Somayyeh Gharibi - Foodborne and Waterborne Disease Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran. The Persian Gulf Marine Biotechnology Research Center, The Persian Gulf Biomedical
Masoud Alebouyeh - Pediatric Infections Research Center, Research Institute for Children’s Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Tahereh Falsafi - Department of Microbiology, Faculty of Biological Science, Alzahra University, Tehran, Iran.
Marzyeh Gharibi - Department of Microbiology, Food and Drug Deputy, Bushehr University of Medical Sciences, Bushehr, Iran.
Mitra Rezaei - Virology Research Center, National Research Institutes of Tuberculosis and Lung diseases (NRITLD), Shahid Beheshti University of Medical Sciences ,Tehran, Iran
Mohamad Reza Zali - Gastroenterology and Liver Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran.

BACKGROUND AND OBJECTIVESHelicobacter pylori (H. pylori) is a bacterial class-I carcinogen that specifically colonizes the gastric epithelium of humans as a unique niche. The adhesion of H. pylori to the gastric epithelium is not only crucial for successful colonization and pathogenesis but also essential for invasion into host cells. The study aimed to analyze whether H. pylori isolates carrying diverse virulence genotypes present an association in the rate of adherence to gastric epithelial cells (MKN۴۵).MATERIALS AND METHODSNineteen H. pylori strains with defined allelic variants of virulence factors, cagA, vacA, iceA, babA۲ and, sabA, were selected from the microbial collection of Foodborne and Waterborne Disease Research Center, Shahid Beheshti University of Medical Sciences. The response of H. pylori adherence to the MKN۴۵ cell line was analyzed after incubation for ۳ h. The host MKN-۴۵ cells were then lysed (brain heart infusion (BHI) broth, ۳۷ ºC, ۱۵ min) and adherent bacteria were counted on Brucella agar plates supplemented with ۱۰% horse serum and ۷% horse blood (microaerobic atmosphere, ۳۷ ºC, ۷ days), and then CFUs were enumerated. Finally, the correlation between the adhesion of studied strains to the MKN۴۵ cell line and their virulence genotypes was analyzed by SPSS statistical version ۱۷.RESULTS AND DISCUSSIONA wide range of adhesion potential was found among the studied H. pylori strains. The comparison of adhesion indices revealed that the greatest adherent strain to MKN-۴۵ cells was OC۲۹۱ (۴۱۲۵۰ CFU/well), followed by HC۱۳۶ (۲۷ CFU/well), and OC۳۰۹ (۲۷ CFU/well) as the lowest ones. There was no significant association between the adhesion index of studied strains and their virulence factors such as cagA, vacA, iceA, and adhesins (babA۲ and, sabA) (CagA+ ۷۹ % , CagA- ۲۱% , vacA s۱m۲ ۶۸% , vacA s۲m۲ ۲۶% , vacA s۱m۱ ۵.۲ / ice A۱+A۲ ۴۷% , ice A۱ ۳۶.۸%, ice A۲ ۵.۲%, ice A۱- ۱۰.۵۲% / sabA+ ۹۴.۷%, sabA- ۵.۲۶% / babA+ ۱۰۰%.CONCLUSIONConsidering, the results indicated that there was no significant association between the adhesion index of studied strains and their genotype of cagA, vacA, iceA and adhesins (babA, sabA). So, other virulence factors may be more important in the adhesion of H. pylori to the human gastric carcinoma cell line (MKN۴۵).

Helicobacter pylori, adherence assay, Virulence factor genotyping