Table 1.

The isolates used in this study.

Strain	M-type	CovRS status	Disease association
H305	M1	CovS mutanta	Scarlet fever
H330	M3	CovS mutantb	Puerperal sepsis and toxic shock
H529	M12	WTc	Toxic shock
H293	M89	WTc	Necrotizing fasciitis

^aStop at residue 318.

^bPro to Ser at residue 285.

^cHigh SpeB producers.