Studies on the immunochemistry of Staphylococcus aureus cell wall: antigenicity of pentaglycine bridges.

The specific antigenicity of pentaglycine bridges in cell walls of S. aureus was investigated. The antistaphylococcal sera (against 11 Oeding strains of S. aureus) were found to contain antibodies of two different specificities against polyglycyl peptides; one type reacted with polyglycyl peptides with a free amino terminus and the other with polyglycyl peptides with a free carboxyl terminus. These antibodies were assayed by passive hemagglutination with tanned sheep red cells sensitized with N-polyglycyl-BSA (containing polyglycyl peptides with a free amino terminus) or with C-poe antibodies against N-polyglycyl peptides were absorbed by S. aureus strains and by S. epidermidis. Heterologous bacterial species failed to absorb antibodies of either specificity. Antibodies against polyglycyl peptides were used to confirm the mechanism of action of penicillin on S. aureus cell wall.