Fever of unknown origin in a farmer who raises goats would most likely be caused by which of the following organisms?

Brucella are small, aerobic, Gram-negative coccobacilli. Of the four well-characterized species of Brucella, only one-B. melitensis-characteristically infects both goats and humans. Brucellosis may be associated with gastrointestinal and neurologic symptoms, lymphadenopathy, splenomegaly, hepatitis, and osteomyelitis.