mvaT mutation modifies the expression of the Pseudomonas aeruginosa multidrug efflux operon mexEF-oprN
mvaT mutation modifies the expression of the Pseudomonas aeruginosa multidrug efflux operon mexEF-oprN
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DOI：
10.1111/j.1574-6968.2005.00075.x
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发表时间：
2006-02-01
影响因子：
2.1
通讯作者：
Hamood, AN
中科院分区：
文献类型：
--
作者：
Westfall, LW;Carty, NL;Hamood, AN
铜绿假单胞菌携带多种药物外排操纵子，包括 mexEF-oprN，这有助于其对多种抗生素产生耐药性。 mvaT 影响多个铜绿假单胞菌基因的表达。在这项研究中，我们发现mvaT突变体PAO Delta mvaT比其亲本PAO1菌株对氯霉素和诺氟沙星具有更强的耐药性，但对亚胺培南更敏感；然而，与“典型”nfxC 型突变体相比，两者对氯霉素、诺氟沙星和亚胺培南的耐药性较低。两种菌株均不携带 mexT（mexEF-oprN 调节基因）中 nfxC 型突变体的缺失。 PAO Delta mvaT 中 mexEF-oprN 的表达增加了五到六倍，而 oprD 的表达减少了大约两倍。 mvaT 突变对其他多药耐药操纵子的表达没有影响，尽管它增加了几种 ATP 结合盒转运蛋白基因的表达。我们发现 mvaT 突变不会通过 mexT 或 mexS 影响 mexEF-oprN 表达。我们还探索了其他几种潜在的机制。
Pseudomonas aeruginosa carries several multidrug efflux operons, including mexEF-oprN, that contribute to its resistance to multiple antibiotics. mvaT affects the expression of several P. aeruginosa genes. In this study, we show that the mvaT mutant PAO Delta mvaT is more resistant than its parent PAO1 strain to chloramphenicol and norfloxacin but more sensitive to imipenem; yet both were less resistant to chloramphenicol, norfloxacin, and imipenem than 'typical' nfxC-type mutants. Neither strain carries the deletion described for nfxC-type mutants in mexT, the mexEF-oprN regulatory gene. Expression of mexEF-oprN is increased by five- to sixfold in PAO Delta mvaT, while the expression of oprD is reduced by approximately twofold. mvaT mutation had no effect on the expression of other multidrug resistance operons, although it increased the expression of several ATP-binding cassette transporter genes. We show that mvaT mutation does not affect mexEF-oprN expression through mexT or mexS. We also explored several other potential mechanisms.