Coșeriu Răzvan Lucian, Mare Anca Delia, Toma Felicia, Vintilă Camelia, Ciurea Cristina Nicoleta, Togănel Radu Ovidiu, Cighir Anca, Simion Anastasia, Man Adrian
Department of Microbiology, George Emil Palade University of Medicine, Pharmacy, Science and Technology Târgu Mureș, 540142 Târgu Mures, Romania.
Doctoral School of Medicine and Pharmacy, George Emil Palade University of Medicine, Pharmacy, Science and Technology Târgu Mureș, 540142 Târgu Mures, Romania.
Microorganisms. 2023 Aug 31;11(9):2211. doi: 10.3390/microorganisms11092211.
(1) Background: The purpose of the study was to describe the activity of efflux pumps in Multidrug-Resistant (MDR) clinical isolates of and to compare the carbapenem-resistance identification tests with PCR; (2) Methods: Sixty MDR were analyzed for detection of carbapenemase by disk diffusion inhibitory method, carbapenem inactivation method and Modified Hodge Test. Endpoint PCR was used to detect 7 carbapenemase genes (, , , , , , ) and for colistin resistance. The expression of A, B, C, E and X genes corresponding to the four main efflux pumps was also evaluated; (3) Results: From the tested strains, 71.66% presented at least one carbapenemase gene, with as the most occurring gene (63.3%). Compared with the PCR, the accuracy of phenotypic tests did not exceed 25% for . The efflux pump genes were present in all strains except one. In 85% of the isolates, an overactivity of A, B and mostly C was detected. Previous treatment with ceftriaxone increased the activity of C by more than 160 times; (4) Conclusions: In our MDR clinical isolates, the carbapenem resistance is not accurately detected by phenotypic tests, due to the overexpression of efflux pumps and in a lesser amount, due to carbapenemase production.
(1) 背景：本研究的目的是描述多药耐药（MDR）临床分离株中流出泵的活性，并将碳青霉烯耐药鉴定试验与聚合酶链反应（PCR）进行比较；(2) 方法：采用纸片扩散抑制法、碳青霉烯灭活法和改良 Hodge 试验对 60 株 MDR 进行碳青霉烯酶检测。采用终点 PCR 检测 7 种碳青霉烯酶基因（blaKPC、blaIMP、blaVIM、blaOXA-48、blaNDM、blaSIM、blaGES）以及黏菌素耐药基因 mcr。还评估了与四种主要流出泵相对应的 A、B、C、E 和 X 基因的表达；(3) 结果：在测试菌株中，71.66% 至少呈现一种碳青霉烯酶基因，其中 blaKPC 是最常见的基因（63.3%）。与 PCR 相比，blaKPC 的表型试验准确性不超过 25%。除一株外，所有菌株均存在流出泵基因。在 85% 的分离株中，检测到 A、B 以及主要是 C 的活性过高。先前使用头孢曲松治疗使 C 的活性增加了 160 倍以上；(4) 结论：在我们的 MDR 临床分离株中，由于流出泵的过表达以及少量碳青霉烯酶的产生，表型试验不能准确检测碳青霉烯耐药性。
