FIG. 5.

Role of sarA and agr in the regulation of hla::lacZ expression and Hla activity in response to environmental conditions. S. aureus PC322 (hla::lacZ) (○, •), PC3221 (sarA hla::lacZ) (□, ■), PC324 (agr hla::lacZ) (▵, ▴), and PC3241 (sarA agr hla::lacZ) (◊, ⧫) were grown in BHI at 37°C as described in Materials and Methods. (A and B) Aerobic growth in a shaking water bath at 250 rpm; (C and D) microaerobic growth on a shaking platform in a cabinet containing 8% O₂, 5% CO₂, and 87% N₂. Bacterial growth was measured by OD₆₀₀ (○, □, ▵, ◊). (A) hla::lacZ expression was determined by measuring β-galactosidase activity (•, ■, ▴, ⧫); (B) Hla activity in cell-free supernatants (•, ■, ▴, ⧫) was determined as described in Materials and Methods.