en Public Health Public Health پژوهشي Original Article <div style="text-align: justify;"><span style="font-size:14px;"><span style="font-family:times new roman;"><strong>Background:</strong> <em>Helicobacter pylori </em>play a significant etiological role in various digestive diseases. Peptic ulcer is caused by <em>H. pylori</em>, which destroys the duodenum mucus and is often observed in the individuals consuming tobacco, spicy and heavy meals, alcohol, coffee, and tranquilizers. Several studies have indicated that duodenal ulcer promoting genes <em>dupA</em> and <em>cagA</em> are involved in <em>H. pylori </em>etiology. The present study aimed to evaluate the correlation between these genes and peptic ulcer.&nbsp;<br> <strong>Methods: </strong>In this study, 500 stomach biopsy samples were assessed based on the rapid urease test and polymerase chain reaction (PCR) for <em>H. pylori</em> infection, followed by histological and microscopic examinations.<br> <strong>Results:</strong> The <em>dupA</em> and <em>cagA</em> genes were subjected to PCR. Although <em>dupA</em> showed no significant correlation with peptic ulcer, the <em>cagA</em> genotype had a significant association with peptic ulcer (<em>P</em> < 0.05). Similar to the <em>dupA</em> gene, blood group was not observed to be correlated with <em>H. pylori</em> infection.<br> <strong>Conclusion:</strong> According to the results, there are significant correlations between tobacco use (<em>P</em> < 0.05), tranquilizer use (<em>P</em> < 0.05), and meteorism (<em>P</em> < 0.05) with peptic ulcer. In addition, the expression of the <em>cagA</em> and <em>dupA</em> genes was investigated in patients with non-ulcer dyspepsia and peptic ulcer.</span></span></div> Helicobacter pylori, Peptic ulcer, Real time technique, dupA, cag-A 159 163 http://jhehp.zums.ac.ir/browse.php?a_code=A-10-178-3&slc_lang=en&sid=1 Hamid Reza Zaraatgar Gohardani hzara_2016@yahoo.com 10031947532846009641 10031947532846009641 No Department of Basic Sciences, School of Microbiology Islamic Azad University, Damghan, Iran. Ehsan Moghanloo moghanloo.ehsan@gmail.com 10031947532846009642 10031947532846009642 No Department of Microbiology and Immunology, School of Medicine, Kashan University of Medical Sciences, Kashan, Iran. Parisa Badameh parsa2020@gmail.com 10031947532846009643 10031947532846009643 No Department of Microbiology, College of Basic Science and Biology,Islamic Azad University Varamin, Iran. Soheila Rezaei rezaeis@yahoo.com 10031947532846009644 10031947532846009644 No Department of Molecular Genetics, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran. Vahid Babaei v.babaei546@yahoo.com 10031947532846009645 10031947532846009645 No Department of Medical Genetics, Iran University of Medical Sciences,Tehran, Iran. Shahram Teimourian teimourian.sh@iums.ac.ir 10031947532846009646 10031947532846009646 Yes Department of Virology, Pasture Institute of Iran,Tehran, Iran.