USING OF BRUCELLA CELL ENVELOP AS AN ANTIGEN IN DIAGNOSIS OF OVINE BRUCELLOSIS

In this study serum samples from 35 Brucella culture positive and 80 Brucella culture negative sheep were used to evaluate the use Whole Cell Sonicate (WCS) and Cell Envelop (CE) antigens prepared from Brueclla melitensis type 3 (field strain) for ELISA. These samples were also tested using Rose Bengal test (RBT), Buffered acidified plate test (BAPT), Rivanol test (Riv. T.) and Tube agglutination test (TAT). The results showed that 35 (100%) of the examined sera from the culture positive group were positive in BAPA, RBT and TAT tests while 34 (97.14%) were positive for Riv. T. However, from 80 ani- mal from the culture negative group, 7 (8.75%), 8 (10%), 5 (6.25%), and 8 (10%) were positive for RBT, BAPA, Riv. T and TAT respectively. The serum samples of these animals were then tested by indirect ELISA using WCS and CE antigens. From the 35 culture positive animals 35 (100%) showed positive results, while, from the 80 culture negative animals 5 (6.25%) and 2 (2.5%) were positive in WCS and CE ELISA respectively. The sensitivity of ELISA with both WCS and CE antigens was 100%. It is clear that WCS and CE detect all culture positive sheep. The specificity of ELISA for WSC was 93.75% and for CE was 97.5%. In conclusion CE seems to be effective for diagnosis of Brucella melitensis infection in sheep by ELISA.