Molecular epidemiological analysis and research on resistance and virulence of carbapenem-resistant Klebsiella pneumoniae in a tertiary hospital from 2016 to 2023.

PURPOSE

Carbapenem-resistant Klebsiella pneumoniae (CRKP) represents a significant global threat due to its high prevalence rates and limited therapeutic options. The primary objective of this study was to investigate the clinical distribution and molecular epidemiology of CRKP collected between 2016 and 2023 from a tertiary care hospital in northern China.

METHODS

Polymerase chain reaction (PCR) assays were used to identify resistance and virulence genes, while various assessments, including the string test and biofilm formation analysis, assessed CRKP's virulence. Multilocus sequence typing (MLST) and whole-genome sequencing were employed to elucidate strain classification and plasmid characteristics.

RESULTS

The study identified 100 unique CRKP strains, primarily isolated from neurosurgery and ICU, with sputum as the most common specimen type. The majority of strains harbored bla as the primary resistance mechanism. All CRKP strains harbored a minimum of four virulence genes, with entB, mrkD, fimH, and ybtS being most commonly detected across the isolates. Notably, 66 of 100 strains were classified as carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP). The prevailing sequence type (ST) observed was ST11, with serotype KL47 being most prevalent initially, subsequently supplanted by ST11-KL64. Specific strains harbored bla on IncFII-type plasmids, along with other resistance genes, such as bla. KP635_PlasmidB harbors multiple antibiotic resistance genes, and the sequence identity and coverage between KP635_PlasmidA and the NTUH-K2044 virulence plasmid are 99%, which contributes to the formation of a highly virulent and multidrug-resistant strain in KP635.

CONCLUSION

The emergence of high resistance and hypervirulence in CRKP requires vigilance, enhanced surveillance, and stringent infection control measures to limit its spread.