Siqueira Vera Lúcia Dias, Cardoso Rosilene Fressatti, Caleffi-Ferracioli Katiany Rizzieri, Scodro Regiane Bertin de Lima, Fernandez Maria Aparecida, Fiorini Adriana, Ueda-Nakamura Tania, Dias-Filho Benedito Prado, Nakamura Celso Vataru
Postgraduate Program in Pharmaceutical Sciences, State University of Maringa, Maringá, Paraná, Brazil Department of Clinical Analysis and Biomedicine, State University of Maringa, Maringá, Paraná, Brazil.
Department of Clinical Analysis and Biomedicine, State University of Maringa, Maringá, Paraná, Brazil.
Antimicrob Agents Chemother. 2014 Jul;58(7):3957-67. doi: 10.1128/AAC.02584-13. Epub 2014 May 5.
The effect of a meropenem-ciprofloxacin combination (MCC) on the susceptibility of multidrug-resistant (MDR) Pseudomonas aeruginosa (MRPA) clinical isolates was determined using checkerboard and time-kill curve techniques. Structural changes and differential gene expression that resulted from the synergistic action of the MCC against one of the P. aeruginosa isolates (1071-MRPA]) were evaluated using electron microscopy and representational difference analysis (RDA), respectively. The differentially expressed, SOS response-associated, and resistance-associated genes in 1071-MRPA exposed to meropenem, ciprofloxacin, and the MCC were monitored by quantitative PCR. The MCC was synergistic against 25% and 40.6% of MDR P. aeruginosa isolates as shown by the checkerboard and time-kill curves, respectively. The morphological and structural changes that resulted from the synergistic action of the MCC against 1071-MRPA were a summation of the effects observed with each antimicrobial alone. One exception included outer membrane vesicles, which were seen in a greater amount upon ciprofloxacin exposure but were significantly inhibited upon MCC exposure. Cell wall- and DNA repair-associated genes were differentially expressed in 1071-MRPA exposed to meropenem, ciprofloxacin, and the MCC. However, some of the RDA-detected, resistance-associated, and SOS response-associated genes were expressed at significantly lower levels in 1071-MRPA exposed to the MCC. The MCC may be an alternative for the treatment of MDR P. aeruginosa. The effect of this antimicrobial combination may be not only the result of a summation of the effects of meropenem and ciprofloxacin but also a result of differential action that likely inhibits protective mechanisms in the bacteria.
采用棋盘法和时间杀菌曲线技术，测定了美罗培南 - 环丙沙星联合用药（MCC）对多重耐药铜绿假单胞菌（MRPA）临床分离株敏感性的影响。分别使用电子显微镜和代表性差异分析（RDA），评估了MCC对一株铜绿假单胞菌分离株（1071 - MRPA）协同作用所导致的结构变化和基因差异表达。通过定量PCR监测1071 - MRPA暴露于美罗培南、环丙沙星和MCC时差异表达的、与SOS反应相关的以及与耐药相关的基因。棋盘法和时间杀菌曲线结果显示，MCC对25%和40.6%的多重耐药铜绿假单胞菌分离株具有协同作用。MCC对1071 - MRPA协同作用所导致的形态和结构变化是每种抗菌药物单独作用时所观察到的效果之和。一个例外是外膜囊泡，环丙沙星处理后外膜囊泡数量增多，但MCC处理后显著减少。在暴露于美罗培南、环丙沙星和MCC的1071 - MRPA中，与细胞壁和DNA修复相关的基因存在差异表达。然而，在暴露于MCC的1071 - MRPA中，一些RDA检测到的、与耐药相关的以及与SOS反应相关的基因表达水平显著降低。MCC可能是治疗多重耐药铜绿假单胞菌的一种替代药物。这种抗菌药物联合使用的效果可能不仅是美罗培南和环丙沙星效果的叠加，还可能是通过差异作用抑制细菌保护机制的结果。
