Figure 2.

In vitro synergistic antimicrobial activity of drug combinations against Aspergillus fumigatus. (A) Plate spotting of domiphen and itraconazole against four strains of A. fumigatus. The concentration of A. fumigatus in the first, second and third columns was 10⁸, 10⁷, and 10⁶ CFU/mL, respectively. (B) Size of colony diameter after drug inhibition. Combination therapy for A. fumigatus is more effective than monotherapy. D+I, Domiphen+Itraconazole. (C) Determination of the antimicrobial activity of domiphen and itraconazole against four A. fumigatus strains. “+” represents the administration of 1/2 × MIC concentration of the single drug; or 1/4 × MIC concentration of combined drugs. “−” represents administration of the same volume of sterile water. After 36 h of treatment, the number of CFU was measured. Data from six replicates were collected to obtain mean log CFU values. Statistical analysis was performed to determine significant differences between the combined treatments and the single compounds. ^***p < 0.001; ^****p < 0.0001 according to unpaired two-tailed t-test. (D) Growth curves of domiphen, itraconazole and the combination against four strains of A. fumigatus. D+I, Domiphen+Itraconazole.