title: Factors contributing to the resistance of chickens to infection with Japanese Fasciola sp.
abstract: Attempts were made to clarify the factors contributing to the resistance of chickens to infection with Japanese Fasciola sp. Infection was not successfully established in chickens by oral inoculation of metacercariae, nor by inoculation of excysted juvenile flukes into the body cavity or to the liver surface. Many metacercarial cysts were detected within two days in the feces of orally inoculated chickens. In the in vitro excystation test with chicken bile at 42 degrees C, metacercariae emerged successfully. These results indicate that the major resistant factors may not act during the migration from the mouth to the liver. Histopathological examination of the liver of experimental chickens could not prove the effect of a resistant factor. Excysted flukes were cultivated at 37-42 degrees C in RPMI1640 supplemented with calf serum, with the result that the survival rate of flukes fell with higher temperatures. When chicken serum was used instead of calf serum, flukes survived for a long period of time at 37 degrees C, while all died within four days at 42 degrees C. The higher body temperature of chickens than that of other mammalian hosts is considered to be the major factor contributing to the resistance of chickens to infection with Fasciola sp.
authors.affiliation: Department of Animal Hygiene, Faculty of Agriculture, Kobe University, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Kawano
authors.forename: M
authors.initials: M
authors.lastname: Koga
authors.forename: A
authors.initials: A
authors.lastname: Shimizu
authors.forename: S
authors.initials: S
authors.lastname: Kimura
mesh_terms: D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood; D001646:Bile / Q000276:immunology; D002645:Chickens / Q000469:parasitology*; D005209:Fasciola / Q000276:immunology / Q000302:isolation & purification / Q000502:physiology; D005211:Fascioliasis / Q000276:immunology / Q000662:veterinary*; D005243:Feces / Q000469:parasitology; D005260:Female; D007113:Immunity, Innate; D008099:Liver / Q000469:parasitology / Q000473:pathology; D011201:Poultry Diseases / Q000276:immunology*
chemical_list: D000909:Antibodies, Helminth