Evaluation on the performance of MicroScan WalkAway in detecting carbapenem-resistant Enterobacteriaceae / 中国感染与化疗杂志

ABSTRACT

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, blaOXA-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.