Department of Biotechnology and Laboratory Science in Medicine, National Yang-Ming University, Taipei 112, Taiwan.
J Antimicrob Chemother. 2013 Sep;68(9):1987-93. doi: 10.1093/jac/dkt148. Epub 2013 Apr 29.
To elucidate the role of the pcm-tolCsm operon in the multidrug resistance of Stenotrophomonas maltophilia.
The presence of the pcm-tolCsm operon was verified by RT-PCR. The phylogenetic relationship between the outer membrane proteins known to be involved in functional tripartite efflux in Escherichia coli, Pseudomonas aeruginosa and S. maltophilia was analysed. The contribution of TolCsm to resistance to a variety of compounds was investigated by susceptibility testing of the ΔtolCsm mutant. The role of pcm in the expression and function of tolCsm was assessed by quantitative real-time PCR and complementation assay.
The pcm and tolCsm genes formed an operon. TolCsm of S. maltophilia, OpmH of P. aeruginosa and TolC of E. coli formed a distinguishing phylogenetic TolC-like clade. TolCsm deletion increased the susceptibility of S. maltophilia KJ2 to several antimicrobial agents (aminoglycoside, macrolide, β-lactam, chloramphenicol, nalidixic acid, doxycycline and trimethoprim/sulfamethoxazole) and chemical compounds (acriflavine, carbonyl cyanide 3-chlorophenylhydrazone, crystal violet, fusaric acid, menadione, Paraquat, plumbagin, SDS and tetrachlorosalicylanilide). The in-frame deletion of pcm caused a polar effect on the expression of tolCsm, which compromised the resistance to amikacin and gentamicin. Nevertheless, the presence of the PCM protein made an insignificant contribution to the function of TolCsm in the resistance to amikacin and gentamicin.
The pcm-tolCsm operon makes a significant contribution to the multidrug resistance of S. maltophilia.
阐明 pcm-tolCsm 操纵子在嗜麦芽窄食单胞菌多药耐药中的作用。
通过 RT-PCR 验证 pcm-tolCsm 操纵子的存在。分析已知参与大肠杆菌、铜绿假单胞菌和嗜麦芽窄食单胞菌功能三联外排的外膜蛋白的系统发育关系。通过对ΔtolCsm 突变体的药敏试验研究 TolCsm 对多种化合物耐药性的贡献。通过定量实时 PCR 和互补试验评估 pcm 在 tolCsm 的表达和功能中的作用。
pcm 和 tolCsm 基因形成一个操纵子。嗜麦芽窄食单胞菌的 TolCsm、铜绿假单胞菌的 OpmH 和大肠杆菌的 TolC 形成了一个独特的系统发育 TolC 样分支。TolCsm 缺失增加了嗜麦芽窄食单胞菌 KJ2 对几种抗菌药物（氨基糖苷类、大环内酯类、β-内酰胺类、氯霉素、萘啶酸、强力霉素和磺胺甲噁唑）和化学化合物（吖啶黄素、羰基氰基 3-氯苯腙、结晶紫、 Fusaric 酸、亚硫酸氢钠甲萘醌、百草枯、白花丹素、SDS 和四氯水杨酰苯胺）的敏感性。pcm 的框内缺失对 tolCsm 的表达产生了极性影响，导致对阿米卡星和庆大霉素的耐药性降低。然而，PCM 蛋白的存在对 TolCsm 抵抗阿米卡星和庆大霉素的功能没有显著贡献。
pcm-tolCsm 操纵子对嗜麦芽窄食单胞菌的多药耐药性有重要贡献。
