Molecular pathogenesis of the hyaluronic acid capsule of Pasteurella multocida.

Pasteurella multocida possesses a viscous capsule polysaccharide on the cell surface, which is a critical structural component and virulence factor. Capsular polysaccharides are structurally similar to vertebrate glycosaminoglycans, providing an immunological mechanism for bacterial molecular mimicry, resistance to phagocytosis, and immune evasion during the infection process. Based on the capsular antigen, P. multocida is divided into A, B, D, E, and F five serogroups. Previously, we systematically reported the biosynthesis and regulation mechanisms of the P. multocida capsule. In this paper, we take serogroup A capsular polysaccharide as the representative, systematically illuminating the P. multocida capsular virulence and epidemiology, molecular camouflage, adhesion and colonization, anti-phagocytosis, anti-complement system, cell invasion and signal transduction mechanism, to provide a theoretical basis for the research of molecular pathogenic mechanism of P. multocida capsule and the development of polysaccharides vaccine. • P. multocida possesses a viscous capsule polysaccharide, which is a critical structural component and virulence factor. • Capsular polysaccharides are structurally similar to vertebrate glycosaminoglycans. • The type A P. multocida , the most common serogroup, produces a HA capsule, playing a dominant role in virulence. • The HA capsule of P. multocida is recognized by and adheres to the host cell-surface CD44 protein or its isoforms. [ABSTRACT FROM AUTHOR]