Rapid Detection and Identification of Metallo-β-Lactamase-Encoding Genes by Multiplex Real-Time PCR Assay and Melt Curve Analysis

Abstract

ABSTRACT Metallo-β-lactamase enzymes (MβL) are encoded by transferable genes, which appear to spread rapidly among gram-negative bacteria. The objective of this study was to develop a multiplex real-time PCR assay followed by a melt curve step for rapid detection and identification of genes encoding MβL-type enzymes based on the amplicon melting peak. The reference sequences of all genes encoding IMP and VIM types, SPM-1, GIM-1, and SIM-1 were downloaded from GenBank, and primers were designed to obtain amplicons showing different sizes and melting peak temperatures ( T m ). The real-time PCR assay was able to detect all MβL-harboring clinical isolates, and the T m -assigned genotypes were 100% coincident with previous sequencing results. This assay could be suitable for identification of MβL-producing gram-negative bacteria by molecular diagnostic laboratories.