[The effect of cydectin on the survival of second stage larvae and mature Ascaris suum cultured in vitro].

Larvae of Ascaris suum (L2) newly hatched from eggs with sodium hypochlorite, were placed (2000 larvae per 2 ml) of culture in EAGLE's medium, containing 10% calve serum or without it. Moxidectin (Cydectin) was introduced into medium in concentrations: 5, 10, 25 and 50 micrograms/ml. The cultures were incubated for 3 days, and there were controlled every 12 hours. The effect of drug on survival of larvae was slightly expressed. After 3 days survival rates were 87, 81, 80 and 78% in medium with serum, respectively to moxidectin concentrations. The lethality of larvae was higher in medium without serum, and amounted to 17, 23, 29 and 31% in comparison with control probe after 72 hours. Adult Ascaris were placed on ARS medium with glucose (0.1%) containing moxidectin in concentrations 1, 5, 50 and 100 micrograms/ml. The worms' condition was examined every day based on motility and turgor of their body. After 14 days of incubation in control probe 50% worms were alive, but their vitality was reduced. The behaviour of Ascaris in the presence of 50 micrograms/ml moxidectin was similar to those from the control. Only the highest concentration of drug (100 micrograms/ml) was lethal in 100% on the 8th day. The lower moxidectin concentrations (1 and 5 micrograms/ml) were not lethal to adult worms, they had even the positive effect on survival rate and condition of adult Ascaris. The eggs laid by females which were maintained in culture with drug were collected. There were no disturbances in their future development.