Figure 2.
Regulation of msrA1/msrB locus in a methicillin-resistant S. aureus strain COL. The msrA1/msrB promoter-lacZ reporter strains were cultured in TSB and growth was measured as OD600 (a). β-galactosidase activity levels were measured in wild-type S. aureus strain COL (open triangles) and its derivatives msrA1 (open circles), msrB (closed triangles), and msrA1-msrB (open square) mutants during different stages of growth (b). Values indicate averages of data from at least three independent experiments ± standard error (∗ significant at p ≤ 0.05).