Evidence of Brucella infection in marine mammals in the North Atlantic Ocean

Between 1983 and 1996 a total of 1386 samples of serum were taken from four species of seal and three species of whale in the waters west of Iceland, the area of pack-ice north-west of lan Mayen, the northern coast of Norway and the Kola Peninsula, the waters west of Svalbard, and the Barents Sea; t hey were tested for the presence of anti-Brucella antibodies with an indire ct ELISA (protein G conjugate). The positive sera were re-tested with class ical brucellosis serological tests, such as the serum agglutination test, t he EDTA-modified serum agglutination test, the Rose Bengal test, and the co mplement fixation test, as well as an anti-complement ELISA Anti-Brucella a ntibodies were detected in all the species investigated, except for the bea rded seal (Erignathus borbatus), with the following prevalences: hooded sea ls (Cystophora cristata) 35 per cent; harp seals (Phoca groenlandica) 2 per cent; ringed seals (Phoca hispida) 10 per cent; minke whales (Bolaenoptera acutorostrata) 8 per cent; fin whales (Balaenoptera physalus) Il per cent; and sei whales (Balaenoptera borealis) 14 per cent. An isolate belonging t o the genus Brucella was obtained from the liver and spleen of one of the s eropositive minke whales. The findings suggest that antibodies against the surface lipopolysaccharide of Brucella species are widely distributed among marine mammals in the North Atlantic Ocean.