Some Serological Properties of Staphylococcal Cells and Cell Walls

Discussion and Summary

The present studies indicate that Staphylococcus aureus strain 18Z contains at least seven antigenic components, and the cell walls possess at least two. Among these components, one protein antigen which has positive electric charge at pH 7.4 is mainly contained in the cell walls.

It was also shown that the virulent strain and the avirulent mutant strain contained the same antigenic components. However, the interesting question—whether or not the virulent strain may possess an antigen which is not contained in the avirulent strain— could not be settled. It is of course quite possible that an antigenic component which is responsible for virulence is not extractable by the methods described above.

Dr. Gunnar Haukenes has isolated a carbohydrate from Staphylococcus aureus which he considers to be group-specific and identical with the A carbohydrate of Wieghard and Julianelle (7). Dr. Haukenes has found this carbohydrate in the 18Z parent strain and its several mutants (Personal communication from Dr. Per Oeding).

An arguable hypothesis is that the difference in virulence between 18Z-D and 18Z-A and 18Z-C is dependent upon an extracellular cytopathogenic factor; no evidence for this hypothesis was obtained by Kapral and Li (1). Perhaps a more probable hypothesis is that strain 18Z-D possesses some subtle metabolic defect of unknown nature.