Evaluation of carbapenem resistance genes in carbapenem-resistant Enterobacteriaceae isolates with GeneXpert® Carba-R panel.

Abstract

Introduction: Early detection of increases in carbapenem resistance among Enterobacteriaceae infections due to the widespread use of antibiotics is crucial. This study aimed to identify carbapenemase resistance genes in carbapenem-resistant Enterobacteriaceae isolates using the GeneXpert Carba-R Panel (Cepheid, Sunnyvale, USA).

Methodology: A total of 120 carbapenem-resistant Enterobacteriaceae isolates collected between January and June 2022 at the Microbiology Laboratory of Erzincan Mengücek Gazi Training and Research Hospital were included. The samples were cultured, and then incubated at 37 °C for 24-48 hours. Species-level identification and carbapenem resistance were determined using the VITEK MS and VITEK 2 automated systems (bioMérieux, Marcy l'Étoile, France). Carbapenemase gene detection was performed using the GeneXpert Carba-R assay, and antibiotic susceptibility testing was conducted according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines (version 12.0, 2022) using the VITEK 2 system.

Results: The most common carbapenemase genes detected were blaOXA-48 (65.0%), blaKPC (14.2%), blaNDM (4.2%), and blaVIM (1.7%). Additionally, combinations of resistance genes were observed in 3.3% (blaVIM + blaOXA-48 + blaKPC), 2.5% (blaOXA-48 + blaKPC), and 0.8% (blaVIM + blaKPC) of isolates. Klebsiella pneumoniae was the most frequently isolated species (116). All the isolates were resistant to ertapenem. The most effective antibiotics were colistin, imipenem, amikacin, and trimethoprim-sulfamethoxazole, in descending order of effectiveness.

Conclusions: The findings provide essential insights into alternative treatment options and surveillance of resistance to carbapenem-resistant Enterobacteriaceae. The results may also serve as a reference for future comparative studies and aid in developing effective infection control strategies.