Table 8.

Drug-isolate combinations for which the modal MICs by Etest and broth microdilution differed by more than ± 1 twofold dilution and/or for which the difference in percent category agreement for the two methods was ≥25%a

DrugIsolateModal MIC (μg/ml) by:% Category agreement by:
EtestBrothEtestBroth
AmikacinMa 18022563288.9 (R)82.3 (S/I)
Mc 1866643266.7 (R)88.9 (S/I)
CefoxitinMa 18025126497.2 (R)97.2 (S/I)
Ma 18075123266.7 (R)100 (S/I)
Mf 135251264100 (R)86.1 (S/I)
CiprofloxacinMc 183132886.1 (R)83.3 (R)
ClarithromycinMf 135216494.4 (R)58.3 (R)
Mf 135910.25100 (S)100 (S)
ImipenemMa 180164897.2 (R)55.5 (S/I)
Ma 18026416100 (R)66.7 (R)
Ma 1807648100 (R)50 (R)
Mc 18146416100 (R)80.5 (R)
Mc 18316416100 (R)72.2 (R)
Mf 135164480.5 (R)91.7 (S/I)
Mf 135264472.2 (R)63.9 (S/I)
Mf 135364872.2 (R)58.3 (S/I)
Mf 135964855.5 (S/I)100 (S/I)
Sulfab Mf 13511275.0 (S)100 (S)
  • a Ma, M. abscessus; Mc,M. chelonae; Mf, M. fortuitum group; S, susceptible; I, intermediate; R, resistant.

  • b Sulfonamides tested were sulfamethoxazole combined with trimethoprim for Etest and sulfamethoxazole alone for broth microdilution.