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
Medusa head colonies on nutrient agar is seen in? 
Select and explain. 
A. Pneumococcus, B. Legionella, C. Brucella, D. Anthrax
D: Anthrax
Answer: D: Anthrax 
Explanation: Ans. is 'd' i.e., Anthrax BACILLUS ANTHRACIS Morphology ? Gram positive Non motile (all other members of genus Bacillus are motile) Arranged singly, in pairs or in sho chains Capsulated - entire chain being surrounded by a capsule. - Capsule is polypeptide Sporing - Spores are formed in culture or in soil but never in animal body during life. Chain of bacilli presents a bamboo stick appearance.