1. Molecular epidemiological analysis of bla NDM-5-producing Klebsiella pneumoniae ST2407-K25 causing infection outbreaks in pediatric patients based on whole genome sequencing
- Author
-
Zhangrui Zeng, Caihong Ye, Jingchen Hao, Miran Tang, Xue Xiao, Chunxia Jian, Jinglan Guo, Yinhuan Ding, and Jinbo Liu
- Subjects
Klebsiella pneumoniae ,bla NDM−5 ,IncX3 ,ST2407_K25 ,Biofilm ,Pediatric infection control ,Therapeutics. Pharmacology ,RM1-950 ,Infectious and parasitic diseases ,RC109-216 ,Microbiology ,QR1-502 - Abstract
Abstract Background Pediatric patients are vulnerable to the threat of carbapenem-resistant Klebsiella pneumoniae (CRKP) due to their limited immunity and few available antibiotics. Especially when these pathogens exhibit hypervirulent phenotypes, they are often associated with poor clinical outcomes. Methods In this study, we investigated a CRKP outbreak in pediatric patients from 2019 to 2021 in a teaching hospital in China based on whole genome sequencing. We sequenced twenty-nine CRKP isolates isolated from unduplicated pediatric patients to understand their genetic relationships, virulence factors, resistance mechanisms, and transmission trajectories. Conjugation experiments were performed to evaluate the horizontal transfer ability of carbapenem resistance determinants in twenty-nine CRKP isolates. We then characterized these isolates for biofilm formation ability and serum resistance. Genetic relatedness, comparison of plasmids, and chromosomal locus variation of CRKP isolates were analyzed by bioinformatics. Results All the isolates were carbapenemase-producers harbouring bla NDM−5. Among them, twenty-eight isolates belonged to the ST2407 group, with the consistent capsular serotype K25. The virulence-related factors: ureA, fim, ybtA, irp1/irp2, and mrkA were prevalent in these isolates. Additionally, most CRKP isolates showed moderately adherent biofilm formation. Although the ST2407 clonal group did not exhibit serum resistance, the heterogeneous level of serum resistance was related to the disruption of oqxR. Conjugation and WGS revealed that the bla NDM−5 carried by the twenty-eight CRKP ST2407 isolates was located on nonconjugative IncX3 plasmids associated with deleting the T4SS-encoding genes. Clonal transmission of CRKP ST2407 in pediatric patients was suggested by the phylogenetic tree. Conclusions Our study provides evidence of the clonal spread of bla NDM−5-producing K. pneumoniae in pediatric patients and the necessity for the T4SS system for horizontal transfer of the IncX3 plasmid carrying bla NDM−5. Additionally, the disruption of oqxR may have affected the serum resistance of CRKP. The results of this study emphasize the importance of continuously monitoring for CRKP infection in pediatric patients to prevent recurrent infections.
- Published
- 2024
- Full Text
- View/download PDF