[Spontaneous mutants of S. aureus 209 P resistant to 3,6-diaminoacridines]

Spontaneous mutants of S. aureus 209 P resistant to proflavine sulphate and possessing cross resistance to acriflavine and acridine yellow were isolated. Sensitivity of these mutants to acridine orange, acridines No. 40 and 56 remained unchanged. The phage type and the indices of potential pathogenicity of proflavine-resistant mutants coincided with the corresponding S. aureus 209 P indices.