Li X Z, Barré N, Poole K
Department of Microbiology and Immunology, Queen's University, Kingston, Ontario, Canada K7L 3N6.
J Antimicrob Chemother. 2000 Dec;46(6):885-93. doi: 10.1093/jac/46.6.885.
Of the Pseudomonas aeruginosa multidrug efflux systems, MexAB-OprM is expressed in wild-type cells, while MexCD-OprJ is not, and MexEF-OprN shows variable, strain-specific expression. In defined mutant strains, MexCD-OprJ expression increased with decreases in MexAB-OprM and was generally inversely related to MexAB-OprM expression. In so-called wild-type strains expressing MexEF-OprN, MexAB-OprM hyperexpression correlated with a decline in MexEF-OprN expression, while loss of MexAB-OprM was associated with increased expression of MexEF-OprN, also indicative of an inverse correlation between MexAB-OprM and MexEF-OprN expression. Still, the increases in MexCD-OprJ and MexEF-OprN failed to compensate for the loss of MexAB-OprM with respect to antibiotic resistance. Nonetheless, these data suggest that the overall complement of these MDR efflux systems is monitored and that alterations in the level of one efflux system may effect compensatory changes in the levels of the others.
在铜绿假单胞菌的多药外排系统中，MexAB - OprM在野生型细胞中表达，而MexCD - OprJ不表达，MexEF - OprN表现出可变的、菌株特异性的表达。在特定的突变菌株中，MexCD - OprJ的表达随着MexAB - OprM的减少而增加，并且通常与MexAB - OprM的表达呈负相关。在表达MexEF - OprN的所谓野生型菌株中，MexAB - OprM的过表达与MexEF - OprN表达的下降相关，而MexAB - OprM的缺失与MexEF - OprN表达的增加相关，这也表明MexAB - OprM与MexEF - OprN的表达呈负相关。然而，MexCD - OprJ和MexEF - OprN的增加在抗生素抗性方面未能补偿MexAB - OprM的缺失。尽管如此，这些数据表明这些多药耐药外排系统的整体组成是受到监测的，并且一个外排系统水平的改变可能会影响其他外排系统水平的代偿性变化。
