K.T. MacKnight; T.D. Williams; N.A. Vedros
University of California, Berkeley, CA; Monterey Bay Aquarium,
Monterey, CA
A serological study was conducted on sera and plasma from 117 wild and
captive sea otters. Sera from three river otters were also tested. Sea otter sera were
obtained from animals at the Monterey Bay Aquarium, animals living along the California
coastline, and animals from Alaska. River otter sera were obtained from captive animals at
Ocean Park Aquarium, Hong Kong.
An enzyme-linked immunosorbent assay (ELISA) was developed and used to
test each serum for the presence of specific antibodies against various bacterial species.
Sera were tested for antibodies directed against Vibrio alginolyticus, Vibrio
cholerae, Vibrio parahaemolyticus, Salmonella newport, Salmonella pullorum,
Salmonella typhimurium, Pasteurella multocida, and Staphylococcus aureus
(coagulase positive). The V. alginolyticus and S. aureus cultures were isolated from sea
otters. The S. newport was isolated from a California sea lion. The P.
multocida was isolated from an Atlantic grey seal. The other organisms were stock
cultures isolated from humans. These organisms were chosen due to their potential
pathogenicity for humans as well as marine mammals.
The ELISA results were analyzed using statistical methods to determine
the significant cut-off optical absorbance values for each antigen tested. Although the
results varied, they indicate that sea otters are capable of responding immunologically to
each of these eight organisms. The methodology used to prepare the ELISA tests, and the
results obtained for these otter sera will be discussed.