Susceptibility to fosfomycin of hospital strains isolated in Nantes (France). Frequency of mutation to resistance.

Susceptibility of 760 bacterial isolates to fosfomycin has been determined by the agar dilution method. The MICs of 364 strains have been determined by comparison of agar alone and agar plus glucose-6-phosphate. This later enhances the activity of fosfomycin. Lastly, we studied frequency of mutation toward resistance for 109 susceptible strains. We obtained 88 stable mutants.