You are not currently logged in.
Access your personal account or get JSTOR access through your library or other institution:
If You Use a Screen ReaderThis content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
An ELISA for Detecting Anti-Plasmodium spp. Antibodies in African Black-Footed Penguins (Spheniscus demersus)
Thaddeus K. Graczyk, Michael R. Cranfield, Mary L. Skjoldager and Melvin L. Shaw
The Journal of Parasitology
Vol. 80, No. 1 (Feb., 1994), pp. 60-66
Stable URL: http://www.jstor.org/stable/3283346
Page Count: 7
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Preview not available
An enzyme-linked immunosorbent assay (ELISA) utilizing 3 Plasmodium falciparum antigens, R32tet32, P.F.R27, and crude red blood cell extract, was developed for the detection of circulating anti-Plasmodium relictum or anti-Plasmodium elongatum antibodies in sera from naturally infected adult African black-footed penguins (Spheniscus demersus) at The Baltimore Zoo, Maryland. A concentration of 2.0 μ g/ml of each antigen was optimal in terms of specificity, sensitivity, and test speed. It was possible to detect anti-Plasmodium spp. antibodies at a dilution of 10-4.11. Low absorbance values (less than 0.050) of nonspecific background were observed. The binding efficacy of anti-penguin IgG coupled to alkaline phosphatase to antibodies in the penguin sera was significantly higher than the binding efficacy of anti-chicken IgG. All penguins, bled in the winter time, in controlled mosquito-free conditions had anti-Plasmodium spp. antibodies reactive with P. falciparum antigens. The penguins showed age-dependent variation in antibody levels. There was a decrease in antibody titration units that was significantly correlated with the number of outdoor exposure years experienced by the birds, despite the season-comparable epizootiologic conditions in their summer open-air habitat. We concluded that the decrease of anti-malarial antibodies could be explained by an antibody-mediated equilibrium of immunity in naturally immunized birds harboring endothelial-stage parasites. The ELISA described is sensitive, and it requires a minimal amount of equipment to collect the blood samples. The assay can be used for detecting and monitoring levels of anti-Plasmodium spp. antibodies in selected groups of penguins.
The Journal of Parasitology © 1994 The American Society of Parasitologists