A study of rdxA gene deletion in metronidazole resistant and sensitive Helicobacter pylori isolates in Kerman, Iran

Introduction and objective: metronidazole (mtz) resistance in helicobacter pylori has been found to be associated with mutations in rdxa, a gene encoding an oxygen insensitive nadph nitroreductase, and enhanced by mutations in frxa a gene encoding a nad(p)h-flavin oxidoreductase. in this study, we examined the prevalence of rdxa deletion among local isolates of h. pylori. materials and methods: we tested 63 h. pylori isolates obtained from 191 patients referred to endoscopy unit of afzalipour hospital in kerman, iran, during 2009 for their susceptibility to common anti-h. pylori antibiotics using a modified disk diffusion test. then the metronidazole resistant and sensitive isolates were evaluated for deletion in rdxa gene by pcr methods and compared with each other. results: from 35 resistant h. pylori isolates in this study only 22.9% (8 isolates) detected with deletion rdxa gene. no rdxa deletion was detected in sensitive isolates. conclusion: according to rdxa deletion rates in this study, it seems that some other nitroreductases are involved in metronidazole activation or there are other metronidazole resistance mechanisms involved.