1 Diagnostic Laboratory of Clinical Microbiology, Institute of Laboratory Medicine, Semmelweis University, Budapest,Hungary.
2 National Public Health Institute, Budapest,Hungary.
Acta Microbiol Immunol Hung. 2020 Mar 26;67(1):61-65. doi: 10.1556/030.2020.01152.
Our objective was to compare the activity ceftazidime-avibactam (C/A) and ceftolozane-tazobactam (C/T) against multidrug (including carbapenem) resistant Pseudomonas aeruginosa clinical isolates collected from six diagnostic centers in Hungary and to reveal the genetic background of their carbapenem resistance. Two hundred and fifty consecutive, non-duplicate, carbapenem-resistant multidrug resistant (MDR) P. aeruginosa isolates were collected in 2017. Minimal inhibitory concentration values of ceftazidime, cefepime, piperacillin/tazobactam, C/A and C/T were determined by broth microdilution method and gradient diffusion test. Carbapenem inactivation method (CIM) test was performed on all isolates. Carbapenemase-encoding blaVIM, blaIMP, blaKPC, blaOXA-48-like and blaNDM genes were identified by multiplex PCR. Of the isolates tested, 33.6% and 32.4% showed resistance to C/A and C/T, respectively. According to the CIM test results, 26% of the isolates were classified as carbapenemase producers. The susceptibility of P. aeruginosa isolates to C/A and C/T without carbapenemase production was 89% and 91%, respectively. Of the CIM-positive isolates, 80% were positive for blaVIM and 11% for blaNDM. The prevalence of Verona integron-encoded metallo-beta-lactamase (VIM)-type carbapenemase was 20.8%. NDM was present in 2.8% of the isolates. Although the rate of carbapenemase-producing P. aeruginosa strains is high, a negative CIM result indicates that either C/A or C/T could be effective even if carbapenem resistance has been observed.
我们的目的是比较头孢他啶-阿维巴坦（C/A）和头孢他啶-他唑巴坦（C/T）对来自匈牙利六个诊断中心的多药（包括碳青霉烯）耐药铜绿假单胞菌临床分离株的活性，并揭示其碳青霉烯类耐药的遗传背景。2017 年收集了 250 株连续、非重复的碳青霉烯类耐药多药耐药（MDR）铜绿假单胞菌分离株。采用肉汤微量稀释法和梯度扩散试验测定头孢他啶、头孢吡肟、哌拉西林/他唑巴坦、C/A 和 C/T 的最小抑菌浓度值。对所有分离株进行碳青霉烯失活法（CIM）试验。采用多重 PCR 方法鉴定 blaVIM、blaIMP、blaKPC、blaOXA-48 样和 blaNDM 基因编码的碳青霉烯酶。在所测试的分离株中，33.6%和 32.4%对 C/A 和 C/T 分别表现出耐药性。根据 CIM 试验结果，26%的分离株被归类为碳青霉烯酶产生菌。无碳青霉烯酶产生的铜绿假单胞菌分离株对 C/A 和 C/T 的敏感性分别为 89%和 91%。在 CIM 阳性分离株中，80%为 blaVIM 阳性，11%为 blaNDM 阳性。 Verona 整合子编码的金属β-内酰胺酶（VIM）型碳青霉烯酶的流行率为 20.8%。NDM 在 2.8%的分离株中存在。尽管产碳青霉烯酶铜绿假单胞菌菌株的比率较高，但 CIM 结果为阴性表明，即使观察到碳青霉烯类耐药，C/A 或 C/T 仍可能有效。
