Enhancement of goldfish virus-2 in vitro replication by the pesticides carbaryl and toxaphene.

Goldfish virus-2 replication was enhanced in vitro by pretreatment of CAR cells with subcytotoxic concentrations of carbaryl and toxaphene. This phenomenon was time and temperature dependent. Shortening of pretreatment with carbaryl eliminated enhancement, which was observed for toxaphene only with substantially increased concentrations. Decreasing the temperature of pretreatment (4 degrees C) abrogated any enhancement by carbaryl and resulted in enhancement by toxaphene only at increased concentrations. Increased absorption of input virus was ruled out as a mechanism for enhancement, as was stimulation of cell division in the presence of pesticides over that of control cultures. Pretreatment of virus rather than cells did not result in enhancement.