Emergence of Plasmid-Mediated Fosfomycin-Resistance Genes among Escherichia coli Isolates, France

FosA, a glutathione S-transferase that inactivates fosfomycin, has been reported as the cause of enzymatic resistance to fosfomycin. We show that multiple lineages of FosA-producing extended spectrum β-lactamase Escherichia coli have circulated in France since 2012, potentially reducing the efficacy of fosfomycin in treating infections with antimicrobial drug–resistant gram-negative bacilli.