This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteria, Subject name: Microbiology
Species of Brucella acquired from contact with goats & sheeps - 
Select and explain. 
A. B melitensis, B. B suis, C. B abartus, D. B canis
A: B melitensis
Answer: A: B melitensis 
Explanation: Ans. is 'a' i.e., B melitensis * There are following four species of Brucellae1. Brucella melitensis# It is the commonest cause of symptomatic disease in humans.# It is the most virulent and invesive species.# It usually infect goats, sheeps and camel.2. Brucella suis# It is of intermediate virulence and primarily infects swin (pigs).3. Brucella abortus# It is of low virulence and primarily infects cattle or buffalo.4. Brucella canis# It infects dogs.