Dot ELISA as a rapid method for serological diagnosis of canine brucellosis

In this work, we describe a dot-enzyme linked immunosorbent assay with two different antigens of Brucella canis. The antigens, soluble sonic and outer membrane proteins were adsorbed on to a solid nitrocellulose surface. The test was applied to 40 field serum samples previously analysed by the rapid slide agglutination test and the 2-mercaptoethanol tube agglutination test. Sera were obtained from clinically suspected dogs of different age, sex and breed. Sera were also obtained from four clinically healthy animals and used as a negative control. One sample originated from a female with a high antibody titer and positive isolation of Brucella canis. Out of the 44 examined sera, 19 had agglutination titers > 1/50. A positive reaction to proteins of the soluble sonic extract, was obtained with 10 sera and with outer membrane proteins with 7 sera. All positive sera in the dot-ELISA had agglutination titers > 1/100. This study shows that proteins of soluble sonic extract of Brucella canis in dot-ELISA are reliable and highly specific for rapid diagnosis of brucellosis in dogs.