Osong Public Health Res Perspect.  2020 Feb;11(1):53-59. 10.24171/j.phrp.2020.11.1.08.

Development of a Two Triplex Real-Time Polymerase Chain Reaction for Rapid Detection of Six Carbapenemase Genes in Enterobacteriaceae

• Choi JA
• Bae SM
• Kim JW
• Lee KJ

• KMID: 2502111
• DOI: http://doi.org/10.24171/j.phrp.2020.11.1.08

Abstract

Carbapenem resistance is a serious clinical and public health threat. Carbapenemase can confer carbapenem resistance, and most carbapenemase genes are plasmid encoded so resistance can easily spread. In this study, we aimed to develop a novel system based on the TaqMan platform for the rapid detection of 6 clinically prevalent carbapenemase genes: Klebsiella pneumoniae carbapenemase, New Delhi metallo-β-lactamase, oxacillinase, imipenem-hydrolyzing, Verona integron-encoded metallo-β-lactamase, and Guiana extended-spectrum β-lactamase.

The triplex assay was verified by testing genomic DNA of 6 carbapenemase-producing Klebsiella pneumoniae. It was validated with a blinded panel of 310 Enterobacteriaceae isolates, including 225 carbapenemase-producers and 85 non-producers, by direct colony triplex real-time polymerase chain reaction (PCR). The real-time PCR was performed using the ABI 7500 fast instrument (Applied Biosystems, CA, USA) and specific primers for each carbapenemase target were designed to include modified peptide-nucleic acid oligonucleotides.

No amplification was detected among the negative samples. The result showed 100% concordance with the genotypes previously identified. The entire assay, including DNA extraction and real-time PCR, was completed within 2 hours.

The newly developed triplex real-time PCR assay was useful for the rapid, accurate and simultaneous detection of 6 carbapenemase genes in Enterobacteriaceae, suggesting its potential to allow an early decision on the appropriate treatment, management, and prevention of the spread of resistant infections in hospitals.

Keyword

carbapenemase; real-time PCR; triplex PCR