en Gastroenterology Gastroenterology Original Research: Clinical Science Original Research: Clinical Science <strong>Background: </strong>Crohn&#39;s disease and Ulcerative colitis are known as inflammatory bowel disease with high morbidity which are as a result of increasing immune responses to intestinal microbiota in genetically susceptible individuals. The association of adherent invasive Escherichia coli with Crohn&#39;s disease in human has been discussed for decades. The principal aim of this study was to assess the relationship between adherent invasive Escherichia coli in Iranian patients with Crohn&#39;s disease.<br> <strong>&nbsp;&nbsp; Methods: </strong>The presence of adherent invasive Escherichia coli DNA and viable adherent invasive Escherichia coli cells were identified through PCR and conventional culture methods, respectively. All the specimens were subsequently cultured in Hi Chrome Agar medium.<br> <strong>&nbsp;&nbsp; Results:</strong> Using molecular assay, the invasive plasmid antigen H and invasion-association locus genes were detected from tissue samples confirming the presence of adherent-invasive Escherichia coli. The invasive plasmid antigen H was detected in 46.7% of CD and 13.3% of healthy peoples. The invasion-association locus gene was found in 36.7% of patients with Crohn&#39;s disease and 10% in individuals without IBD.<br> <strong>&nbsp;&nbsp; Conclusion:</strong> This study demonstrated an increased frequency of adherent invasive E. coli with invasive plasmid antigen H and invasion-association locus genes from patients with CD in comparison to control individuals. Moreover, it was shown that adherent invasive E. coli with the invasive plasmid antigen H and invasion-association locus genes can act as a predisposing factor in the development of IBD.<br> &nbsp; Crohn Disease, Inflammatory bowel disease, Escherichia coli, PCR 57 61 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-3650-1&slc_lang=en&sid=1 Akram Sarabi Asiabar Sarabi_e25@yahoo.com 200319475328460036659 200319475328460036659 No Department of Microbiology, Karaj Branch, Islamic Azad University, Karaj, Iran. Hamid Asadzade Aghdaei Hamid.asadzadeh@gmail.com 200319475328460036660 200319475328460036660 No Basic and Molecular Epidemiology of Gastroenterology Disorders Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Azar Sabokbar sabokbarr@kiau.ac.ir 200319475328460036661 200319475328460036661 No Department of Microbiology, Karaj Branch, Islamic Azad University, Karaj, Iran. Mohammd Reza Zali nnzali@hotmail.com 200319475328460036662 200319475328460036662 No Department of Inflammatory Bowel Disease, Research Center for Gastroenterology and Liver Disease, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Mohammad Mehdi Feizabadi mfeizabadi@tums.ac.ir 200319475328460036663 200319475328460036663 Yes Department of Microbiology, School of Medicine, Tehran University of Medical Science, Tehran, Iran, & Thoracic Research Center, Imam Khomeini Hospital, Tehran, Iran.