1Department of Pharmacodynamics and Biopharmacy, Faculty of Pharmacy, University of Szeged, Eötvös utca 6., 6720 Szeged, Hungary.
2Institute of Clinical Microbiology, Albert Szent-Györgyi Clinical Center, University of Szeged, Semmelweis utca 6., 6725 Szeged, Hungary.
Acta Microbiol Immunol Hung. 2020 Dec 1;67(4):209-215. doi: 10.1556/030.2020.01181.
Infections caused by carbapenem-resistant Enterobacterales (CRE) present an important therapeutic problem, as there are limited number of effective therapeutic alternatives available. In this study, phenotypic and genotypic methods were used to characterize carbapenemase-production and other resistance-determinants (AmpC and ESBL-production, efflux pump-overexpression) in 50 isolates (Klebsiella spp. n = 35, Escherichia coli n = 12 and Enterobacter cloacae complex n = 3) collected at the Albert Szent-Györgyi Clinical Center (University of Szeged) between 2014 and 2017. Minimum inhibitory concentrations of meropenem, sulfamethoxazole/trimethoprim, tigecycline, amikacin, moxifloxacin, colistin and fosfomycin were also determined. 24% of isolates were AmpC-producers, while 30% carried blaCTX-M ESBL-genes. Carbapenemase-genes were detected in 18 (36%) of the tested isolates: in 2 isolates blaNDM, in 6 isolates blaOXA-48-like and in 12 isolates, blaVIM was detected by PCR. The species-distribution for isolates positive for carbapenemase-genes was the following: Klebsiella pneumoniae n = 11, Klebsiella oxytoca n = 1, E. coli n = 5, E. cloacae complex n = 1. Efflux pump-overexpression based on the PAβN-screening agar was shown in n = 3 of the tested strains. In nine isolates (18%), carbapenemase and ESBL-genes were detected simultaneously. Highest levels of resistance were noted for fosfomycin (74%) and moxifloxacin (70%), while all isolates were susceptible to colistin. Among applied phenotypic tests in this study the modified carbapenem inactivation method (mCIM) proved to be the most accurate one compared to that of PCR results.
耐碳青霉烯肠杆菌科（CRE）引起的感染是一个重要的治疗问题，因为可用的有效治疗选择有限。在这项研究中，使用表型和基因型方法来描述 2014 年至 2017 年间在阿尔伯特·森特-哲尔吉临床中心（塞格德大学）收集的 50 株分离株（肺炎克雷伯菌 n = 35、大肠埃希菌 n = 12 和阴沟肠杆菌复合体 n = 3）中产碳青霉烯酶和其他耐药决定因素（AmpC 和 ESBL 产生、外排泵过表达）的特征。还测定了美罗培南、磺胺甲恶唑/甲氧苄啶、替加环素、阿米卡星、莫西沙星、多粘菌素和磷霉素的最低抑菌浓度。24%的分离株为 AmpC 生产者，而 30%携带 blaCTX-M ESBL 基因。在 18 株（36%）检测的分离株中检测到碳青霉烯酶基因：2 株携带 blaNDM 基因，6 株携带 blaOXA-48 样基因，12 株携带 blaVIM 基因通过 PCR 检测。对碳青霉烯酶基因阳性分离株的种分布为：肺炎克雷伯菌 n = 11、产酸克雷伯菌 n = 1、大肠埃希菌 n = 5、阴沟肠杆菌复合体 n = 1。基于 PAβN 筛选琼脂的外排泵过表达在 n = 3 株检测菌株中显示。在 9 株（18%）分离株中，同时检测到碳青霉烯酶和 ESBL 基因。对磷霉素（74%）和莫西沙星（70%）的耐药率最高，而所有分离株均对多粘菌素敏感。在本研究中应用的表型试验中，与 PCR 结果相比，改良碳青霉烯失活法（mCIM）被证明是最准确的方法。
