Figure A2.

Invasion rate of MRSA strains from different genetic backgrounds. After 2 hr of infection at an MOI of 100:1, external and adherent bacteria were removed by lysostaphin treatment for 1 hr. The MG‐63 cells infected with the different strains were osmotically lysed, and the number of intracellular bacteria was determined by plating serial dilutions of the lysates on blood agar plates and counting the colonies grown after overnight incubation at 37°C. The graph reports the mean ± SD for each clone for two different experiments