Journal article icon

Journal article

Concurrent carriage of blaNDM plasmids in distinct Gram-negative bacterial species in the gut microbiota of pregnant mothers and neonates

Abstract:

Objectives New Delhi metallo-β-lactamase (NDM), a broad-spectrum carbapenemase, can disseminate via plasmids and is a major global healthcare challenge. The gut acts as a niche for the exchange of such genes. This study investigates the transmission dynamics of blaNDM-bearing plasmids among co-colonized bacterial species in pregnant mothers/neonates.

Methods Rectal isolates from mothers and neonates underwent antimicrobial susceptibility testing, detection of blaNDM variants, molecular typing and whole-genome/plasmid sequencing. Transmissibility of blaNDM was evaluated through conjugation.

Results Among mothers (n = 86) and sick neonates (n = 93) analysed, 17 were colonized with multiple carbapenem-resistant species; with nine patients colonized with multiple carbapenem-resistant Enterobacterales (CREs), primarily blaNDM-harbouring Escherichia coli and Klebsiella pneumoniae. Isolates were distinct and belonged to diverse sequence types, including epidemic clones (ST11/15/101/147/167/648). blaNDM variants (blaNDM-1 > blaNDM-5 > blaNDM-7 > blaNDM-4) were found to reside on large conjugative plasmids (46–271 kb), primarily belonging to IncFIA-FIB-FII replicons in these isolates. Comparison of blaNDM-plasmid backbones in co-colonized bacteria revealed high diversity and different blaNDM variants, while the immediate genetic environment of blaNDM was very similar. The diverse blaNDM plasmids indicated an independent acquisition of blaNDM instead of its transmission among co-colonized bacteria in individuals. However, in one neonate, co-colonized species (E. coli and K. pneumoniae) possessing blaNDM-5 showed similarities in plasmid backbones indicating possible transmission of blaNDM among these co-colonized species. In addition, similar blaNDM plasmid backbones were observed between isolates from different neonates.

Conclusions The high co-colonization of blaNDM-harbouring bacteria, some epidemic clones, calls for targeted intestinal CRE screening. However, exchange of such genes was very low in the gut, indicating independent acquisition of blaNDM.

Publication status:
Published
Peer review status:
Peer reviewed

Actions

Access Document

Files:
Publisher copy:
10.1093/jac/dkag229

Authors

More by this author
Institution:
University of Oxford
Division:
MPLS
Department:
Biology
Role:
Author
More by this author
Role:
Author
ORCID:
0000-0001-7518-9264


More from this funder
Funder identifier:
https://ror.org/0456r8d26
More from this funder
Funder identifier:
https://ror.org/0492wrx28


Publisher:
Oxford University Press
Journal:
Journal of Antimicrobial Chemotherapy More from this journal
Volume:
81
Issue:
8
Article number:
dkag229
Publication date:
2026-07-31
Acceptance date:
2026-06-16
DOI:
EISSN:
1460-2091
ISSN:
0305-7453
Pmid:
42535272


Language:
English
Keywords:
Pubs id:
2448260
Local pid:
pubs:2448260
Source identifiers:
W7172002775
Deposit date:
2026-08-14
ARK identifier:

Terms of use


Views and Downloads






If you are the owner of this record, you can report an update to it here: Report update to this record

TO TOP