Persistence and Dissemination Capacities of a blaNDM-5-Harboring IncX-3 Plasmid in Escherichia coli Isolated from an Urban River in Montpellier, France

Abstract

To investigate the capacities of persistence and dissemination of blaNDM-5 within Escherichia coli and in aquatic environment, we characterized E. coli (sequence type 636) strains B26 and B28 isolated one month apart from the same urban river in Montpellier, France. The two isolates carried a pTsB26 plasmid, which sized 45,495 Kb, harbored blaNDM-5 gene and belonged to IncX-3 incompatibility group. pTsB26 was conjugative in vitro at high frequency, it was highly stable after 400 generations and it exerted no fitness cost on its host. blaNDM-5harboring plasmids are widely dispersed in E. coli all around the world, with no lineage specialization. The genomic comparison between B26 and B28 stated that the two isolates probably originated from the same clone, suggesting the persistence of pTsB26 in an E. coli host in aquatic environment.

Molecular characterization of blaNDM-harboring plasmids reveal its rapid adaptation and evolution in the Enterobacteriaceae

“…39.9% of the complete plasmids (n = 218) predicted to harbor oriT site, MOB and MPF simultaneously, which can be classified as conjugative. Although the typical oriT site were not predicted on the IncX3 plasmids (n = 179, 32.8%), its high conjugation transfer frequency has been confirmed in previous studies [18,19]. 30 different Inc-MOB-MPF combinations were observed and the top 3 combinations in quantity were highlighted and displayed with date in Supplementary Fig.…”

“…Here, we further explored the geographical dominance, host source specificity, bacterial genera, and dominant Inc type of plasmid for a better understanding of complex transfer modes of specific gene background. According to the observations of currently available data, IncX3 plasmid occupied a large fraction of the dominant cluster, and was identified in diverse geographical locations, host sources, and bacterial genera suggesting the wide spread and low fitness cost of IncX3 plasmid, as previous reported [7,18,19,33,34]. We hypothesized that IncX3 could be the dominant bla NDM -harboring plasmids in the next a few years.…”

Klebsiella Species and Enterobacter cloacae Isolates Harboring bla OXA-181 and bla OXA-48 : Resistome, Fitness Cost, and Plasmid Stability

“… K. pneumoniae genomes used were retrieved from the K. pneumoniae database ( https://bigsdb.pasteur.fr/klebsiella/ ). The genetic context of bla OXA-48 , bla OXA-181 , and bla DHA-1 and linear plasmid comparisons were generated and visualized using EasyFig v2.2.2 ( 43 ). Phylogeny of IncL plasmid from this study and 10 others retrieved from the NCBI database (last accessed February 2022) was generated with megaX v0.1 ( 44 ).…”

Adaptive Evolution Compensated for the Plasmid Fitness Costs Brought by Specific Genetic Conflicts

“…The ndm /IncX3 plasmid is thought to confer a low fitness cost that contributes to its worldwide occurrence [ 10 , 11 ]. However, some studies have also reported high fitness costs [ 12 , 13 ], though the variety of fitness costs and the mechanism involved remain unclear.…”

“…This cost in fitness has been attributed to plasmid properties, such as the number of copies, size of the plasmid, and related metabolic burden [ 4 , 5 , 6 , 7 ]. The ndm /IncX3 plasmid was considered to confer a low fitness cost because of its low copy number, minor metabolic burden, and stable genetic backbone [ 8 , 9 , 10 , 11 ]; however, high fitness costs have been reported in some E. coli strains [ 12 , 13 ]. The mechanism of the diversity of fitness costs while carrying the ndm /IncX3 plasmid remains unclear and is potentially unrelated to the general properties of the plasmid.…”