Multiplex PCR for rapid detection of genes encoding class A carbapenemases

Area of Science:

• Microbiology
• Molecular Biology
• Clinical Diagnostics

Background:

• Increasing reports of Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae in Korea.
• The modified Hodge test screens for Class A carbapenemase (CAC) but cannot differentiate carbapenemase types.
• Accurate identification of CAC types is crucial for effective therapy and preventing transmission.

Purpose of the Study:

• To develop and validate a novel multiplex PCR assay for detecting and differentiating Class A carbapenemase (CAC) genes.
• To provide a single-reaction method for identifying SME, IMI/NMC-A, KPC, and GES gene families.

Main Methods:

• Design of four primer pairs to amplify specific CAC gene families.
• Application of a multiplex PCR assay for simultaneous detection and differentiation.
• Analysis of fragment sizes to determine specific CAC gene types.

Main Results:

• The multiplex PCR assay successfully detected all tested CAC genes from four families (SME, IMI/NMC-A, KPC, GES).
• Differentiation of CAC gene types was achieved based on amplified fragment sizes.
• The assay demonstrated effectiveness in carbapenem-resistant strains that were metallo-β-lactamase nonproducers.

Conclusions:

• The developed multiplex PCR assay is a simple and useful tool for detecting and distinguishing CAC genes.
• This method supports accurate identification of carbapenemase types in clinical isolates.
• Facilitates optimal patient therapy and enhanced infection control strategies for carbapenem-resistant Enterobacteriaceae.