Evidence of transmission and dissemination of diverse blaNDM-5-producing Escherichia coli clones between refugee and host communities and their environment: a multicenter cross-sectional study

Abstract

The global spread of carbapenemase-producing Escherichia coli (CP-Ec) poses a significantpublic health threat, with particularly severe consequences for vulnerable populations in resource-limited settings. To address this, we conducted in-depth genetic analyses and examined the relatedness of CP-Ec isolates recovered from hospitalized patients, refugees, animals, water, and environmental sources within refugee camps and in marginalized host communities in Lebanon. Nineteen putative CP-Ec isolates, identifiedby MALDI-TOF MS and designated as community isolates, harbored either NDM (n = 17) or OXA-48-like (n = 2) carbapenemases. We used whole-genome sequencing (WGS) to characterize the resistomes and sequence types of these isolates. To further examine genetic relationships and transmission dynamics, we also analyzed publicly available (EnteroBase) CP-Ec genomes from Lebanon (n = 64) and across the globe (n = 447 recovered in 2022) alongside 31 additional clinical CP-Ec isolates from the same geographic region. The community isolates belonged to ST10, ST167, ST361, ST410, ST617, ST648, ST940, ST1284, and ST5842. Both community and clinical CP-Ec isolates carried multiple acquired antimicrobial resistance (AMR) genes and chromosomal mutations, with 82% harboring the blaNDM-5 gene. Core-genome SNP analysis showed that refugee isolates clustered with global CP-Ec genomes, highlighting their genomic relatedness and potential for geographical dissemination. Furthermore, integration of our data with previously reported Lebanese genomes demonstrated the spread of blaNDM-5-carrying E. coli across differenthosts and niches, emphasizing the complex interplay of AMR within the human-animal-environment interface. The coexistence of carbapenemase genes with mobile genetic elements that enable horizontal gene transfer raises concerns about the emergence of highly resistant and hypervirulent CP-Ec lineages, especially in vulnerable populations and settings.