Immunologic properties of soluble materials from Brucella species.

The purpose in this study was to examine the immunogenic properties of various preparations of aqueous ether extracts of Brucella suis and Brucella canis. The B suis strain 3b and B canis strain RM-6-66 were grown on tryptose agar, and aqueous ether extracts were prepared from the cells. The ether was removed, and the extracts were clarified by centrifugation for 10 hours at 144,000 X g and fractionated by gel chromatography. The B suis endotoxin-containing precipitate, obtained from aqueous ether extracted material by ethanol precipitation, and fraction 1, prepared from ultracentrifugal supernate by column chromatography, protected mice against homologous infection. The B canis aqueous ether-extracted material also protected mice against B suis infections.