title: A comparison between IgG antibodies against Eimeria acervulina, E. maxima, and E. tenella and oocyst shedding in broiler-breeders vaccinated with live anticoccidial vaccines.
abstract: The aim of this study was to compare the IgG response against Eimeria acervulina, E. maxima, and E. tenella and oocyst shedding in broiler-breeders vaccinated with live (virulent or attenuated) anticoccidial vaccines. Serum and faeces samples were collected from chickens before (4 days of age) and after (25 days of age) vaccination with virulent (group A) or attenuated (group B) vaccines and unvaccinated control birds (group C). Criteria for evaluation included the number of oocysts shed on the litter (McMaster technique), the levels of specific serum IgG (ELISA) and the frequencies of antigenic fractions recognised by IgG antibodies (immunoblotting). The results demonstrated that the virulent vaccine (A) presented an ideal association (low oocyst number and high IgG positive rate) for E. acervulina and E. tenella while the immunised flock with the attenuated vaccine (B) demonstrated this ideal association only for E. maxima. Both vaccinated flocks demonstrated a better association for three Eimeria spp. studied when compared to the control group, which presented a divergent association (high oocyst number and low IgG positive rate), particularly for E. acervulina. Immunoblotting assays revealed different antigenic fractions that may be considered as immunodominant antigens. The present study suggests that E. acervulina is critically present in the region studied and the use of live anticoccidial vaccines (virulent or attenuated) showed to be effective to control the clinical coccidiosis in vaccinated flocks.
mesh_terms: D000818:Animals; D002645:Chickens / Q000276:immunology*; D003048:Coccidiosis / Q000276:immunology* / Q000662:veterinary*; D004539:Eimeria / Q000276:immunology*; D016786:Eimeria tenella / Q000276:immunology*; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D015151:Immunoblotting; D007074:Immunoglobulin G / Q000276:immunology*; D007700:Kinetics; D008297:Male; D033661:Oocysts; D011201:Poultry Diseases / Q000276:immunology*; D016052:Protozoan Vaccines / Q000276:immunology*; D013045:Species Specificity; D014613:Vaccines, Attenuated / Q000276:immunology
chemical_list: D007074:Immunoglobulin G; D016052:Protozoan Vaccines; D014613:Vaccines, Attenuated