Bacteriolytic activity in staphylococci.

The bacteriolytic activity of Staphylococcus aureus and Staphylococcus albus strains was tested with various media. Whereas S. aureus strains were found to be active under all conditions, the percentage of active S. albus strains was significantly influenced by the composition of the medium. Ionic strength and concentration of the organic nitrogen source were found to be the main factors affecting the expression of bacteriolytic activity of straphylococci. Virtually all of 318 S. aureus and 603 S. albus strains were active on a medium containing 3% peptone, 0.3% glucose, 0.2% yeast extract, 0.1% disodium phosphate, 2.2% sodium chloride and 0.9% agar. The optimal conditions for the bacteriolytic activity of S. aureus strains were different from those of most S. albus strains. Within S. albus, optimal conditions differed also from strain to strain. It is suggested that further studies on this subject may prove useful for the identification and taxonomy of staphylococci. A possible relationship between the production of extracellular bacteriolytic enzymes and pathogenic properties of staphylococci is also considered.