Diagnostic Value of a Multiplex Real-Time PCR Assay for Rapid Detection and Typing of Gene-Encoding Metallo-p-Lactamase

摘要

Background: Metallo-P-Iactamase (MBL) in bacterial clinical isolates often confer resistance to most (3-lactam antimicrobial agents, the encoding genes of MBL could spread rapidly among clinical pathogens, and may lead to nosocomial infection and prevalence. Objective: The aim of this study was to perform a multiplex real-time PCR assay with high-resolution melting curve analysis for MBL-encoding genes (blamp, blaym, blaS0M, blaGlM, blasm and blaSPM) rapid detecting and typing, and evaluate the sensitivity, specificity and diagnostic accuracy of this assay. Methods and Results: A total of 63 Gram-negative isolates were tested with multiplex real-time PCR assay. The sensitivity, specificity, PPV and NPV of the multiplex real-time PCR assay for MBL-encoding genes detection were 100%, 93.74%, 93.75% and 100% respectively compared to positive products sequencing, and the area under the ROC curve (AUC) of multiplex realtime PCR assay was 0.970 (95%CI:0.922-1.000), indicating a high level of accuracy. The Agreement Kappa coefficient also verified the concordance between multiplex real-time PCR assay and MBL phenotype identification (Kappa = 0.841, p = 0.000). At the same time, the MBL-encoding genes have been typed and the whole experimentation can be completed in 3h. Conclusion: The accurate and timely detection and typing of MBL-encoding genes with multiplex real-time PCR assay could be helpful for nosocomial infection control and molecular epidemiological investigation.