Identification of FosA8, a Plasmid-Encoded Fosfomycin Resistance Determinant from Escherichia coli, and Its Origin in Leclercia adecarboxylata

A plasmid-located fosfomycin resistance gene, fosA8, was identified from a CTX-M-15-producing Escherichia coliisolate recovered from urine. Identification of this gene was obtained by whole-genome sequencing. It encoded FosA8, which shares 79% and 78% amino acid identity with the most closely related FosA2 and FosA1 enzymes, respectively. The fosA8gene was located on a transferable 50-kb plasmid of IncN type encoding high-level resistance to fosfomycin.