MicroScan WalkAway仪器对碳青霉烯类耐药肠杆菌科细菌检测能力的评价

Evaluation on the performance of MicroScan WalkAway in detecting carbapenem-resistant Enterobacteriaceae

目的评价MicroScanWalkAway 96 Plus(MSW)全自动微生物分析仪在碳青霉烯类耐药肠杆菌科细菌(CRE)鉴定与预警中的指导价值。方法同时用PCR法和MSW系统检测福建医科大学附属协和医院实验室保存的81株CRE。以纸片扩散法和PCR法为金标准,比较该分析仪器对CRE菌株鉴定及预测是否产碳青霉烯酶的可靠性。结果 MSW判定CRE的符合率为69.1%(56/81)。PCR检测有48株细菌携带碳青霉烯类耐药基因;仪器法检测这些菌株时,高级专家系统(AES)预测产碳青霉烯酶的灵敏度为93.8%,特异度为42.4%,阳性预测值为70.3%,阴性预测值为82.4%,准确度为72.8%。结论 MSW系统对CRE具有较强的检测能力。

Objective To investigate the performance of MicroScan WalkAway 96 Plus （MSW） system in detection of carbapenem-resistant Enterobacteriaceae （CRE）. Methods A total of 81 stock CRE strains were used in this study. Bacterial identification and antimicrobial susceptibility test were performed by MSW system. Beta-lactamases genes blaKPC, blaIMP blaVIM, blaoOXA-48 and blaNDM were amplified by PCR and subjected to sequencing analysis. Disk diffusion method and PCR were used as gold standard to evaluate the performance and reliability of MSW system in identifying carbapenem-resistant and carbapenemase- producing Enterobacteriaceae. Results Overall, 69.1% （56/81） of the Enterobacteriaceae strains were identified as CRE by the MSW system. The results of PCR showed that 48 strains were carbapenemase-producing Enterobacteriaceae. When carbapenemase- producing Enterobacteriaceae strains were identified by the instrument using an advanced expert system, the sensitivity was 93.8 % and specificity was 42.4%. The positive predictive value was 70.3 %, the negative predictive value was 82.4% and the predictive accuracy value was 72.8 %. Conclusions The MicroScan WalkAway 96 Plus system has shown good performance in detection of CRE.