Brucella are gram-negative bacteria that are pathogenic for humans and a varietyof livestock animals and wildlife. The genus Brucella has six recognized species onthe basis of host specificity : B.abortus , B.melitensis, B.suis, B.canis, B.ovis,B.neotomae. The six species have been subdivided into 19 biovar based on culture andbiochemical characteristics. The greatest economic impact result from bovinebrucellosis caused by B.abortus. Infection decreases reproductive efficiency mainly byabortion. B.abortus c...