Phenol-Water Fractions from Smooth Brucella abortus and Brucella melitensis: Immunochemical Analysis and Biologic Behavior

Aqueous and phenolic extracts and insoluble residues from smooth biotype 1 strains of Brucella abortus and Brucella melitensis were studied for immunologic and biologic comparison. Brucella differ from enterobacteriaceae in a high glucose content and lack of 3-deoxy-D-mannooctulosonic acid (KDO) in aqueous phases, in a rhamnolipid in insoluble residues, and in the high content of nitrogen in extracts made with acetic acid. Some chemical similarities may exist between Pseudomonas and Brucella. Extracts of Brucella, especially phenol extracts of B. melitensis, induce in adult mice a curable wasting disease. None of these fractions sensitize guinea pigs (as determined by dermal hypersensitivity test), but most brucella fractions are allergens for animals already infected with B. abortus. Most of the differences in biologic behavior and in antibody induction between B. abortus and B. melitensis could be associated with an unidentical distribution of similar compounds among the various fractions. In addition, B. abortus differs from B. melitensis in the lack of both galactosamine and methionine.