Plate and Tube Agglutination Tests for Diagnosis of <i>Brucella abortus</i> Biotype 1 Infection in Sprague-Dawley Rats

The plate and tube agglutination tests were evaluated for the diagnosis of experimentally induced Brucella abortus biotype 1 infection in 45 female, 6 to 10 months old Sprague- Dawley (SD) rats during the period from 2001 to 2002. These 45 rats were divided into two groups A and B, of which group A consisting of 27 rats used for experimental infection, whereas 18 rats of group B served as uninfected control. Each rat of group A was injected subcutaneously @ 1.0×109 colony forming units (CFU) in 500 µl of bovine pathogenic strain of B. abortus biotype 1 suspension in physiological saline. The SD rats were monitored at regular intervals by serological and bacteriological methods. The reciprocal antibody titer was 1:400 through tube agglutination test (TAT) whereas it was 1:800 through plate agglutination (PAT) at first week of post-infection. There was no reciprocal antibody titer in sera of 24 weeks of post-infection both through PAT and TAT despite the presence of bacteremia and these tests were evaluated for the first time using sera from rat with brucellosis. PAT using B. abortus strain 1119-3 (S1119-3) whole cell antigen was a potential candidate as an improved diagnostic method for field diagnosis of brucellosis in wild animals. Key words: B. abortus biotype 1; plate and tube agglutination tests; Sprague-Dawley rats doi: 10.3329/bjvm.v2i1.1938 Bangl. J. Vet. Med. (2004). 2 (1) : 63-67