Streptococcus pneumoniae capsular polysaccharide serotype 9N (CPS 9N)

The Streptococcus pneumoniae capsular polysaccharide serotype 9N is a complex carbohydrate polymer that forms the outermost protective layer of the bacterium. It is a critical virulence factor that enables the pathogen to evade the host's innate immune response by inhibiting complement deposition and opsonophagocytosis by neutrophils. Structurally, the serotype 9N polysaccharide consists of a linear pentasaccharide repeating unit containing D-glucose, D-glucuronic acid, 2-acetamido-2-deoxy-D-glucose, and 2-acetamido-2-deoxy-D-mannose. Serotype 9N is a significant cause of invasive pneumococcal disease, including pneumonia, meningitis, and bacteremia, particularly in adult and elderly populations. It is included as a key antigenic component in the 23-valent pneumococcal polysaccharide vaccine (PPSV23) and the 21-valent pneumococcal conjugate vaccine (Capvaxive) to stimulate the production of protective, serotype-specific antibodies. These vaccines aim to reduce the incidence and severity of pneumococcal infections by priming the immune system to recognize and clear the bacteria upon exposure.

Other names

Pneumococcal polysaccharide serotype 9NS. pneumoniae serotype 9N capsuleCPS 9NPneumococcal polysaccharide type 9NStreptococcus pneumoniae serotype 9N capsular polysaccharide

Active immunization through the induction of serotype-specific IgG antibodies that facilitate opsonophagocytosis and clearance of the bacteria by the host immune system.