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Research article - Peer-reviewed, 2022

High diversity of bla(NDM-1)-encoding plasmids in Klebsiella pneumoniae isolated from neonates in a Vietnamese hospital

Sriram, K. K.; Ekedahl, Elina; Ngoc Thi Bich Hoang; Sewunet, Tsegaye; Berglund, Bjorn; Lundberg, Ludwig; Nematzadeh, Shoeib; Nilsson, Maud; Nilsson, Lennart E.; Le, Ngai Kien; Dien Minh Tran; Hanberger, Hakan; Olson, Linus; Larsson, Mattias; Giske, Christian G.; Westerlund, Fredrik


Objectives: The carbapenemase-encoding gene bla(NDM-1) has been reported in Vietnam during the last 10 years, and bla(NDM)-producing Enterobacteriaceae are now silently and rapidly spreading. A key factor behind dissemination of bla NDM-1 is plasmids, mobile genetic elements that commonly carry antibiotic resistance genes and spread via conjugation. The diversity of bla(NDM-1)-encoding plasmids from neonates at a large Vietnamese hospital was characterized in this study.Methods: 18 fecal Klebsiella pneumoniae and Klebsiella quasipneumoniae isolates collected from 16 neonates at a large pediatric hospital in Vietnam were studied using optical DNA mapping (ODM) and next-generation sequencing (NGS). Plasmids carrying the bla(NDM-1) gene were identified by combining ODM with Cas9 restriction. The plasmids in the isolates were compared to investigate whether the same plasmid was present in different patients.Results: Although the same plasmid was found in some isolates, ODM confirmed that there were at least 10 different plasmids encoding bla(NDM-1) among the 18 isolates, thus indicating wide plasmid diversity. The ODM results concur with the NGS data. Interestingly, some isolates had two distinct plasmids encoding bla(NDM-1) that could be readily identified with ODM. The coexistence of different plasmids carrying the same bla(NDM-)1 gene in a single isolate has rarely been reported, probably because of limitations in plasmid characterization techniques.Conclusions: The plasmids encoding the bla(NDM-1) gene in this study cohort were diverse and may represent a similar picture in Vietnamese society. The study highlights important aspects of the usefulness of ODM for plasmid analysis. (c) 2021 The Author(s). Published by Elsevier Ltd.


Plasmids; Optical DNA mapping; Carbapenem; bla(NDM-1)

Published in

International Journal of Antimicrobial Agents
2022, volume: 59, number: 2, article number: 106496

Authors' information

Sriram, KK
Chalmers University of Technology
Ekedahl, Elina
Chalmers University of Technology
Hoang, Ngoc Thi Bich
Vietnam National Children’s Hospital
Sewunet, Tsegaye
Karolinska Institute
Berglund, Björn
Linköping University
Swedish University of Agricultural Sciences, Department of Molecular Sciences
Linköping University
Nematzadeh, Shoeib
Karolinska Institute
Nilsson, Maud
Linköping University
Nilsson, Lennart E
Linköping University
Le, Ngai Kien
Vietnam National Children’s Hospital
Tran, Dien Minh
Vietnam National Children’s Hospital
Hanberger, Hakan
Linkoping University
Olson, Linus
Karolinska Institutet
Larsson, Mattias
Karolinska Institutet
Giske, Christian G
Karolinska Institute
Westerlund, Fredrik
Chalmers University of Technology

Sustainable Development Goals

SDG3 Good health and well-being

UKÄ Subject classification

Public Health, Global Health, Social Medicine and Epidemiology
Cell and Molecular Biology

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