In recent years, there has been a rapid dissemination of carbapenem resistant Enterobacteriaceae (CRE). This study aimed to compare phenotypic and molecular methods for detection and characterization of CRE isolates at a large tertiary care hospital in Saudi Arabia. This study was carried out between January 2011 and November 2013 at the King Khalid University Hospital (KKUH) in Saudi Arabia. Determination of presence of extended-spectrum beta-lactamases (ESBL) and carbapenem resistance was in accordance with Clinical and Laboratory Standards Institute (CLSI) guidelines. Phenotypic classification was done by the MASTDISCS(TM) ID inhibitor combination disk method. Genotypic characterization of ESBL and carbapenemase genes was performed by the Check-MDR CT102. Diversilab rep-PCR was used for the determination of clonal relationship. Of the 883 ESBL-positive Enterobacteriaceae detected during the study period, 14 (1.6%) isolates were carbapenem resistant. Both the molecular genotypic characterization and phenotypic testing were in agreement in the detection of all 8 metalo-beta-lactamases (MBL) producing isolates. Of these 8 MBL-producers, 5 were positive for blaNDM gene and 3 were positive for blaVIM gene. Molecular method identified additional blaOXA gene isolates while MASTDISCS(TM) ID detected one AmpC producer isolate. Both methods agreed in identifying 2 carbapenem resistant isolates which were negative for carbapenemase genes. Diversilab rep-PCR analysis of the 9 Klebsiella pneumoniae isolates revealed polyclonal distribution into eight clusters. MASTDISCS(TM) ID is a reliable simple cheap phenotypic method for detection of majority of carbapenemase genes with the exception of the blaOXA gene. We recommend to use such method in the clinical laboratory.

中文翻译：

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检测和鉴定抗碳青霉烯的肠杆菌科细菌的分子和表型方法的比较。

近年来，对耐碳青霉烯的肠杆菌科（CRE）的传播迅速。这项研究旨在比较表型和分子方法在沙特阿拉伯一家大型三级护理医院中对CRE分离物的检测和表征。这项研究于2011年1月至2013年11月在沙特阿拉伯的哈立德国王大学医院（KKUH）进行。根据临床和实验室标准协会（CLSI）指南确定是否存在广谱β-内酰胺酶（ESBL）和碳青霉烯抗药性。通过MASTDISCS TM ID抑制剂组合盘法进行表型分类。ESBL和碳青霉烯酶基因的基因型鉴定是通过Check-MDR CT102进行的。Diversilab rep-PCR用于确定克隆关系。在研究期间检测到的883个ESBL阳性肠杆菌科中，有14个（1.6％）分离株对碳青霉烯有抗药性。在检测所有8种金属β-内酰胺酶（MBL）产生菌株中，分子基因型特征和表型测试均一致。在这8个MBL产生子中，有5个对blaNDM基因呈阳性，而3个对blaVIM基因呈阳性。分子方法鉴定了另外的blaOXA基因分离株，而MASTDISCS（TM）ID检测到一个AmpC生产者分离株。两种方法均能鉴定出2个对碳青霉烯酶基因呈阴性的耐碳青霉烯分离株。对9株肺炎克雷伯菌的Diversilab rep-PCR分析显示多克隆分布为8个簇。MASTDISCS TM ID是一种可靠的简单廉价的表型方法，用于检测除blaOXA基因外的大多数碳青霉烯酶基因。我们建议在临床实验室中使用这种方法。