Use of indirect enzyme-linked immunosorbent assay with hot saline solution extracts of a variant (M-) strain of Brucella canis for diagnosis of brucellosis in dogs.

An ELISA, using hot saline solution extracts (HSS) of a less-mucoid variant (M-) strain of Brucella canis as antigen, was developed for detection of antibodies against B canis in dogs. The test was applied to 177 field serum samples previously tested by use of the 2-mercaptoethanol rapid slide agglutination test, 2-mercaptoethanol-tube agglutination test, and agar gel immunodiffusion containing HSS and cytoplasmic antigens of B. canis. Results indicated that this ELISA seems to be highly specific (95.6%) and slightly less sensitive (93.8%). The HSS obtained from B canis wild-type RM 6/66 also have been used, but in our study, it seemed to be unsuitable for use in ELISA because of the high background values observed for sera with negative test results.