Fosfomycin is a decades-old antibiotic which is being revisited because of its perceived
activity against many extensively drug-resistant Gram-negative pathogens. FosA proteins
are Mn2+ and K+-dependent glutathione S-transferases which confer fosfomycin resistance
in Gram-negative bacteria by conjugation of glutathione to the antibiotic. Plasmid-borne fosA
variants have been reported in fosfomycin-resistant Escherichia coli strains. However, the
prevalence and distribution of fosA in other Gram-negative bacteria are not known. We …