TABLE 2.

Antimicrobial MIC ranges for E. coli ATCC 25922 at 24 and 48 h of incubation

Antimicrobial agent and incubation time (h)No. of occurrences at a MIC (μg/ml) ofa:% Of occurrences in rangeb
0.0020.0040.0080.0160.030.060.120.250.512481632641282565121,024
Gentamicin
    24000 4 122 98 16 00100
    48000 4 99 91 39 5098.7
Chloramphenicol
    2400 0 210 28 2 099.2
    4800 0 50 189 1 0100
Naladixic acid
    2400 2 143 91 4 00100
    48001 42 175 21 1099.2
Ciprofloxacin
    240 16 147 73 3100000098.3
    480 14 117 89 16 400000098.3
Levofloxacin
    24 1 159 76 22000000098.3
    48 1 116 103 15 3200000097.9
Doxycycline
    2400000 38 171 31 0000100
    4800000 2 105 125 8 0 00100
Tetracycline
    24000 26 139 75 0 0000100
    480001 67 118 54 000099.6
Streptomycin
    2400050 52 163 20 000097.9
    4800030 39 160 38 000098.8
Trimethoprim-sulfamethoxazole
    24 232 8 00000000100
    48 231 8 1000000099.6
  • a The absence of a value represents the limit of the MIC dilutions tested. Recommended QC ranges are represented in boldface characters.

  • b Percentages of results which fall within the recommended range (acceptable limit ≥95%).