Epidemiological and genomic characteristics of global blaNDM-carrying Escherichia coli.

Background: Escherichia. coli is the most frequent host for New Delhi metallo-β-lactamase (NDM) which hydrolyzes almost all β-lactams except aztreonam. The worldwide spread of blaNDM-carrying E. coli heavily threatens public health.

Objective: This study aimed to explore the global genomic epidemiology of blaNDM- carrying E. coli isolates, providing information for preventing the dissemination of such strains.

Methods: Global E. coli genomes were downloaded from NCBI database and blaNDM was detected using BLASTP. Per software was used to extract meta information on hosts, resources, collection data, and countries of origin from GenBank. The sequence types (STs) and distribution of antimicrobial resistance gene (ARG) were analyzed by CLC Workbench; Plasmid replicons, serotypes and virulence genes (VFs) were analyzed by submitting the genomes to the websites. Statistical analyses were performed to access the relationships among ARGs and plasmid replicons.

Results: Until March 2023, 1,774 out of 33,055 isolates collected during 2003-2022 were found to contain blaNDM in total. Among them, 15 blaNDM variants were found with blaNDM-5 (74.1%) being most frequent, followed by blaNDM-1 (16.6%) and blaNDM-9 (4.6%). Among the 213 ARGs identified, 27 blaCTX-M and 39 blaTEM variants were found with blaCTX-M-15 (n = 438, 24.7%) and blaTEM-1B (n = 1092, 61.6%) being the most frequent ones, respectively. In addition, 546 (30.8%) plasmids mediated ampC genes, 508 (28.6%) exogenously acquired 16 S rRNA methyltransferase encoding genes and 262 (14.8%) mcr were also detected. Among the 232 distinct STs, ST167 (17.2%) were the most prevalent. As for plasmids, more than half of isolates contained IncFII, IncFIB and IncX3. The VF terC, gad, traT and iss as well as the serotypes O101:H9 (n = 231, 13.0%), O8:H9 (n = 115, 6.5%) and O9:H30 (n = 99, 5.6%) were frequently observed.

Conclusions: The study delves into the intricate relationship between plasmid types, virulence factors, and ARGs, which provides valuable insights for clinical treatment and public health interventions, and serves as a critical resource for guiding future research, surveillance, and implementation of effective strategies to address the challenges posed by blaNDM-carrying E. coli. The findings underscore the urgent need for sustained global collaboration, surveillance efforts, and antimicrobial stewardship to mitigate the impact of these highly resistant strains on public health.