Identification and characteristics of a novel fosfomycin glutathione transferase, FosA12, from an MDR clinical isolate of Proteus vulgaris.

This study identifies fosA12, a novel chromosomally encoded fosfomycin resistance gene in a multidrug-resistant Proteus vulgaris clinical isolate. Through whole-genome sequencing, fosA12 was characterized, showing 64.23% homology with Pseudomonas aeruginosa's fosA. FosA12, a glutathione S-transferase, confers high-level fosfomycin resistance (MIC 512 μg/mL) via five critical residues. These findings highlight fosA12's role in resistance and the need for clinical surveillance.