Comparison of the Etest with agar dilution for antimicrobial susceptibility testing of Haemophilus ducreyi

Two methods for determining the sensitivity of Haemophilus ducreyi to antimicrobial agents were compared; an agar dilution method and the Etest. The MICs of seven antimicrobial agents; penicillin V, ampicillin, trimethoprim, tetracycline, chloramphenicol, erythromycin and ciprofloxacin were determined for 20 strains of H. ducreyi. The MICs determined with the Etest and with the agar dilution method, showed 86% agreement within one two-fold dilution. The Etest is a good alternative method to the agar dilution technique for antimicrobial susceptibility testing of H. ducreyi. Owing to its simplicity and good reproducibility, the test is well suited for routine use in clinical microbiology laboratories in developing countries.