First Detection of blaNDM-5 Positive Escherichia coli ST224 in Myanmar: Insights into the Mobilome and Resistome via Oxford Nanopore Technology

Background: The global rise of Multidrug-Resistant (MDR) Escherichia coli (E. coli) represents a critical public health threat, severely compromising the treatment of infections. While Sequence Type 224 (ST224) is recognized as an emergent, high-risk lineage associated with extra-intestinal pathogenic E. coli (ExPEC) and MDR phenotypes globally, its specific genomic features and epidemiological footprint in Southeast Asia, particularly Myanmar, remain largely underexplored. Given Myanmar's vulnerability as an AMR hotspot, comprehensive genomic surveillance is critically leveraged. Method: A laboratory based cross sectional descriptive study conducted at Defense Services Medical Research Centre (DSMRC) during 20th January to 11th November 2025 and aimed to develop Oxford Nanopore Technologies (ONT) long-read sequencing, an early manifestation of this approach for bacterial genomic characterization in Myanmar. Five clinical MDR E. coli isolates (NMA_MM001) from (No.1) Defense Service General Hospital (DSGH) which were identified by Vitek2 analyzer were collected. Extracted DNA was sequenced on the MinION device at DSMRC. Bioinformatic analysis utilized the ONT EPI2ME platform for de novo assembly, followed by MLST, ResFinder, and PlasmidFinder analyses to characterize the isolate's resistome, mobilome, and virulence. Results: Out of five isolates, MDR E. coli (NMA_MM001) of ONT sequencing successfully generated a high-quality, near-closed assembly (N50: 4,911,841 bp, 5 contigs). MLST classified the isolate as ST224. This study confirmed a severe MDR phenotype, identifying blaDHA-1 (AmpC beta-lactamase), blaTEM-1, and two plasmid-mediated quinolone resistance genes (qepA4 and qnrB4). Crucially, the carbapenemase gene blaNDM-5 was identified, located on a highly mobile IncFII plasmid (pAMA1167-NDM-5). This constitutes the first report detailing the emergence of this NDM-5-producing ST224 lineage and its high genomic complexity in Myanmar. Conclusion: This study validates ONT long-read sequencing as an indispensable tool for resolving complex MDR genomes in resource-limited settings. The findings confirm the establishment of an MDR E. coli ST224 isolate in Myanmar carrying the critical blaNDM-5 carbapenemase gene on a highly mobile IncFII plasmid. This genomic information, identification of E. coli ST224, provides an urgent early warning of a highly resistant pathogen, mandating the immediate implementation of targeted infection control measures and regional One Health surveillance programs.