Background: Urinary tract infection (UTI) associated with Klebsiella pneumoniae poses a serious threat for inpatients. This study aimed to describe the genomic characteristics of K. pneumoniae causing UTI in a tertiary-care hospital in Beijing, China.
Methods: A total of 20 K. pneumoniae strains collected from 2020 to 2021 were performed whole-genome sequencing. The Antibiotic susceptibility of 19 common antimicrobial agents was tested against all strains. The multi-locus sequence types (MLSTs) and serotypes were determined from the WGS data. De novo assemblies were used to identify resistance and virulence genes. The presence and characteristics of the plasmids were detected using hybrid assembly of long and short-read data.
Results: These K. pneumoniae strains were clustered into nine sequence types (STs) and twelve K-serotypes. All the carbapenem-resistant K. pneumoniae (CRKP) strains acquired carbapenemase blaKPC-2 (n=7). Two CRKP strains exhibited increased resistance to Polymyxin B with MIC ≥ 4 mg/L due to insertion of an IS5-like sequence in the mgrB gene, and they were also involved in a transmission event in Intensive Care Unit. Long-read assemblies identified many plasmids co-carrying multiple replicons. Acquisition of a new IncM2_1 type blaCTX-M-3 positive plasmid was observed after transfer from ICU to neurovascular surgery by comparing the two strains collected from the same patient.
Conclusion: K. pneumoniae is a significant pathogen responsible for urinary tract infections. The ST11-KL47 strain, prevalent at our hospital, exhibits a combination of high drug resistance and hypervirulence. It is imperative to enhance ongoing genomic surveillance of urinary tract infection-causing pathogens.

Keywords: Antimicrobial resistance, Klebsiella pneumoniae, urinary tract infections