Fosfomycin tromethamine susceptibility of outpatient urine isolates of Escherichia coli and Enterococcus faecalis from ten North American medical centres by three methods.

One hundred percent of 1097 Escherichia coli and 97.5% of 157 Enterococcus faecalis isolates from outpatient urine specimens at ten North American medical centres were susceptible to fosfomycin tromethamine. The Etest MICs correlated well with those of agar dilution. Disc diffusion zone diameters correlated well with MICs and supported the previously proposed zone diameter breakpoints for fosfomycin.