This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Microbiology
The polysaccharide capsule of following bacteria has in role in their infectivity except 
Select and explain. 
A. Haemophilus influenza, B. Neisseria meningitides, C. Streptococcus pneumoniae, D. Bordetella peussis
D: Bordetella peussis
Answer: D: Bordetella peussis 
Explanation: The polysaccharide capsule of Bordetella peusis has no significant role in its infectivity. Bordetella fresh cultures demonstrated capsules but its virulence is mainly toxin-mediated.