Abstract
The in vitro screening tests against the in vitro cultivated $L_3$ of Ascaris suum (in vitro $L_3$), which were cultivated from the embryonated egg to third-stage larva on 7 days in culture(DIC) and the in vivo rat's lung-derived $L_3$ of Ascaris suum (in vivo $L_3$), which were recovered from the lungs of rat on 7 days after infection, carried out in order to compare the anthelmintic efficacy of in vitro $L_3$ and that of in vivo $L_3$ in RPMI medium 1640 with 5% bovine calf serum. And also a screening test of efficacy against adult worms of Trichuris suis performed. The efficacies of screening tests were as follows : 1. The screening efficacies of abamectin and ivermectin against the in vitro $L_3$ were all 100% at the 10ppm concentration in RPMI medium 1640 on 5 DIC. 2. The screening efficacies of abamectin and ivermectin against the in vivo $L_3$ were all 100% at the 20ppm on 5 DIC or at 40ppm on 3 DIC. 3. The screening efficacies of abamectin and ivermectin against the adult worms of Trichuris suis were all 100% at 20ppm on 4 DIC. And therefore, the in vitro cultivated $L_3$ of Ascaris suum were used in the screening test as well as the in vivo rat's lung-derived $L_3$ of Ascaris suum. And also the adult worms such as Trichuris suis and filaroids which is small size and difficult to cultivate to vitro, were used in the screening test in vitro.