Molecular epidemiological analysis of blaNDM-5-producing Klebsiella pneumoniae ST2407-K25 causing infection outbreaks in pediatric patients based on whole genome sequencing.
Zhangrui Zeng, Caihong Ye, Jingchen Hao, Miran Tang, Xue Xiao, Chunxia Jian, Jinglan Guo, Yinhuan Ding, Jinbo Liu
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引用次数: 0
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 blaNDM-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 blaNDM-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 blaNDM-5-producing K. pneumoniae in pediatric patients and the necessity for the T4SS system for horizontal transfer of the IncX3 plasmid carrying blaNDM-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.
期刊介绍:
Annals of Clinical Microbiology and Antimicrobials considers good quality, novel and international research of more than regional relevance. Research must include epidemiological and/or clinical information about isolates, and the journal covers the clinical microbiology of bacteria, viruses and fungi, as well as antimicrobial treatment of infectious diseases.
Annals of Clinical Microbiology and Antimicrobials is an open access, peer-reviewed journal focusing on information concerning clinical microbiology, infectious diseases and antimicrobials. The management of infectious disease is dependent on correct diagnosis and appropriate antimicrobial treatment, and with this in mind, the journal aims to improve the communication between laboratory and clinical science in the field of clinical microbiology and antimicrobial treatment. Furthermore, the journal has no restrictions on space or access; this ensures that the journal can reach the widest possible audience.