Comparison Of Four Anti-Avian IgY Secondary Antibodies Used In Western Blot And Dot-Blot ELISA To Detect Avian Bornavirus Antibodies In Four Different Bird Species

Escandon, Paulina; Heatley, J Jill; Berghman, Luc R; Tizard, Ian; Musser, Jeffrey MB

In serologic testing of birds, variations in the specificity of the secondary antibody used can generate erroneous results. Our study demonstrated species specificity of secondary antibodies to bird IgY in Western blot and dot-blot ELISA. Our results suggest that rapid, patient-side serologic assays for ABV antibodies in psittacines, such as the dot-blot ELISA, should employ anti-IgY secondary antibody against a similar psittacine species. In this study, the use of anti-macaw IgY secondary antibody in the dot-blot ELISA for testing antibody-positive Blue and gold macaw plasma generated appreciably better visible signals with consistently higher signal intensity than the use of antibird, anti-duck, or anti-chicken IgY secondary antibodies ( Figure 2 ; Table 1 ). Though some studies have used antichicken secondary antibody in serologic assays in wild birds, 28, 29 our results were in agreement with a study that found the use of anti-passerine IgY secondary antibody in a microplate ELISA performed better than anti-chicken and anti-bird secondary antibodies when testing passerines. 25 In fact, we found that the use of antimacaw IgY secondary antibody, in both the Western blot and the dot-blot ELISAs, showed strong species specificity for psittacines. Conversely, the use of anti-macaw IgY secondary antibody showed no difference between positive and negative Mallard plasma in either of the immunological assays (Figures 1 and 2 ; Table 1 ). Due to the diversity of avian species that can be infected with ABV, specificity of the secondary antibody to the antiglobulin species being tested is critically important and must be considered in the development of ABV assays and in ABV research.