Capsular polysaccharide type 5 of Staphylococcus aureus (CP5)

Capsular polysaccharide type 5 (CP5) of Staphylococcus aureus is a surface-expressed carbohydrate polymer composed of repeating trisaccharide units that form a protective capsule around the bacterial cell. This capsule is structurally unique but closely related to type 8, differing primarily in linkage and O-acetylation patterns. CP5 is encoded by the cap5 operon, a gene cluster responsible for its biosynthesis and export. CP5 is a major virulence determinant, enabling S. aureus to evade host immune responses by inhibiting opsonophagocytic killing, reducing recognition by neutrophils, and promoting persistent infection. CP5 is a leading target for vaccine development, as antibodies to this polysaccharide can promote bacterial clearance. It is a key antigen in candidate glycoconjugate vaccines aimed at preventing staphylococcal infections, including bacteremia and abscesses.

Other names

Type 5 capsular polysaccharide of Staphylococcus aureusStaphylococcus aureus CP5

For antibodies or vaccines: Induction of anti-CP5 antibodies that promote opsonization and phagocytic clearance of encapsulated S. aureus. For antisera: Specific binding to CP5 enhances immune system recognition and bacterial clearance.