A Simple Process for the Experimental Induction of Resistance in Schistosoma mansoni to Antihistosomal Agents.

Abstract

This study was carried out to identify the easiest process of inducing drug resistance in the parent generation of S.mansoni in mice after subjecting them to drug pressure. Adult albino mice were infected with S.mansoni cercariae and were given various subcurative doses of nidazole orally at 2 weeks, 4 weeks and 8 weeks(that is 14,28 and 56 days) post-ceecarial infection followed by curative doze of nitridazole for (250 mgkg body weight for 5days). We found that the adult worms (8 weeks old)were highly susceptible to nitridazole treatment and did not survive the various subcurative treatment that was given. But when three consecutive courses of (100mgkg/1b.wt for 5 days) of nitridazole was given to mice 14 and 28 days post cercarial infection,resistance (Tolerance) occurred with the recovery of 34.82 and 28.28% worms, respectively when curative treatment was given to mice. mice with two weeks old infections were preferred and thus served as appropriate model for the induction of resistance to nitridazole,while other antihistomal agents may be tested using this method. The process was reproducible and has been valuable for experiments to study the biological characteristics of the drug resistant S.mansoni.