FIG. 1.

Implication of HtrA₁ and HtrA₂ proteins in growth of S. aureus RN6390 and COL virulent strains under high-temperature and puromycin stress conditions. Cultures of RN6390 or COL WT, htrA₁ (A₁), htrA₂ (A₂), and htrA₁ htrA₂ (A₁A₂) strains were grown in BHI medium at 37°C. At an OD₆₀₀ of ∼0.3, the cultures were diluted 10-fold from nondiluted (ND) to 10⁻⁴, and 10 μl of each dilution was spotted onto BHI plates without selection or with 8 μg of puromycin/ml. The plates were incubated at 37 or 44°C. Similar results were obtained for three independent experiments.