Spontaneous occurrence of Staphylococcus aureus mutants with different pigmentation and ability to produce toxic shock syndrome toxin 1.

Spontaneous mutants that have pigmentation different than that of their parents were isolated from three Staphylococcus aureus strains associated with toxic shock syndrome. These mutants produced toxic shock syndrome toxin 1 in amounts varying from less than 0.05 to greater than 25 times that produced by the parents. The occurrence of nonpigmented variants may be overlooked if only one isolate from a patient with toxic shock syndrome is selected for analysis.