TABLE 1

In vitro susceptibilities to fosfomycin of E. coli and Klebsiella spp. clinical isolates from patients with UTIs at pH 6.0 and 7.0a

MicroorganismNo. of strainspH of testNo. of isolates with the following MIC (μg/ml):MIC (mg/liter)% of isolates
CLSIEUCAST
0.250.51248163264128256512>51250%90%RangeSIRSR
Escherichia coli1587.036154196103114161 to >5129811973
6.09635212135211280.5 to >512991982
Klebsiella spp.b877.02223212217256>51216 to >51252669595
6.0236152619791285128 to >5123030401387
  • a −, no isolate; S, susceptible; I, intermediate susceptibility; R, resistant; CLSI, Clinical and Laboratory Standards Institute interpretative criteria (susceptible, MIC of ≤64 μg/ml; intermediate, MIC of 128 μg/ml; resistant, MIC of ≥256 μg/ml; EUCAST, European Committee on Antimicrobial Susceptibility Testing interpretative criteria (susceptible, MIC of ≤32 μg/ml; resistant, MIC of ≥32 μg/ml).

  • b The species isolated included Klebsiella pneumoniae (n = 81) and K. oxytoca (n = 6).