Abstract:Objective To explore the clinical characteristics as well as molecular epidemiological features of resis-tance genes and virulence genes of carbapenem-resistant Klebsiella pneumoniae (CRKP) infection in a region, and provide scientific basis for the prevention, treatment, and epidemiological study of CRKP. Methods 60 non-repetitive CRKP strains isolated clinically from Puyang Oilfield General Hospital from November 2023 to September 2024 were analyzed retrospectively. Antimicrobial susceptibility testing was performed using VITEK 2 Compact automa-tic microbial analyzer, K-B disk diffusion method, and micro-broth dilution method. Mucus phenotype of bacterial strains was identified by string test. Carbapenemase was detected by carbapenemase inhibitor enhancement assay. Molecular features, such as multi-locus sequence typing (MLST), capsule serotypes, resistance genes, virulence genes, plasmid replication types of strains, as well as the genetic and evolutionary relationships of strains were determined by whole genome sequencing and bioinformatics analysis. Results CRKP strains were mainly isolated from elderly male hospitalized patients. Specimens were mostly from sputum (71.67%), mainly distributed in department of respiratory medicine (30.00%). All strains were highly resistant to multiple commonly used antimicrobial agents, only with high susceptibility rates to cefotaxime/avibactam, tigecycline, and polymyxin B (>60.00%). Two CRKP strains were positive for string test. 95.00% of the strains produced class A serine carbapenemase. All strains carried fluoroquinolone, phosphomycin, β-lactam, and aminoglycoside resistance genes; enterobactin, Esche-richia coli common pilus (ECP), and outer membrane protein-related virulence genes; as well as plasmids from the IncF plasmid family. Carbapenemase gene was mainly blaKPC-2 (95.00%), and the major capsule serotype was KL19 (43.33%). In MLST, ST11 (51.67%) was the dominant clone group, and ST11-KL62 (n=12) was the dominant subtype. Conclusion CRKP in this hospital is highly resistant to multiple commonly used antimicrobial agents, and its mechanism of resistance to carbapenems is mainly related to the presence of blaKPC-2 resistance gene. All strains have coexisting multiple resistance genes and virulence genes, and show a phenomenon of multi-clone transmission. ST11 is the dominant clone group, and ST11-KL62 is the main prevalent subclone type.