This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
A veterinary doctor had pyrexia of unknown origin. His blood culture in special laboratory media was positive for gram-negative short bacilli which was oxidase positive. Which one of the following is the likely organism grown in culture ? 
Select and explain. 
A. Pasteurella spp, B. Francisella spp, C. Bartonella spp, D. Brucella spp
D: Brucella spp
Answer: D: Brucella spp 
Explanation: Points in favor of Brucellosis:

Veterinary doctor: Occupational exposure to infected animals
Organism could grow only in special laboratory media
Oxidase positive Gram-negative short bacilli
Brucellosis is one of the common cause of PUO