Polysaccharide capsule of Neisseria meningitidis serogroup

The polysaccharide capsule of Neisseria meningitidis serogroup is a surface-expressed, high-molecular-weight carbohydrate layer that is the primary virulence determinant of the organism, enabling resistance to host immune responses, particularly complement-mediated killing[1][4]. Thirteen capsule types (serogroups) are defined by the chemical structure of their repeating units; six serogroups (A, B, C, W, X, Y) are the main causes of invasive meningococcal disease[1]. The capsule is the principal antigen for protective immunity and is the basis for licensed polysaccharide and conjugate vaccines. Its biosynthesis and export genes are clustered in the cps locus, and its structural variability underlies both disease epidemiology and challenges for vaccine design. Capsule switching through genetic recombination enables immune evasion and is an important factor in the bacterium’s persistence and vaccine breakthrough[3][4][2].

Other names

Meningococcal capsuleNeisseria meningitidis capsular polysaccharideMeningococcal polysaccharide capsuleCapsular polysaccharide of Neisseria meningitidis

Antibody-mediated opsonization and complement activation after immunization with capsule-derived vaccines, leading to bacterial clearance[5][1]