Use of western immunoblot analysis for testing moose serum for Brucella suis biovar 4 specific antibodies

To determine if 12 moose (Alces alces) from northern Alaska with agglutinat ing antibodies specific for Brucella spp. had been exposed to either B. sui s biovar 4 or B. abortus biovar 1, western immunoblot serologic analysis wa s performed. Differential serologic responses to strain specific A and M an tigenic variances of the lipopolysaccharide O-polysaccharide sugar allowed strain identification. Prior to examination, test sera were absorbed with k illed whole cells from either B. abortus biovar 1, containing predominately A antigen (A(+) M-); B. melitensis biovar 1, containing essentially M anti gen (A(-) M+); or B. suis biovar 4, containing both antigenic types (A(+) M +). The resulting sera were then examined by western immunoblot for recogni tion of either B. abortus biovar 1, B. melitensis biovar 1, or B. suis biov ar 4 cell lysates. The results of this study indicate that these moose were exposed to B. suis biovar 4, a known pathogen of caribou (Rangifer tarandu s) from arctic Alaska.