The susceptibility of Aspergillus and Penicillium to recent antimycotics

: Fifty four mould strains (32 Aspergillus and 22 Penicillium) isolated from clinical materials were tested using dilution method. Two test media were used: Yeast Nitrogen Base (YNB) and Czapek Dox (CD). The following drugs were tested: amorolfine, cyclopirox, itraconazole, and terbinafine. In the dilution method, the drugs were tested at four contrentrations: 0.1 mg/l, 1 mg/l, 10 mg/l, and 100 mg/l. No matter which medium and/or drug was used, terbinafine turned out to be most effective. The drug at a conceatration of 1 mg/l inhibited 88.9% of the strains in the CD medium. The MIC values in the YNB medium varied from 0.1 mg/l through 100 mg/l, however, 50% of the strains were inhibited at 1 mg/l or less. Itraconazole revealed a fairly good in vitro antifungal action, particularly in the CD medium: 77.8% of the strains were inhibited at 10 mg/l or less. Aspergillus fumigatus and Aspergillus flavus were most susceptible to itraconazole. The MIC values of cyclopirox amounted to 100 mg/l for all of the strains in the CD medium but not in the YNB where they varied from 1 mg/l to 100 mg/l. Amorolfine was the least effective drug. Most of the strains were inhibited at a concentration of at least 100 mg/l. The findings give evidence that the susceptibility of Aspergillus and Penicillium to the particular drugs is different, and that the results are influenced by the test medium.