IN-VITRO ANTIFUNGAL ACTIVITY OF CAN-296 - A NATURALLY-OCCURRING COMPLEX CARBOHYDRATE

The in vitro activity of a naturally occurring complex carbohydrate, C AN-296, was evaluated by testing 132 clinical and ATCC isolates of yea st and Aspergillus fumigatus, many of which were azole-resistant. The in vitro susceptibility tests were performed by standardized broth mic ro- and macrodilution methods and results were compared with those obt ained for amphotericin B, fluconazole, ketoconazole, flucytosine and t he pneumocandin L-733,560. All tested Candida species showed highly un iform susceptibility to CAN-296 at concentrations of 0.078 to 0.312 mu g/ml; non-albicans Candida were as susceptible to CAN-296 as the Cand ida albicans strains. Multi-azole-resistant Candida species were highl y sensitive to CAN-296. Minimum inhibitory concentration measurements did not differ from minimum lethal concentrations by more than two-fol d for all tested Candida species. Aspergillus fumigatus, on the other hand, showed only moderate susceptibility to CAN-296. The kinetics of the anti-Candida activity of CAN-296 was investigated by kill-curve ex periments using C. albicans and C. glabrata and the results were compa red with those obtain for amphotericin B. CAN-296 was found to be rapi dly fungicidal in concentrations ranging from 4 similar to 16 fold the mean MIC value. The broad spectrum of anti-Candida activity together with the rapid fungicidal effect make this complex carbohydrate a prom ising agent for clinical use.