F. Hemmen et al., CLONING AND SEQUENCE-ANALYSIS OF A NEWLY IDENTIFIED BRUCELLA-ABORTUS GENE AND SEROLOGICAL EVALUATION OF THE 17-KILODALTON ANTIGEN THAT IT ENCODES, Clinical and diagnostic laboratory immunology, 2(3), 1995, pp. 263-267
A thus far unknown gene encoding a Brucella abortus protein has been i
solated from a lambda gt11 expression library probed with sera from Br
ucella-infected sheep, Sequence analysis of the cloned gene revealed t
he presence of an open reading frame of 158 amino acids encoding a pro
tein of 17.3 kDa (calculated molecular mass). The recombinant B. abort
us protein, expressed in Escherichia coli, and the corresponding Bruce
lla melitensis protein migrated at the same apparent molecular masses
as shown by Western blotting (immunoblotting). Among a series of serum
samples from B. melitensis- or B. abortus-infected sheep and cows, 51
and 39%, respectively, showed a signal at 17 kDa on Western blot anal
ysis of total protein extract from Brucella bacteria, These figures am
ount to 70 and 61% for sheep and cattle, respectively, in a competitiv
e enzyme-linked immunosorbent assay with a specific monoclonal antibod
y, These data indicate that the 17-kDa antigen may be useful for serol
ogical diagnosis of Brucella infection.