Genotypic and Phenotypic Characterization of bla NDM-7-Harboring IncX3 Plasmid in a ST11 Klebsiella pneumoniae Isolated From a Pediatric Patient in China

Chunhong Shao; Yingying Hao; Yong Wang; Meijie Jiang; Yan Jin

doi:10.3389/fmicb.2020.576823

Genotypic and Phenotypic Characterization of bla _NDM-7-Harboring IncX3 Plasmid in a ST11 Klebsiella pneumoniae Isolated From a Pediatric Patient in China

Front Microbiol. 2020 Oct 2:11:576823. doi: 10.3389/fmicb.2020.576823. eCollection 2020.

Authors

Chunhong Shao¹, Yingying Hao¹, Yong Wang¹, Meijie Jiang², Yan Jin¹

Affiliations

¹ Clinical Laboratory of Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China.
² Clinical Laboratory of Taian City Central Hospital, Tai'an, China.

Abstract

NDM-7, a variant of New Delhi metallo-beta-lactamases (NDM), has the highest carbapenem-hydrolyzing activity. NDM-7-producing enterobacteria have been reported in many countries. In this study, we reported NDM-7 production in ST11 Klebsiella pneumoniae isolated from a boy hospitalized in the pediatric intensive care unit of a teaching hospital in China. The isolate exhibited resistance to β-lactam antimicrobials, quinolones, and trimethoprim/sulfamethoxazole, and it harbored bla _NDM- ₇, bla _CTX-M- ₁₅, qnrA, qnrB, and qnrS. The serotype of the isolated K. pneumoniae was assigned as K1, and it contained three virulence genes, including kfuBC, uge, and fim. The bla _NDM- ₇ gene was located on a conjugative IncX3 plasmid designated as pB14NDM-7. This plasmid was fully sequenced and compared with the available bla _NDM- ₇-harboring IncX3 plasmids. pB14NDM-7 contained a conserved genetic context of ISkox3-umuD-IS26-ΔTn125-IS5-ΔTn125-IS3000-ΔTn2. pB14NDM-7 showed 99% nucleotide identity and the same genetic context with three bla _NDM- ₇-harboring IncX3 plasmids obtained from Escherichia coli in China. Our results indicate that IncX3 plasmid may contribute to the prevalence of bla _NDM- ₇ in China. The high prevalence of NDM variants worldwide highlights the critical need for careful monitoring and control of the rapid dissemination of bla _NDM.

Keywords: China; IncX3; K. pneumoniae; NDM-7; ST11.