Abstract

Erysipelas is considered one of the most problematic of diseases seen at facilities that house cetaceans. Cetacean erysipelas is usually manifested in one of two forms: a dermatological form, which appears as diamond- or square-shaped lesions mainly seen on the anterior dorsal area of the skin, or an acute septicemic form. In order to provide a diagnostic tool for routinely monitoring antibody titers against Erysipelothrix rhusiopathiae a biotin-avidin amplified enzyme linked immunosorbent assay (ELISA) was developed. This assay employs a "double indirect" indicator antibody system that includes biotin labeled rabbit anti-Tursiops truncatus immunoglobuhn antiserum (produced against ammonium sulfate precipitated immunoglobulins) followed by avidin-labeled alkaline phosphatase. In initial determinations of anti-Erysipelothrix antibody levels with serum samples from Delphinapterus leucas and Lagenorhyncus obliquidens, biotin labeled rabbit anti-T. Truncatus immunoglobuhn anti which cross-reacts with immunoglobulins from those species, was employed. The degree of cross-reactivity of the antisera was a variable in the assay that could not be appropriately defined, so species specific antisera were produced and biotin labeled. In order to determine if the use of species specific antisera would result in greater assay sensitivity it was necessary to test serum samples from D. leucas (provided by Naval Research and Development, San Diego, CA and the John G Shedd Aquarium, Chicago, II,) and L. obliquidens (provided by the John G. Shedd Aquarium) under both the initial assay conditions and with the appropriate species specific antisera. The results of this study indicated a relative increase in recorded titers and the number of animals showing titers against E. rhusiopathiae when the species specific antisera was utilized compared with the titers determined when anti-T. Truncatus was utilized.

Acknowledgements

This work was supported by a grant from the John G Shedd Aquarium. The authors wish to thank Dr. J. Boehm (John G. Shedd Aquarium) and Dr. S. Ridgway, Dr. B. Van Bonn, and Dr. E. Jensen (NRAD) for their generous donation of samples for this study.