Brucellosis is an infectious disease caused by bacteria. People can get the disease when they are in contact with infected animals or animal products contaminated with the bacteria. Animals that are most commonly infected include sheep, cattle, .Brucellosis is a highly contagious zoonosis caused by ingestion of unpasteurized milk or undercooked meat from infected animals, or close contact with their secretions. It is also known as undulant fever, Malta fever, and Mediterranean fever. Brucella species are small, Gram negative, nonmotile, nonspore forming, rod shaped coccobacilli bacteria. They function as facultative intracellular parasites, causing chronic disease, which usuall.Brucellosis is an infectious disease caused by a type of bacteria called Brucella. The bacteria can spread from animals to humans. There are several different strains of Brucella .