en Internal Medicine & Gastroenterology Internal Medicine & Gastroenterology Original Research Original Research <p> <strong> Background </strong>:The cag pathogenicity island includes a number of genes, including cytotoxin-associated protein A (cagA) and vacuolatingcytotoxin (vacA) genotypes, which are associated with bacterial virulence. Although the role of cagA and vacA in the virulence of Helicobacter pylori (H. pylori) is well-established in epidemiological studies, the relationship between the cagA and vacA genotypes in Iran has yet to be fully elucidated. This study compared the association between cagA and vacA genotypes between peptic ulcer disease (PUD) patients and non-ulcer dyspeptic (NUD) patients. </p><p> <strong> Methods </strong>: This case control study was done on 130 patients with positive H. pylori in histological and Giemsa reports. The case group comprised 65 PUD patients, and the control group included 65 NUD patients. The presence of the cagA and vacA genotypes was determined using polymerase chain reaction (PCR) on biopsy samples, taken via endoscopy. </p><p> <strong> Results </strong>: Both cagA and vacA genotypes were positive in 51.5% (17) of the PUD group and 20% (6) of the NUD group (p=0.009), and both cagA and vacA genotypes were negative in 48.5% (16) and 80% (24) of the case and control groups, respectively (p= 0.03). CagA-positive H. pylori was detected in 41.5% (27) and 24.6% (16) of the case and control groups, respectively (p=0.001), and vacA-positive H. pylori was found in 60% (39) and 46% (30) of the case and control groups, respectively. </p><p> <strong> Conclusion </strong>: Both cagA and vacA genotypes were more prevalent in the PUD patients than in their NUD counterparts among our Iranian samples. It is seems that the determination of these two genotypes in PUD patients is a good screening tool for patient selection for endoscopy and treatment. </p> Dyspepsia, Peptic ulcer, Genes. 671 676 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-1501-2&slc_lang=en&sid=1 Hashem FakhreYaseri hfyaseri@yahoo.com 200319475328460013530 200319475328460013530 Yes Research Center for Gastroenterology and Liver Disease, Department of Internal Medicine and Gastroenterology, Firoozgar Hospital, Iran University of Medical Sciences, Tehran, Iran. Mehdi Shakaraby m_shekaraby@yahoo.com 200319475328460013531 200319475328460013531 No Department and Research Center of Immunology, Iran University of Medical Sciences, Tehran, Iran. Hamid Reza Bradaran baradaran.hr@iums.ac.ir 200319475328460013532 200319475328460013532 No Department of Epidemiology, Iran University of Medical Sciences, Tehran, Iran. Seyed Kamran Soltani Arabshahi soltarab34@gmail.com 200319475328460013533 200319475328460013533 No Department of Internal Medicine, Firoozgar Hospital, Iran University of Medical Sciences, Tehran, Iran. Ali Mohammad Fakhre Yaseri fyasseri@mihanmail.ir 200319475328460013534 200319475328460013534 No School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.