پروفايل ژنتيكي IS1004 در سويه هاي محيطي ويبريو كلرا جدا شده از آب هاي سطحي در ايران

Genetic Profile of IS1004 among Environmental Vibrio cholerae Isolated from Surface Water Sources in Iran

Abstract Background and objective: Vibrio cholerae includes toxigenic and non-toxigenic serotypes. Non O1-non O139 serotypes are non toxigenic and do not have any role in cholera epidemics or pandemics all over the world. Different typing methods are widely used for molecular epidemiological investigations of clinical and environmental V. cholerae. The aim of this study is to investigate the genetic relatedness of environmental isolates of this bacterium using IS1004 profiling as an epidemiological marker. Materials and methods: Environmental samples collected from surface water sources in Tehran and cultured of TCBS agar after filtration. One single colony on TCBS was selected and cultured on BHI agar after which the cultures were used for biochemical diagnostic tests and serogroupings. DNA was isolated and used for PCR confirmation of V. cholerae isolates and wbeT gene. Genetic relatedness of isolates was determined using southern blot analysis. Results: From total 20 environmental V. cholerae identified in this study no wbeT gene was detected for the isolates. A total of 7 different banding patterns were obtained for the isolates while other 13 isolates identified as non-typeable by this method. Comparison with our previous studies indicated no identical pattern with clinical V. cholerae isolates. Conclusion: Differences in the banding pattern of IS1004 revealed a high heterogeneity among the isolates from surface water sources in Iran while these heterogenic isolates do not have any genetic relatedness with clinical isolates.