FIG 2.

S. aureus glucosaminidase mutants resistant to lysostaphin. Lysostaphin (40 μg/ml) or buffer alone was added to stationary-phase cultures of S. aureus strains suspended in 50 mM Tris-HCl (pH 7.5). Turbidity at A₆₀₀ was monitored over 3 h. Relative turbidity was calculated as the A₆₀₀ of lysostaphin-inoculated staphylococci compared to that of staphylococci in buffer alone at each time point. Lysostaphin susceptibilities of the glucosaminidase single (A), double (B), and triple and quadruple (C) mutants and of the sagB-complemented strains (D) were compared to wild-type (WT) levels.