Emergence of coexisting <i>bla</i> _NDM and <i>mcr-1</i> genes in <i>Escherichia coli</i> isolates from the guts of healthy individuals

This study reports isolation of <i>Escherichia coli</i> strains coharboring the critical resistance genes <i>bla</i>_NDM (carbapenemase) and <i>mcr-1</i> (colistin resistance) from the guts of healthy individuals (rural China). All seven isolates were extensively drug resistant, susceptible only to tigecycline and streptomycin. Crucially, both resistance genes were located on transferable plasmids, demonstrating potential for horizontal spread. Genomic analysis revealed diverse strains and plasmid types carrying these genes within mobile genetic contexts. This discovery identifies healthy human carriers as a significant reservoir for pan-resistant bacteria, posing severe public health challenges and necessitating urgent surveillance in endemic areas.