نتایج جستجو برای: ژن rdxa
تعداد نتایج: 15831 فیلتر نتایج به سال:
زمینه و اهداف: برای درمان زخم معده ناشی از هلیکوباکتر پیلوری، مترونیدازول یکی از آنتی بیوتیک های کلیدی است. هدف از این مطالعه تعیین میزان مقاومت سویه های هلیکوباکتر?پیلوری به مترونیدازول با روش دیسک دیفیوژن و ارزیابی نقش ژن rdxa در ایجاد مقاومت به مترونیدازول بود. روش بررسی: این مطالعه مقطعی - توصیفی در سال 1386 بر روی 263 بیمار مراجعه کننده به بیمارستان هاجر شهرکرد انجام شد. هلیکوباکتر پیلوری ...
زمینه و اهداف: برای درمان زخم معده ناشی از هلیکوباکتر پیلوری، مترونیدازول یکی از آنتی بیوتیک های کلیدی است. هدف از این مطالعه تعیین میزان مقاومت سویه های هلیکوباکتر?پیلوری به مترونیدازول با روش دیسک دیفیوژن و ارزیابی نقش ژن rdxA در ایجاد مقاومت به مترونیدازول بود. روش بررسی: این مطالعه مقطعی - توصیفی در سال 1386 بر روی 263 بیمار مراجعه کننده به بیمارستان هاجر شهرکرد انجام شد. هلیکوباکتر پیلوری...
Helicobacter pylori is a human-pathogenic bacterial species that is subdivided geographically, with different genotypes predominating in different parts of the world. Here we test and extend an earlier conclusion that metronidazole (Mtz) resistance is due to mutation in rdxA (HP0954), which encodes a nitroreductase that converts Mtz from prodrug to bactericidal agent. We found that (i) rdxA gen...
Helicobacter pylori is a globally important and genetically diverse gastric pathogen that infects most people in developing countries. Eradication efforts are complicated by antibiotic resistance, which varies in frequency geographically. There are very few data on resistance in African strains. Sixty-four Gambian H. pylori strains were tested for antibiotic susceptibility. The role of rdxA in ...
Resistance to metronidazole (Mtz) in Helicobacter pylori is a major problem worldwide, especially in developing countries. Alterations in Mtz nitroreductase enzymes, such as oxygen-insensitive NADPH nitroreductase (RdxA) and NADPH flavin oxidoreductase (FrxA), are the major contributing factors for this resistance. In this study, rdxA and frxA were amplified, sequenced, and analyzed in 34 Mtz-r...
Mutations in Helicobacter pylori rdxA gene sequences may not contribute to metronidazole resistance.
Metronidazole resistance in Helicobacter pylori reportedly occurs by mutational inactivation of the oxygen-insensitive nitroreductase gene rdxA. Nucleotide sequences of rdxA were determined in a set of 46 isolates from 19 dyspeptic patients from the UK. The study set comprised matched isolates that were either metronidazole susceptible (four) or mixed metronidazole susceptible and metronidazole...
We previously reported that inactivation of rdxA and/or frxA converted Helicobacter pylori from metronidazole sensitive to metronidazole resistant. To examine the individual roles of rdxA and frxA in the development of metronidazole resistance in H. pylori, we examined the status of rdxA and frxA from 12 pairs of metronidazole-sensitive and -resistant H. pylori isolates obtained following unsuc...
The relative importance of the frxA and rdxA nitroreductase genes of Helicobacter pylori in metronidazole (MTZ) susceptibility and resistance has been controversial. Jeong et al. (J. Bacteriol. 182:5082--5090, 2000) had interpreted that Mtz(s) H. pylori were of two types: type I, requiring only inactivation of rdxA to became resistant, and type II, requiring inactivation of both rdxA and frxA t...
Metronidazole (Mtz) is a critical ingredient of modern multidrug therapies for Helicobacter pylori infection. Mtz resistance reduces the effectiveness of these combinations. Although null mutations in a rdxA gene that encodes oxygen-insensitive NAD(P)H nitroreductase was reported in Mtz-resistant H. pylori, an intact rdxA gene has also been reported in Mtz-resistant H. pylori, suggesting that a...
In the photosynthetic bacterium Rhodobacter sphaeroides, a chromosomal gene, rdxA, which encodes a 52-kDa protein, was found to be homologous to fixG, the first gene of a Rhizobium meliloti nitrogen fixation operon on the pSym plasmid (D. Kahn, M. David, O. Domergue, M.-L. Daveran, J. Ghai, P. R. Hirsch, and J. Batut, J. Bacteriol. 171:929-939, 1989). The deduced amino acid sequences of RdxA an...
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