AUTHOR=Nguyen Quang Huy , Le Thi Thu Hang , Nguyen Son Thai , Nguyen Kieu-Oanh Thi , Quyen Dong Van , Hayer Juliette , Bañuls Anne-Laure , Tran Tam Thi Thanh 

TITLE=Large-scale analysis of putative plasmids in clinical multidrug-resistant Escherichia coli isolates from Vietnamese patients

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1094119

DOI=10.3389/fmicb.2023.1094119

ISSN=1664-302X

ABSTRACT=<sec><title>Introduction</title><p>In the past decades, extended-spectrum beta-lactamase (ESBL)-producing and carbapenem-resistant (CR) <italic>Escherichia coli</italic> isolates have been detected in Vietnamese hospitals. The transfer of antimicrobial resistance (AMR) genes carried on plasmids is mainly responsible for the emergence of multidrug-resistant <italic>E. coli</italic> strains and the spread of AMR genes through horizontal gene transfer. Therefore, it is important to thoroughly study the characteristics of AMR gene-harboring plasmids in clinical multidrug-resistant bacterial isolates.</p></sec><sec><title>Methods</title><p>The profiles of plasmid assemblies were determined by analyzing previously published whole-genome sequencing data of 751 multidrug-resistant <italic>E. coli</italic> isolates from Vietnamese hospitals in order to identify the risk of AMR gene horizontal transfer and dissemination.</p></sec><sec><title>Results</title><p>The number of putative plasmids in isolates was independent of the sequencing coverage. These putative plasmids originated from various bacterial species, but mostly from the <italic>Escherichia</italic> genus, particularly <italic>E. coli</italic> species. Many different AMR genes were detected in plasmid contigs of the studied isolates, and their number was higher in CR isolates than in ESBL-producing isolates. Similarly, the <italic>bla</italic><sub>KPC-2</sub>, <italic>bla</italic><sub>NDM-5</sub>, <italic>bla</italic><sub>OXA-1</sub>, <italic>bla</italic><sub>OXA-48</sub>, and <italic>bla</italic><sub>OXA-181</sub> β-lactamase genes, associated with resistance to carbapenems, were more frequent in CR strains. Sequence similarity network and genome annotation analyses revealed high conservation of the β-lactamase gene clusters in plasmid contigs that carried the same AMR genes.</p></sec><sec><title>Discussion</title><p>Our study provides evidence of horizontal gene transfer in multidrug-resistant <italic>E. coli</italic> isolates via conjugative plasmids, thus rapidly accelerating the emergence of resistant bacteria. Besides reducing antibiotic misuse, prevention of plasmid transmission also is essential to limit antibiotic resistance.</p></sec>