Drug Tolerance by Tritrichomonas foetus

Abstract

A strain of Tritrichomonas foetus that remained refractory to dimetridazole, despite four courses of successively higher levels of medication (strain 4711, McLoughlin, 1965), was recovered from a bull and established intravaginally in hamsters. Tolerance for the chemical remained undiminished after maintenance of the strain in hamsters for 27 months. Also in hamsters, T. foetus that had no prior exposure to dimetridazole became unresponsive to the drug following pretreatment with suboptimal levels. The strain recovered from the bull and those from the hamsters had a detectable crossresistance to metronida-zole and to aminitrozole.