Co-Circulation of ST11-KL30 and ST11-KL64 Carbapenem-Resistant Klebsiella pneumoniae in Urumqi, Xinjiang, China: Molecular Epidemiology, Antimicrobial Resistance, and Virulence

Carbapenem-resistant Klebsiella pneumoniae (CRKP) and hypervirulent CRKP (hv-CRKP) are growing global threats with regional heterogeneity. We collected 93 non-duplicate CRKP isolates from a hospital in Urumqi, China, from January to December 2024. Antimicrobial susceptibility was tested using the VITEK 2 system, hypermucoviscosity was assessed by the string test, resistance and virulence genes were detected by polymerase chain reaction (PCR), and clonal lineages were determined by multilocus sequence typing (MLST) and capsular typing. Isolates were mainly from the intensive care unit (ICU) (36.56%) and respiratory department (31.18%), with sputum (51.62%) the predominant specimen type. Resistance rates to most β-lactams exceeded 97%. blaKPC was the predominant carbapenemase gene (94.62%), and hv-CRKP accounted for 54.84% of isolates. Sequence type 11 (ST11) was the dominant clone (89.25%), with K-locus types (KL30) (44 isolates) and KL64 (31 isolates) most common. ST11-KL30 exhibited significantly lower resistance rates to amikacin, gentamicin, trimethoprim-sulfamethoxazole, and tigecycline, and lower blaTEM carriage compared with ST11-KL64 (p < 0.05); it also showed a lower proportion of hv-CRKP and string test positivity. This study is the first to show that ST11-KL30 and ST11-KL64 co-circulate as dominant hv-CRKP-carrying clones in Urumqi, clarifying their resistance and phenotypic differences and providing key data for regional surveillance.