Streptococcus agalactiae capsular polysaccharide (GBS CPS) (GBS CPS)

Streptococcus agalactiae capsular polysaccharide (CPS) is a critical virulence factor located on the surface of Group B Streptococcus (GBS). It is composed of repeating units of oligosaccharides and is classified into ten distinct serotypes (Ia, Ib, II–IX) based on its chemical structure and antigenicity [1, 2]. The primary biological function of the CPS is to protect the bacterium from the host's immune system by inhibiting opsonophagocytosis and preventing the deposition of complement proteins like C3b on the bacterial surface [2, 3]. In humans, GBS is a leading cause of invasive neonatal diseases, such as sepsis, meningitis, and pneumonia, and it also poses a significant threat to pregnant women and elderly individuals [3, 4]. Because of its high surface exposure and critical role in pathogenesis, the CPS is the primary target for the development of glycoconjugate vaccines [4, 5]. These vaccines work by inducing serotype-specific antibodies that facilitate the recognition and destruction of the bacteria by host phagocytes [5]. Current clinical candidates, such as hexavalent conjugate vaccines, aim to provide broad protection against the most prevalent disease-causing serotypes globally [4].

Other names

Group B Streptococcus capsular polysaccharideGBS CPSS. agalactiae polysaccharideGroup B carbohydrateGBS capsular polysaccharide

Active immunization via the induction of serotype-specific opsonophagocytic IgG antibodies that facilitate bacterial clearance.