AUTHOR=Shao Chunhong , Hao Yingying , Wang Yong , Jiang Meijie , Jin Yan 

TITLE=Genotypic and Phenotypic Characterization of blaNDM–7-Harboring IncX3 Plasmid in a ST11 Klebsiella pneumoniae Isolated From a Pediatric Patient in China

JOURNAL=Frontiers in Microbiology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.576823

DOI=10.3389/fmicb.2020.576823

ISSN=1664-302X

ABSTRACT=<p>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 <italic>Klebsiella pneumoniae</italic> 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 <italic>bla</italic><sub>NDM–</sub><sub>7</sub>, <italic>bla</italic><sub>CTX–M–</sub><sub>15</sub>, <italic>qnrA</italic>, <italic>qnrB</italic>, and <italic>qnrS</italic>. The serotype of the isolated <italic>K. pneumoniae</italic> was assigned as K1, and it contained three virulence genes, including <italic>kfuBC</italic>, <italic>uge</italic>, and <italic>fim</italic>. The <italic>bla</italic><sub>NDM–</sub><sub>7</sub> gene was located on a conjugative IncX3 plasmid designated as pB14NDM-7. This plasmid was fully sequenced and compared with the available <italic>bla</italic><sub>NDM–</sub><sub>7</sub>-harboring IncX3 plasmids. pB14NDM-7 contained a conserved genetic context of <italic>ISkox3-umuD-IS26-ΔTn125</italic>-IS5-<italic>ΔTn125-IS3000-ΔTn2</italic>. pB14NDM-7 showed 99% nucleotide identity and the same genetic context with three <italic>bla</italic><sub>NDM–</sub><sub>7</sub>-harboring IncX3 plasmids obtained from <italic>Escherichia coli</italic> in China. Our results indicate that IncX3 plasmid may contribute to the prevalence of <italic>bla</italic><sub>NDM–</sub><sub>7</sub> in China. The high prevalence of NDM variants worldwide highlights the critical need for careful monitoring and control of the rapid dissemination of <italic>bla</italic><sub>NDM</sub>.</p>