Utility of a novel multiplex TaqMan PCR assay for metallo-¦Â-lactamase genes plus other TaqMan assays in detecting genes encoding serine carbapenemases and clinically significant extended-spectrum ¦Â-lactamases

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• 作者：Rosemary Swayne ; Matthew J. Ellington ; Martin D. Curran ; Neil Woodford ; Sani H. Aliyu
• 关键词：Enterobacteriaceae ; Metallo-¦Â-lactamases ; Carbapenemases ; Extended-spectrum ¦Â-lactamases ; Cephalosporinases
• 刊名：International Journal of Antimicrobial Agents
• 出版年：2013
• 出版时间：October, 2013
• 年：2013
• 卷：42
• 期：4
• 页码：352-356
• 全文大小：367 K

文摘

Prompt detection of infections caused by Enterobacteriaceae that produce therapeutically important ¦Â-lactamases [metallo-¦Â-lactamases (MBLs), serine carbapenemases, acquired AmpC and CTX-M extended-spectrum ¦Â-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 ¦Â-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 ¦Â-lactamase groupings. The four TaqMan assays correctly identified the most clinically relevant acquired ¦Â-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 ¦Â-lactamase genes using these TaqMan assays. Amongst the urinary and blood culture isolates tested, 69 CTX-M-producers and 21 acquired AmpC ¦Â-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 ¦Â-lactamases, including carbapenemases.