Cambridge Public Health and Microbiology Laboratory, Public Health England, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK.
Int J Antimicrob Agents. 2013 Oct;42(4):352-6. doi: 10.1016/j.ijantimicag.2013.06.018. Epub 2013 Aug 9.
Prompt detection of infections caused by Enterobacteriaceae that produce therapeutically important β-lactamases [metallo-β-lactamases (MBLs), serine carbapenemases, acquired AmpC and CTX-M extended-spectrum β-lactamases (ESBLs)] is crucial for infection prevention and control and surveillance purposes, and, more contentiously, also for effective patient management. A novel TaqMan PCR assay was developed to detect genes encoding IMP, VIM, NDM, SPM, SIM and GIM MBLs. Published PCR assays for acquired genes encoding CTX-M ESBLs and AmpC β-lactamases were updated and adapted to the TaqMan format, respectively. A published TaqMan assay for serine carbapenemase genes was used. Assay specificity was tested using a panel of 59 isolates with known acquired genes from the four different β-lactamase groupings. The four TaqMan assays correctly identified the most clinically relevant acquired β-lactamase genes in the panel of 59 resistant Enterobacteriaceae, which included 3 VIM-, 7 NDM- and 12 IMP-producers. Consecutive, non-duplicate isolates of Enterobacteriaceae from 965 urinary and 343 blood cultures during 2010 were then screened for β-lactamase genes using these TaqMan assays. Amongst the urinary and blood culture isolates tested, 69 CTX-M-producers and 21 acquired AmpC β-lactamase-producers were identified; the CTX-M rate amongst blood culture isolates (9.3%) broadly reflects the UK national average. During the study period, one Klebsiella pneumoniae isolate producing an NDM carbapenemase was identified from a wound sample. The assays developed and/or used will enable the future surveillance and the rapid detection and appropriate early treatment of infections caused by Gram-negative bacteria producing clinically important β-lactamases, including carbapenemases.
检测产治疗相关β-内酰胺酶（金属β-内酰胺酶[MBL]、丝氨酸碳青霉烯酶、获得性 AmpC 和 CTX-M 超广谱β-内酰胺酶[ESBL]）的肠杆菌科感染的即时检测，对于感染预防和控制以及监测目的至关重要，更有争议的是，对于有效的患者管理也是如此。开发了一种新的 TaqMan PCR 检测方法，用于检测编码 IMP、VIM、NDM、SPM、SIM 和 GIM MBL 的基因。更新并分别改编了用于检测获得性 CTX-M ESBL 和 AmpC β-内酰胺酶编码基因的已发表 PCR 检测方法。使用了一种已发表的用于丝氨酸碳青霉烯酶基因的 TaqMan 检测方法。使用来自四个不同β-内酰胺酶分组的已知获得性基因的 59 个分离株的面板测试了检测方法的特异性。这四种 TaqMan 检测方法正确鉴定了 59 个耐药肠杆菌科分离株中最具临床相关性的获得性β-内酰胺酶基因，其中包括 3 个 VIM、7 个 NDM 和 12 个 IMP 产生菌。随后，使用这些 TaqMan 检测方法对 2010 年 965 份尿和 343 份血培养连续、非重复的肠杆菌科分离株进行β-内酰胺酶基因筛查。在所测试的尿和血培养分离株中，鉴定出 69 个 CTX-M 产生菌和 21 个获得性 AmpC β-内酰胺酶产生菌；血培养分离株中的 CTX-M 率（9.3%）大致反映了英国的全国平均水平。在研究期间，从一个伤口样本中分离出了一株产 NDM 碳青霉烯酶的肺炎克雷伯菌。开发和/或使用的检测方法将能够进行未来的监测，并快速检测和适当的早期治疗由产临床上重要β-内酰胺酶（包括碳青霉烯酶）的革兰氏阴性菌引起的感染。
