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
All the following statements about Listeria are true, EXCEPT: 
Select and explain. 
A. It is a gram negative bacteria, B. It causes aboion in pregnancy, C. It causes meningitis in neonates, D. It is transmitted by contaminated milk
A: It is a gram negative bacteria
Answer: A: It is a gram negative bacteria 
Explanation: Listeria monocytogenes is a sho coccoid, gram positive, catalase positive non spore forming rod with a tendency to occur in chains. They show tumbling motility at 20 - 25 degree centigrade and is non motile at 37 degree. The major virulence factors are invasion associated surface proteins called internalin and a pore-forming cytotoxin, listeriolysin O (LLO). Ref: Sherris Medical Microbiology By Kenneth J. Ryan, 5th Edition, Chapter 26 ; Textbook of Microbiology By Ananthanarayan and Panicker, 8th Edition, Page 395