Screening for new antitrichomonal substances of microbial origin and antitrichomonal activity of trichostatin A.

In vitro and in vivo screening methods for new antitrichomonal substances were established. Primary screening is based on in vitro antitrichomonal activities of culture broths of actinomycetes isolated from soil. With secondary screening, after crude materials obtained from the cultured broths were administered orally to mice, excretion of antitrichomonal activity into urine was examined. Tertiary screening was done by examining therapeutic activity for experimental trichomoniasis in mice with Trichomonas foetus. Using the screening systems, a new antibiotic (setamycin)-producing strain was picked out among about six thousands soil isolates, and the therapeutic efficacy of KM-3851, which was identified as trichostatin A, was found. It was active against T. foetus both in vitro and in vivo.