Immunoblot studies in the differential diagnosis of porcine brucellosis: an immunodominant 62 kDa protein is related to the mycobacterial 65 kDa heat shock protein (HSP-65).
Smooth Brucella spp. share certain lipopolysaccharide antigens with other bacteria, resulting in serological cross-reactions which can prevent the definitive diagnosis of brucellosis. To identify other antigens with serodiagnostic potential, immunoblot studies following sodium dodecyl sulphate-polyacrylamide gel electrophoresis were carried out. Sera from pigs experimentally infected with Brucella suis and naturally infected feral pigs, sera from pigs from a farm with a known history of Yersinia enterocolitica 0:9 infection, Brucella Complement Fixation Test (CFT) reactor pigs (aetiology unknown) and pigs from consistently Brucella CFT negative farms were examined. Although B. suis infected pigs recognized a total of nine B. melitensis antigens, individual pigs rarely recognized more than three antigens in the range. A 62 kDa antigen was recognized by the majority (73%) of the Brucella infected pigs, but only by 10 to 23% of pigs from the other groups. This antigen was shown to be the Brucella homologue of the ubiquitous 65 kDa heat shock protein (HSP-65) family by immunoblot studies with 14 monoclonal antibodies to the Mycobacterium leprae HSP-65. Only four of these monoclones (Y1.2, ML-30, D7C and IIIC8) identified the B. melitensis 62 kDa protein suggesting that unshared, potentially Brucella specific, regions exist. Sera from Y. enterocolitica 0:9 infected pigs, CFT reactor pigs (aetiology unknown), CFT negative pigs and hyperimmune pig serum raised to Y. enterocolitica 0:9 also recognized B. melitensis antigens, most notably a 17 kDa protein. This antigen appears to be a common cross-reactive protein.
Spencer
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FAO/WHO Collaborating Centre for Reference and Research on Brucellosis, Central Veterinary Laboratory, Addlestone, Surrey, UK.
Broughton
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Hamid
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Young
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D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology; D000942:Antigens, Bacterial / Q000276:immunology; D002002:Brucella / Q000276:immunology*; D002006:Brucellosis / Q000175:diagnosis / Q000662:veterinary*; D003168:Complement Fixation Tests; D003429:Cross Reactions; D003937:Diagnosis, Differential; D006360:Heat-Shock Proteins / Q000276:immunology*; D007106:Immune Sera / Q000276:immunology; D015151:Immunoblotting; D016056:Immunodominant Epitopes / Q000276:immunology*; D009166:Mycobacterium leprae; D013552:Swine; D013553:Swine Diseases / Q000175:diagnosis*; D015009:Yersinia Infections / Q000276:immunology / Q000662:veterinary; D015008:Yersinia enterocolitica / Q000276:immunology
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D006360:Heat-Shock Proteins; D007106:Immune Sera; D016056:Immunodominant Epitopes