Article ID: JJID.2023.213
In response to rising carbapenem-resistant Enterobacterales (CRE), our study investigated carbapenemase-producing Klebsiella pneumoniae and non-K. pneumoniae epidemiology and genetics. We collected 76 clinical Enterobacterales and four stool surveillance Escherichia coli isolates resistant to ertapenem or imipenem. Using PCR and DNA sequencing, we assessed carbapenemases, extended-spectrum β-lactamases, and AmpC β-lactamases. Molecular typing via pulsed-field gel electrophoresis (PFGE) and a conjugation experiment examining resistance gene transfer were conducted. Among the 80 isolates, 96.2% (77/80) harbored at least one carbapenemase gene, with blaOXA-48 in 87.5% (70/80). KPC-2 and IMP-8 carbapenemases were in 15.0% (12/80) and 22.5% (18/80) of the isolates, respectively, with 27.5% (22/80) having two or more carbapenemase genes. PFGE revealed diverse genotypes. PCR-based plasmid replicon typing identified IncA/C as the most prevalent type among K. pneumoniae isolates (26/29), and IncF and IncFIB among E. coli isolates (22/28). Conjugal transfer was successful for plasmids encoding OXA-48, CTX-M-3, CTX-M-14, CMY-2, and other β-lactamases, except the KPC-2 gene. In conclusion, our study highlights high carbapenemase prevalence in CRE, primarily OXA-48. Multiple carbapenemases within strains were common, and PFGE showed diverse patterns in these carbapenem-resistant isolates.
