Effect of culture media on production of excretory-secretory products and egg output of Opisthorchis viverrini in vitro.

Adult Opisthorchis viverrini were maintained metabolically active in vitro for an extended period in Earle's basal medium (BME). The worms were most active during the first 7 to 10 days of incubation and the culturing fluids were found to react in immunodiffusion with antisera. The mean survival period and egg output per worm per day could be enhanced when BME was supplemented with 5% normal, human bile but not with the same concentration of bile ultrafiltrate. A similar degree of enhancement was obtained when the medium was supplemented with 1% normal human or hamster sera. The enrichment effect of human serum could be partially replaced by albumin. However, the results obtained suggested that another serum or biliary macromolecular component(s) was required to maintain the flukes metabolically active in vitro for an extended period.