Answer:
Streptococcus Pneuomiae
Explanation:
I think that S. Pneumonae would be the most characteristic example of a pathogen with a capsular polysaccharide virulence factor.
This is a gram-positive, catalase-negative, alpha-hemolytic and optochin-sensitive bacterium. It is responsible for a broad spectrum of disease, most importantly community-acquired pneumonia, sinusitis, otitis media and meningitis in adults.
Sign and symptoms of an S. Pneumoniae disease can vary, but it commonly includes fever, difficulty breathing, productive cough, headache and, in the case of meningitis, neck rigidity, and diminished alertness.
Interestingly, there are other Streptococcus species (i.e. Streptococcus Viridans) that share some of S. Pneumoniae characteristics and is clinically relevant (can cause heart inflammation, also known as endocarditis, in patients with prosthetic heart valves), but lacks the polysaccharide capsule, effectively making this organism a much less virulent one.
