, respectively. CagA gene was detected in 69.56% of the samples. Among patients with positive culture, highest rates of resistance were found to metronidazole, amoxicillin, ciprofloxacin, clarithromycin, and furazolidone, while the lowest rate of resistance was to tetracycline.
Conclusion: Compared with other methods, PCR analysis was found to be more appropriate. Current study showed that H. pylori strains in Iran are increasingly resistant to clarithromycin, and furazolidone, and metronidazole.