ABSTRACT
The possibility of safe immunization of chicks at an appropriate age with a double-dose irradiated Ascaridia galli vaccine given orally at two weeks interval was explored. Chicks immunized at 7 or 10 days of age were not affected adversely since they did not develop any clinical signs and there was no worm establishment after challenge infection. Immunization also elicited detectable circulating antibody titres, with IHA and the conglutinating complement absorption test having a tendency to be enhanced after the booster dose.
Subject(s)
Ascaridia/immunology , Chickens/immunology , Immunization , Age Factors , Animals , Ascaridiasis/prevention & control , Chickens/parasitology , Immunization/methods , Ovum/immunology , Ovum/radiation effects , Poultry Diseases/immunology , Poultry Diseases/prevention & control , Vaccines, Attenuated/administration & dosage , Vaccines, Attenuated/immunologyABSTRACT
Growth and cell-mediated immune (CMI) responses were studied in 7-day-old chicks given orally 1000 irradiated (12.5 kR) or normal infective eggs of Ascaridia galli. Chicks immunised with irradiated eggs showed normal weight gains. CMI responses, as assessed by dinitrofluorobenzene (DNFB)-induced contact and delayed hypersensitivity reactions, were enhanced in the immunised group as compared with healthy controls, suggesting stimulation of CMI responses due to irradiation of A. galli eggs. CMI as well as growth responses were, however, found to be depressed in the birds administered normal infective eggs of A. galli. The present study highlights the role of the CMI response in protection against A. galli infection.
Subject(s)
Ascaridia/immunology , Ascaridiasis/veterinary , Chickens/parasitology , Nematode Infections/veterinary , Poultry Diseases/immunology , Animals , Ascaridia/radiation effects , Ascaridiasis/immunology , Ascaridiasis/prevention & control , Body Weight , Chickens/growth & development , Chickens/immunology , Hypersensitivity, Delayed , Immunity, Cellular , Immunization/veterinary , Ovum/immunology , Ovum/radiation effects , Poultry Diseases/prevention & controlABSTRACT
The susceptibility of various mammals to infection with Fasciolopsis buski has been studied. Mice, rats, monkeys and dogs were completely refractory. Guinea-pigs were only partially susceptible. However, young rabbits (6 to 8 weeks old) were found to be susceptible and can be used as an animal model for experimental work on this parasite.
