blaNDM-5 carried by a hypervirulent Klebsiella pneumoniae with sequence type 29

Antimicrobial Resistance & Infection Control 8, Article number: 140 (2019) | Download Citation

Abstract

Background

A carbapenem-resistant hypermucoviscous Klebsiella pneumoniae isolate was recovered from human sputum.

Methods

Whole genome sequencing of this isolate was carried out to reveal its clonal background, antimicrobial resistance determinants and virulence factors. Virulence assays were performed using wax moth larvae. The transfer of blaNDM-5 between bacterial strains was tested using conjugation. 59 genome assemblies of ST29 K. pneumoniae and 230 IncX3 plasmids regardless of the carriage of resistance gene were employed for phylogenetic analysis, respectively.

Results

The strain carried a virulence plasmid pVir-SCNJ1 bearing the virulence gene rmpAand exhibited a high virulence in wax moth. This hypervirulent strain belongs to sequence type 29 and carries blaNDM-5, which is located on a conjugative plasmid, designated pNDM5-SCNJ1, belonging to type IncX3. pNDM5-SCNJ1 was fully sequenced and shows high similarity with pNDM_MGR194, except some deletion inside the ISAba125 region. Phylogenetic analysis of IncX3 plasmids revealed that although blaNDM-5 can be evolved from blaNDM-1 via point mutations within some IncX3 plasmids, most of blaNDM-5-carrying IncX3 plasmids probably have acquired blaNDM-5 in multiple events.

Conclusions

In this study, we characterized a blaNDM-5-positive hypervirulent K. pneumoniae of sequence type 29 in China. Our results highlight the need for active surveillance on this lineage of carbapenem-resistant K. pneumoniae.