Differential gene expression in a Bacteroides fragilis metronidazole-resistant mutant
Differential gene expression in a Bacteroides fragilis metronidazole-resistant mutant
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DOI：
10.1093/jac/dkh256
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发表时间：
2004-07-01
影响因子：
5.2
通讯作者：
Smith, CJ
中科院分区：
文献类型：
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作者：
Diniz, CG;Farias, LM;Smith, CJ
目的：目前的工作集中在一个自发的脆弱类杆菌突变体的分子变化选择低浓度的甲硝唑作为适应性反应的drug.Methods：甲甲硝唑耐药菌株来自B。通过在药物存在下使用0-4 mg/L梯度板传代来选择脆弱菌ATCC 25285。使用组合的蛋白质组学鉴定差异表达的蛋白质，通过双向电泳和选择突变分析，通过单交叉插入和等位基因交换，我们已经确定了基因参与适应性反应metronidazole.Results：有显着的变化，耐药菌株的蛋白质谱。这些变化似乎影响了广泛的代谢蛋白，包括乳酸脱氢酶（上调）和黄素氧还蛋白（下调），这可能涉及电子转移反应。此外，酶的活性受损的谷氨酸-铁氧还蛋白氧化还原酶（PorA）复合物。突变株缺乏的基因flavodoxin和PorA是不太敏感的甲硝唑比敏感的父母，和一个双flavodoxin/PorA突变体甚至更少的敏感性，但没有一个突变体的耐药性作为自发的甲硝唑耐药strain.Conclusions：总体而言，数据表明，有全球性的变化调节的生理学的甲硝唑耐药菌株。此外，黄素氧还被认为是B中甲硝唑敏感性的重要因素。脆弱的。
Objectives: The current work focused on molecular changes in a spontaneous Bacteroides fragilismutant selected by low concentrations of metronidazole as an adaptive response to the drug.Methods: A metronidazole-resistant strain derived from B. fragilis ATCC 25285 was selected by passage in the presence of drug using 0-4 mg/L gradient plates. Using a combination of proteomics for identification of differentially expressed proteins by two-dimensional electrophoresis and selected mutational analyses by single cross-over insertion and an allelic exchange, we have identified genes involved in the adaptive response to metronidazole.Results: There are significant changes in the protein profiles of resistant strains. These changes appeared to affect a wide range of metabolic proteins including lactate dehydrogenase (up-regulated) and flavodoxin (down-regulated), which may be involved in electron transfer reactions. Also, the enzymic activity of the pyruvate-ferredoxin oxidoreductase (PorA) complex was impaired. Mutant strains lacking the genes for flavodoxin and PorA were less susceptible to metronidazole than the sensitive parent, and a double flavodoxin/PorA mutant had even less susceptibility but none of the mutants were as resistant as the spontaneous metronidazole-resistant strain.Conclusions: Overall, the data indicated that there were global changes in the regulation of the physiology of the metronidazole-resistant strain. In addition, flavodoxin was identified as an important contributor to metronidazole sensitivity in B. fragilis.