Value of antigen and antibody detection, and blood evaluation parameters in diagnosis of avian invasive aspergillosis.
The applicability of ELISA detection of circulating Aspergillus spp. antigen (Ag) and systemic antibody (Ab) of IgG class, and the blood parameter values were evaluated for diagnosis of invasive aspergillosis in Aspergillus spp.-challenged Peking ducks (Anas platyrhynchos). The protective role of Aspergillus spp. IgG was evaluated in Cape shelducks (Tadorna cana) immunized with Aspergillus spp. Ag. Challenged but non-immunized A. platyrhynchos developed invasive aspergillosis on day 21 as demonstrated histopathologically by the presence of fungal micro-granuloma in air sacs and lung tissue, with serum antigenemia fluctuating from 65 to 270 ng of 55-kD basic protein Ag per ml. Immunized A. platyrhynchos did not demonstrate Aspergillus spp. serum antigenemia but did show rare histopathological changes in some air sacs associated with fungal inflammation. Although the differences between immunized and non-immunized T. cana in blood evaluation parameters did not differ significantly, immunized birds mounted high Aspergillus spp.-specific IgG titer. There was no correlation between the blood parameter values and post-immunization timepoints in T. cana and in A. Platyrhynchos. Intramuscular immunization with Aspergillus spp. mycelial phase cultures Ag provided protection against the pathogens. The lack of relations between blood parameter values and increasing Aspergillus spp. IgG titers (in T. cana and A. platyrhynchos) indicate low applicability of these parameters in evaluation of a bird Aspergillus spp. status. Detection of circulating 55-kDa Aspergillus spp. Ag has high early predictive values for invasive aspergillosis in birds.
Department of Molecular Microbiology and Immunology, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, Maryland 21205, USA. tgraczyk@jhsph.edu
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Graczyk
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Cranfield
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Klein
D000818:Animals; D000908:Antibodies, Fungal / Q000097:blood*; D000946:Antigens, Fungal / Q000097:blood* / Q000276:immunology; D001228:Aspergillosis / Q000175:diagnosis / Q000517:prevention & control / Q000662:veterinary*; D001230:Aspergillus / Q000276:immunology / Q000302:isolation & purification; D001715:Bird Diseases / Q000175:diagnosis*; D004372:Ducks; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D007114:Immunization; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D011237:Predictive Value of Tests
D000908:Antibodies, Fungal; D000946:Antigens, Fungal; D007074:Immunoglobulin G