Helicobacter pylori resistance to metronidazole and its association with virulence factors in a Moroccan population

INTRODUCTION: surveillance data on Helicobacter pylori (H. pylori) antibiotic susceptibilities in Morocco are limited, despite resistance being the key factor in treatment failure. Virulence factors of H. pylori are associated with carcinogenesis and may be also associated with the efficacy of treatment. The aim of our study is to determine the prevalence of H. pylori metronidazole resistance in a Moroccan population infected with H. pylori and to study the impact of their virulence factors CagA and VacA on their resistance to metronidazole. METHODS: the susceptibility to metronidazole of 185 isolates was determined by PCR. The isolates were also genotyped for CagA and VacA genes by PCR. RESULTS: the metronidazole resistance rate was 62.70%. No association between resistance to metronidazole and social factors was detected. Regarding the virulence factors, we remarked that the moderate virulent strains s1/m2/i1/d1 with a CagA negative were the most resistant to metronidazole with a rate of 84% compared to the less virulent strains bearing the CagA negative VacA s2m2i2d2 genotype with a rate of 58% and the high virulent strains s1/m1/i1/d1-CagA positive with a rate of 47.06%. CONCLUSION: our study revealed a very high prevalence of resistance to metronidazole in our population. The resistance ability of H. pylori maybe affected by its virulence intensity. H. pylori eradication regimens should therefore be reevaluated in this setting.