FIG. 2.

Lysostaphin did not disrupt biofilms formed by lysostaphin-resistant S. aureus variants. Tissue culture wells (three for each sample) of a microtiter plate were inoculated with ∼10⁸ CFU of S. aureus strain SA113, SA5 LysoR, MBT 5040, or MBT 5040 LysoR (as indicated). After we allowed 48 h for biofilm formation, the wells were washed twice and then incubated with (+) or without (−) 50 μg of lysostaphin/ml in PBS for 3 h. Following incubation, the wells were washed again and stained with safranin to visualize biofilms.