<prompt> The polysaccharide capsule of following bacteria has in role in their infectivity exceptHaemophilus influenzaNeisseria meningitidesStreptococcus pneumoniaeBordetella peussis  <response>: 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. 