[Comparison of susceptibilities for fosfomycin determined by various methods in clinical isolates in 2003 -2004].

Antimicrobial susceptibilities for fosfomycin (FOM), cephalexin, cefpodoxime, cefdinir, cefditren, ampicillin, sulbactam/ampicillin, imipenem (IPM), panipenem, meropenem (MEPM), biapenem, levofloxacin (LVFX), gatifloxacin, pazufloxacin, prulifloxacin and sulfamethoxazole/trimethoprim were determined by an agar dilution method using Mueller-Hinton agar (MHA) in Escherichia coli, Klebsiella spp., Serratia marcescens, Citrobacter spp., Enterobacter spp. and Proteus mirabilis, which were isolated from patients in 2003-2004. Those for FOM were determined by the agar dilution methods using MHA containing glucose-6-phosphate (G6P) under aerobic conditions, MHA under anaerobic conditions and nutrient agar under aerobic conditions. Those for FOM, LVFX, IPM and MEPM were also determined by an Etest method. The results by the agar dilution method showed that carbapenems had good antibacterial activities in all isolates, whereas MIC ranges for other antimicrobials were broad. Our results showed that the agar dilution method for FOM using MHA containing G6P under aerobic conditions provided reliable MICs in E. coli, which agreed with data previously reported. The results by the agar dilution method for LVFX, IPM and MEPM showed the high rate of agreement compared with those by the Etest method. In E. coli, the results for FOM by the agar dilution method using MHA containing G6P showed the high rate of agreement compared with the Etest results, although the rate was affected by bacterial species and culture conditions in various ways.