Drug Resistance Genes and Molecular Epidemiological Characteristics of Carbapenem-Resistant Klebsiella pneumonia

BACKGROUND: The global prevalence of carbapenem-resistant Klebsiella pneumoniae (CRKP) has become a serious challenge for nosocomial infection and attracted worldwide attention. This study explored the drug resistance genes and molecular characteristics for CRKP, providing a reference for nosocomial prevention and control. METHODS: A total of 42 CRKP isolates were collected from the First Affiliated Hospital of Gannan Medical University (Ganzhou, China) from January 2018 to February 2021. The drug resistance of CRKP was tested by the VitekII Compact system. Drug resistance gene expression was detected by poly-merase chain reaction (PCR), and molecular typing was performed by pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST). RESULTS: All the 42 CRKP isolates were multi-drug resistant. Among them, 35 isolates (83.3%) produced bla(KPC-2) and 12 isolates (28.6%) produced bla(NDM-1). The detection rate of bla(IMP-4) and bla(OXA-48) was 2.4% (1/42), respectively. Twelve isolates (28.6%) carried both bla(KPC-2) and bla(NDM-1), one isolate (2.4%) carried both bla(KPC-2) and bla(IMP-4), and one isolate (2.4%) carried bla(KPC-2), bla(NDM-1) and bla(OXA-48). A variety of other extended-spectrum beta-lactamases (ESBLs) were also detected. All 42 isolates carried bla(SHV) and bla(CTX-M-1), 27 isolates (64.3%) carried bla(TEM) and 12 isolates (28.6%) carried bla(CTX-M-9). The MLST data classified the 42 CRKP isolates into 11 sequence types, mainly ST11, accounting for 61.9% (26/42), of which 92.3% of isolates (24/26) carrying bla(KPC-2). The PFGE results demonstrated that the 42 CRKP isolates could be divided into 20 clusters A-T, with cluster A (26.2%, 11/42) and cluster H (21.4%, 9/42) dominating, which were all ST11. CONCLUSION: The CRKP isolates were severely multi-drug resistant, and the main resistant gene was bla(KPC-2) production, carrying multiple ESBLs genes simultaneously. The MLST and PFGE revealed that the ST11-bla(KPC-2) Klebsiella pneumoniae was the main clonotype. Our findings may offer help to antibiotics selection and nosocomial infection prevention and control.