In vitro maintenance of adult Fasciola in bile medium

Fascioliasis caused by Fasciola hepatica and Fasciola gigantica is a world wide disease in distribution with a considerable economic and public health importance. When the adult alive parasites are available in the laboratory، the physiology and biochemistry of parasite can be investigated independently of interference by host related factors، excretory- secretory products of parasite can be collected for immunological studies and evaluation of new anthemintic drugs can be performed. Several attempts have been made to keep Fasciola alive outside the body of it''s host. In this study the maintenance of parasite in the bile medium is investigated. Adult lived worms were collected from the bile ducts of slaughtered sheep and cattle and transported to the parasitology laboratory. The needed bile was collected from the gall bladders of newly slaughtered animals. After washing in normal saline، the lived worms were maintained at 30oC and 3 oC in different types of bile medium. When the collected worms from cattle were cultivated in bovine bile، the best result was obtained in 37oC، when the medium was containing diluted bile، antibiotic and Natrium azide. The mean survival time of worms was 52 hours. When the collected worms from sheep were cultivated in ovine bile، the best result was obtained in 30oC، when the medium was containing diluted bile، antibiotic and liver extract. The mean survival time of worms was 59. 25 hours. While the parasite survive in bile ducts of its hosts for long time، in vitro maintenance of the worms in bile medium is not easy. Bacterial and fungal contamination، decomposition of bile، toxic waste products of parasite، starvation of worms، unsuitable temperature، osmotic pressure، pH، pO2 and pCo2 are probable causes for short survival time of Fasciola in the bile medium.