Immunogenicity Analysis of Staphylococcus aureus Clumping Factor A Genetic Variants

The staphylococcal adhesin clumping factor A (ClfA) has a variant amino acid sequence, generating the potential for alterations in epitope structure and immunogenicity of this vaccine candidate. We demonstrated for two recombinant ClfA(40-531) (a slightly truncated version of the fibrinogen-binding domain of ClfA containing amino acids 40 to 531) genetic variants that strain-specific epitopes are immunodominant. This work indicates that immune responses elicited by ClfA may, at least in part, be dependent on the strain of origin of the ClfA.