Background: The prevalence of Helicobacter pylori antibiotic susceptibility in the Nepalese strains is untracked.\nWe determined the antibiotic susceptibility for H. pylori and analyzed the presence of genetic mutations associated\nwith antibiotic resistance in Nepalese strains.\nResults: This study included 146 consecutive patients who underwent gastroduodenal endoscopy in Kathmandu,\nNepal. Among 42 isolated H. pylori, there was no resistance to amoxicillin and tetracycline. In contrast, similar with\ntypical South Asian patterns; metronidazole resistance rate in Nepalese strains were extremely high (88.1 %, 37/42).\nClarithromycin resistance rate in Nepalese strains were modestly high (21.4 %, 9/42). Most of metronidazole\nresistant strains had highly distributed rdxA and frxA mutations, but were relative coincidence without a synergistic\neffect to increase the minimum inhibitory concentration (MIC). Among strains with the high MIC, 63.6 % (7/11) were\nassociated with frameshift mutation at position 18 of frxA with or without rdxA involvement. However, based on next\ngeneration sequencing data we found that one strain with the highest MIC value had a novel mutation in the form of\namino acid substituted at Ala-212, Gln-382, Ile-485 of dppA and Leu-145, Thr-168, Glu-117, Val-121, Arg-221 in dapF\naside from missense mutations in full-length rdxA. Mutations at Asn-87 and/or Asp-91 of the gyrA were predominantly\nin levofloxacin-resistant strains. The gyrB mutation had steady relationship with the gyrA 87ââ?¬â??91 mutations. Although\nthree (44.4 %) and two (22.2 %) of clarithromycin resistant strains had point mutation on A2143G and A2146G, we\nconfirmed the involvement of rpl22 and infB in high MIC strains without an 23SrRNA mutation.\nConclusions: The rates of resistance to clarithromycin, metronidazole and levofloxacin were high in Nepalese strains,\nindicating that these antibiotics-based triple therapies are not useful as first-line treatment in Nepal. Bismuth or\nnon-bismuth-based quadruple regimens, furazolidone-based triple therapy or rifabutin-based triple therapy may\nbecome alternative strategy in Nepal.
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