In-vitro activity of psychiatric drugs against Corynebacterium urealyticum (Corynebacterium group D2)

We tested the in-vitro activity of amoxycillin, amoxycillin/clavulanic acid, cefotaxime, gentamicin, trimethoprim-sulphamethoxazole, tetracycline, norfloxacin, ciprofloxacin, vancomycin, teicoplanin, clindamycin and five psychiatric drugs (chlorpromazine, sertraline, fluoxetine, paroxetine and risperidone) against 32 strains of Corynebacterium urealyticum. Resistance rates exceeded 90% for all antibiotics except glycopeptides, quinolones and tetracycline. Sertraline was the most active psychiatric drug. We tested the influence of sertraline on the activity of amoxycillin, amoxycillin/clavulanic acid, cefotaxime, gentamicin, trimethoprim-sulphamethoxazole, tetracycline and ciprofloxacin. We did not observe antagonism in any case. Sertraline enhanced the activity of ciprofloxacin and tetracycline against all strains (MIC decrease: 4-64-fold for ciprofloxacin, 2-32-fold for tetracycline).