Brief Article
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World J Gastroenterol. Sep 14, 2013; 19(34): 5685-5692
Published online Sep 14, 2013. doi: 10.3748/wjg.v19.i34.5685
Diversity of Helicobacter pylori genotypes in Iranian patients with different gastroduodenal disorders
Farzam Vaziri, Shahin Najar Peerayeh, Masoud Alebouyeh, Tabassom Mirzaei, Yoshio Yamaoka, Mahsa Molaei, Nader Maghsoudi, Mohammad Reza Zali
Farzam Vaziri, Shahin Najar Peerayeh, Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran 14115-331, Iran
Masoud Alebouyeh, Tabassom Mirzaei, Mohammad Reza Zali, Gastroenterology and Liver Diseases Research Center, Shahid Beheshti University of Medical Sciences, Tehran 19835-187, Iran
Yoshio Yamaoka, Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Oita 879-5593, Japan
Yoshio Yamaoka, Department of Medicine-Gastroenterology, Baylor College of Medicine, Houston, TX 77030, United States
Mahsa Molaei, Basic and Molecular Epidemiology of Gastrointestinal Disorders Research Center, Shahid Beheshti University of Medical Sciences, Tehran 19835-187, Iran
Nader Maghsoudi, Neuroscience Research Center (NRC), Shahid Beheshti University of Medical Sciences, Tehran 19615-1178, Iran
Author contributions: Najar Peerayeh S, Alebouyeh M and Yamaoka Y contributed equally to this work; Vaziri F performed the research and wrote the paper; Alebouyeh M and Vaziri F designed the research and analyzed the data; Mirzaei T collected the biopsy samples and cultured the bacteria; Molaei M helped this project as a pathologist; Alebouyeh M, Najar Peerayeh S, Maghsoudi N, Yamaoka Y and Zali MR supervised the research; Yamaoka Y edited the manuscript.
Supported by Gastroenterology and Liver Diseases Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Iran National Science Foundation, INSF; and a PhD grant from the Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran; Grants-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan, No. 22390085, 22659087, 24406015 and 24659200; Special Coordination Funds for Promoting Science and Technology from the MEXT of Japan, and a Research Fund at the Discretion of the President, Oita University
Correspondence to: Shahin Najar Peerayeh, PhD, Associate Professor, Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran 14115-331, Iran. najarp_s@modares.ac.ir
Telephone: +98-21-82883870 Fax: +98-21-82884555
Received: August 19, 2012
Revised: September 11, 2012
Accepted: November 14, 2012
Published online: September 14, 2013
Abstract

AIM: To investigate the diversity of Helicobacter pylori (H. pylori) genotypes and correlations with disease outcomes in an Iranian population with different gastroduodenal disorders.

METHODS: Isolates of H. pylori from patients with different gastroduodenal disorders were analyzed after culture and identification by phenotypic and genotypic methods. Genomic DNA was extracted with the QIAamp DNA mini kit (Qiagen, Germany). After DNA extraction, genotyping was done for cagA, vacA (s and m regions), iceA (iceA1, iceA2) and babA with specific primers for each allele using polymerase chain reaction (PCR). All patients’ pathologic and clinical data and their relation with known genotypes were analyzed by using SPSS version 19.0 software. χ2 test and Fisher’s exact test were used to assess relationships between categorical variables. The level of statistical significance was set at P < 0.05.

RESULTS: A total of 71 isolates from 177 patients with different gastroduodenal disorders were obtained. Based on analysis of the cagA gene (positive or negative), vacA s-region (s1 or s2), vacA m-region (m1 or m2), iceA allelic type (iceA1 and iceA2) and babA gene (positive or negative), twenty different genotypic combinations were recognized. The prevalence of cagA, vacA s1, vacA s2, vacA m1, vacA m2, iceA1, iceA2, iceA1+iceA2 and babA were 62%, 78.9%, 19.7%, 21.1%, 78.9%, 15.5%, 22.5%, 40.8% and 95.8%, respectively. Interestingly, evaluation of PCR results for cagA in 6 patients showed simultaneous existence of cagA variants according to their size diversities that proposed mixed infection in these patients. The most prevalent genotype in cagA-positive isolates was cagA+/vacAs1m2/iceA1+A2/babA+ and in cagA-negative isolates was cagA-/vacAs1m2/iceA-/babA+. There were no relationships between the studied genes and histopathological findings (H. pylori density, neutrophil activity, lymphoid aggregation in lamina propria and glandular atrophy). The strains which carry cagA, vacAs1/m1, iceA2 and babA genes showed significant associations with severe active chronic gastritis (P = 0.011, 0.025, 0.020 and 0.031, respectively). The vacAs1 genotype had significant correlation with the presence of the cagA gene (P = 0.013). Also, babA genotype showed associations with cagA (P = 0.024). In the combined genotypes, only cagA+/vacAs1m1/iceA2/babA+ genotype showed correlation with severe active chronic gastritis (P = 0.025).

CONCLUSION: This genotyping panel can be a useful tool for detection of virulent H. pylori isolates and can provide valuable guidance for prediction of the clinical outcomes.

Keywords: Helicobacter pylori, cagA, vacA, iceA, babA