Antibiotics produced by Streptomyces olivaceus 142. Antifungal properties of antibiotic WR-142 FPG.

Antifungal activity of antibiotic Wr-142 FPG was evaluated in vitro and in vivo. In vitro, the minimal inhibitory concentration (MIC) for Candida and Rhodotorula was 0.1 microgram/ml (preparation I) and 0.003 microgram/ml (preparation II). In vivo, experiments were carried out with model of subacute candidiasis in BALB mice. The criteria for antifungal activity of Wr-142 FPG were based on survival time of infected animals and numbers of live C. albicans cells in the kidneys and spleen of animals infected and treated with the antibiotics. Even a single intraperitoneal injection of Wr-142 FPG in mice with subacute candidiosis decidedly in prolonged survival time. Antibiotic Wr-142 injected subcutaneously on five consecutive days diminished the numbers of C. albicans cells, or even eliminated them entirely from the kidneys and spleens of the mice.