Schweizer Herbert P
Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523-1682A, USA.
Genet Mol Res. 2003 Mar 31;2(1):48-62.
Pseudomonas aeruginosa is an opportunistic human pathogen exhibiting innate resistance to multiple antimicrobial agents. This intrinsic multidrug resistance is caused by synergy between a low-permeability outer membrane and expression of a number of broadly-specific multidrug efflux (Mex) systems, including MexAB-OprM and MexXY-OprM. In addition to this intrinsic resistance, these and three additional systems, MexCD-OprJ, MexEF-OprN and MexJK-OprM promote acquired multidrug resistance as a consequence of hyper-expression of the efflux genes by mutational events. In addition to antibiotics, these pumps export biocides, dyes, detergents, metabolic inhibitors, organic solvents and molecules involved in bacterial cell-cell communication. Homologues of the resistance-nodulation-division systems of P. aeruginosa have been found in Burkholderia cepacia, B. pseudomallei, Stenotrophomonas maltophilia, and the nonpathogen P. putida, where they play roles in resistance to antimicrobials and/or organic solvents. Despite intensive studies of these multidrug efflux systems over the past several years, their precise molecular architectures, their modes of regulation of expression and their natural functions remain largely unknown.
铜绿假单胞菌是一种机会性人类病原体，对多种抗菌药物表现出固有抗性。这种内在的多重耐药性是由低渗透性外膜与多种广泛特异性多药外排（Mex）系统（包括MexAB - OprM和MexXY - OprM）的表达协同作用引起的。除了这种固有抗性外，这些系统以及另外三个系统MexCD - OprJ、MexEF - OprN和MexJK - OprM，由于突变事件导致外排基因过度表达，从而促进获得性多重耐药性。除抗生素外，这些泵还能输出杀菌剂、染料、洗涤剂、代谢抑制剂、有机溶剂以及参与细菌细胞间通讯的分子。在洋葱伯克霍尔德菌、类鼻疽伯克霍尔德菌、嗜麦芽窄食单胞菌和非病原菌恶臭假单胞菌中发现了铜绿假单胞菌抗性-结瘤-分裂系统的同源物，它们在抗微生物和/或有机溶剂方面发挥作用。尽管在过去几年中对这些多药外排系统进行了深入研究，但其精确的分子结构、表达调控模式及其天然功能仍 largely unknown。 （注：原文中“remain largely unknown”直译为“在很大程度上仍然未知”，这里意译为“仍不清楚”更通顺，但需注意这是根据翻译要求尽量贴近原文进行的翻译，实际表达可能稍显生硬。）
