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
The mode of infection of Pasteurella multocida? 
Select and explain. 
A. Endogenous infection, B. Animal bites or scratches, C. Human beings, D. Aerosols and dust
B: Animal bites or scratches
Answer: B: Animal bites or scratches 
Explanation: Ans (b) Animal bites or scratches Pasteurella multocida Group of bacteria similar to Yersinia often carried in the upper respiratory tract of variety of animals such as dogs, cats, cattle. It may cause hemorrhagic septicemia in these animals. P. multocida is nonmotile, Gram-negative bacilus, resembling Yersinia, but differing in being oxidase-positive, producing indole and failing to grow on MacConkey agar. Human infection is rare but may occur following animal bites or scratches. Clinical manifestation includes local suppuration, meningitis (following bite in head) respiratory tract infection. Tetracycline and streptomycin are drug of choice.