Characterization of Carbapenem-Resistant Klebsiella pneumoniae in a Tertiary Hospital in the Eastern Coastal Region of Zhejiang, China: Detection of a Novel ST6853 Clone

Yijun Mo,1,* Jieyi Wang,1,* Min Zhai,2 Kaihang Lao,3 Jiani Han,1 Minhong Zhu,4 Xingbei Weng1 1Department of Laboratory Medicine, The First Affiliated Hospital of Ningbo University, Ningbo, Zhejiang, People’s Republic of China; 2Disease Test Laboratory, Ningbo International Travel Healthcare Center, Ningbo, Zhejiang, People’s Republic of China; 3Department of Laboratory Medicine, Wenzhou Medical University, Wenzhou, Zhejiang, People’s Republic of China; 4Department of Laboratory Medicine, Ninghai County Third Hospital, Ningbo, Zhejiang, 315010, People’s Republic of China*These authors contributed equally to this workCorrespondence: Xingbei Weng, Email [email protected]: Carbapenem-resistant Klebsiella pneumoniae (CRKP) is linked to hospital-acquired infections and associated with significant mortality rates, presenting a serious risk to public health. This research aimed to examine the in-hospital epidemiology and antimicrobial resistance of CRKP isolates, offering insights for the management and control of CRKP infections.Patients and Methods: In total, 76 carbapenem-resistant Klebsiella pneumoniae isolates were collected from inpatients at the First Affiliated Hospital of Ningbo University from May 2022 and February 2024. The isolates were mainly acquired from sputum, urine, secretions, and blood. Antimicrobial susceptibility testing was performed using the VITEK 2 Compact system or the Kirby-Bauer disk-diffusion method. In addition to susceptibility testing, phylogenetic analysis, and serotype analysis, whole genome sequencing was conducted to identify genes associated with antibiotic resistance.Results: Antimicrobial susceptibility testing showed that all 76 CRKP isolates were resistant to most common antibiotics. The CRKP isolates mainly carried Klebsiella pneumoniae carbapenemase, and the predominant gene was blaKPC-2. Homology analysis found that the major sequence type (ST) was ST11, as a single isolate was identified as an ST11 single-locus variant (ST6853), followed by ST15 and ST48. Serotype analysis found that the major serotype was K64, followed by K24 and K62.Conclusion: The CRKP isolates in our study exhibited resistance to the majority of commonly used antibiotics. The blaKPC-2 gene was identified as the predominant carbapenemase. The major ST of CRKP found in our hospital was ST11, with K64 and O2a being the prevalent predicted serotypes. These findings should prove useful for the control and management of CRKP infections, and provided guidance for clinical antibiotic therapy.Keywords: Klebsiella pneumoniae, carbapenem resistant, antimicrobial resistance, bacterial infections, nosocomial infections