ABSTRACT
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 animal 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