This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: general microbiology, Subject name: Microbiology
Following grows in the cell free medium except - 
Select and explain. 
A. Rickettsia, B. M leprae, C. Baonella, D. Syphilis
A: Rickettsia
Answer: A: Rickettsia 
Explanation: Rickettsiae cannot be grown in cell-free culture media. They usually grow in the cytoplasm of infected cells. REF:Textbook ofMicrobiologyy, Anantha Narayan, and Paniker. Page no.: 406