TABLE 1.

Regrowth of stationary-phase S. pyogenes

Regrowth medium	CFU ml−1a	SD
Todd-Hewitt (1.0× concn)b	4.4 × 105	±1.2 × 105
Todd-Hewitt (0.5× concn)b	4.3 × 105	±1.9 × 105
Todd-Hewitt (2.0× concn)b	1.6 × 105	±2.1 × 104
Todd-Hewitt yeast extractb	1.9 × 105	±6.0 × 104
Todd-Hewitt with sheep's bloodb	3.0 × 105	±1.2 × 105
Todd-Hewitt-0.25 M sucroseb	1.7 × 105	±2.1 × 104
Todd-Hewitt-0.50 M sucrosec	2.9 × 105	±8.4 × 104
Todd-Hewitt-0.50 M sorbitold	2.4 × 105	±7.0 × 104
Todd-Hewitt-500 U catalaseb,e	3.0 × 105	±5.5 × 104
Todd-Hewitt-1,000 U catalaseb,e	2.3 × 105	±1.0 × 104
Todd-Hewitt-40 mg pyruvateb,f	5.3 × 105	±1.4 × 105
Todd-Hewitt-80 mg pyruvateb,f	4.2 × 105	±1.3 × 105

^aThe number of CFU mL⁻¹ was determined by serial dilution and subsequent platings of S. pyogenes M49-CS101 cultures aged 2 weeks in stationary phase as described in Materials and Methods.

^bSerial diluent was TH broth.

^cSerial diluent was 0.50 M sucrose solution.

^dSerial diluent was 0.50 M sorbitol solution.

^eA freshly made catalase solution was spread onto TH agar before plating.

^fA freshly made pyruvate solution was spread onto TH agar before plating.