Group B Streptococcus capsular polysaccharide serotype V (GBS CPS V)

Group B Streptococcus capsular polysaccharide serotype V (GBS CPS V) is a complex carbohydrate structure located on the outermost surface of Streptococcus agalactiae, a major human pathogen [1, 4]. It serves as a critical virulence factor by facilitating immune evasion; specifically, its terminal sialic acid residues mimic host cell surfaces, thereby inhibiting the alternative complement pathway and preventing opsonophagocytosis [1, 5]. Serotype V is one of the most prevalent serotypes associated with invasive GBS disease, including neonatal sepsis, meningitis, and infections in pregnant women and the elderly [2, 17]. As a therapeutic target, GBS CPS V is primarily utilized in the development of conjugate vaccines, where the polysaccharide is linked to a carrier protein to enhance immunogenicity [16, 21]. These vaccines aim to elicit high titers of serotype-specific opsonophagocytic antibodies, which provide protection through maternal-fetal transfer or direct immunization of at-risk adults [6, 28].

Other names

Type V GBS capsular polysaccharideGBS serotype V CPSStreptococcus agalactiae serotype V capsuleGBS CPS V

Induction of opsonophagocytic antibodies (IgG) that facilitate complement-mediated killing and phagocytosis of the bacteria [6, 16].