Comparison of antimicrobial susceptibility patterns of fifty-seven strains of Haemophilus ducreyi isolated in Amsterdam from 1978 to 1985.

The in-vitro activities of 16 antimicrobial agents were tested against 57 strains of Haemophilus ducreyi isolated in Amsterdam during an eight year period. The susceptibility patterns of the isolates from different years were compared. In the first four years more than 30% were beta-lactamase negative and showed MICs for tetracycline of 2 mg/l or less. From 1982 to 1985 all strains, except one, produced beta-lactamase and were tetracycline resistant. Furthermore, MICs for cefotaxime, sulphamethoxazole and trimethoprim increased. No changes were seen with cephradine, erythromycin, kanamycin, gentamicin, chloramphenicol, nalidixic acid, pipemidic acid, norfloxacin, pefloxacin or ciprofloxacin.