Comprehensive genomic epidemiology and antimicrobial resistance profiles of clinical Klebsiella pneumoniae species complex isolates from a tertiary hospital in Wenzhou, China (2019-2021).

Abstract

Background: The main issue of the Klebsiella pneumoniae species complex (KpSC) research in clinical settings is the accurate identification and differentiation of the closely related species within this complex. Moreover, the emergence and spread of carbapenem-resistant K. pneumoniae (CRKP) represent a significant public health threat due to limited treatment options and high mortality rates. Understanding the genetic basis of resistance and virulence is crucial for developing effective infection control strategies. In this work, the genomic epidemiology and antimicrobial resistance profile of KpSC isolates from Wenzhou, China, was investigated to fully understand the implications of the KpSC in clinical settings.

Methods: We conducted a comprehensive analysis of 156 clinical KpSC isolates collected from a tertiary hospital in China over a three-year period (2019-2021). Antimicrobial susceptibility testing was performed according to CLSI standards. Whole-genome sequencing (WGS) and subsequent bioinformatic analyses were conducted to identify resistance genes, plasmid types, and virulence factors. Phylogenetic relationships were determined using maximum-likelihood analysis.

Results: All CRKP isolates exhibited high levels of resistance to carbapenems, cephalosporins, and aminoglycosides. The most prevalent carbapenemase genes were bla_KPC-2 (100%), with significant associations between bla_KPC-2 and ST11. Phylogenetic analysis revealed considerable genetic diversity, with over 50 sequence types (STs) present. A subset of isolates harbored both resistance and hypervirulence genes, including rmpA, rmpA2, and siderophore systems, which were associated with potential higher pathogenesis.

Conclusion: This study provides novel insights into the molecular epidemiology of KpSC in Wenzhou, China, highlighting the coexistence of antimicrobial resistance and virulence factors in clinical isolates. The findings underscore the importance of continuous genomic surveillance and targeted therapeutic strategies to combat KpSC infections. Our research fills critical gaps in the current understanding of KpSC epidemiology in China and offers valuable data for global comparative studies, contributing to the development of effective infection control measures. Genomic surveillance in China thus provides crucial insights for local risk mapping and informs necessary adaptions for implementation of control strategies.