Antimicrobial activity of HydH5, lysostaphin, and its derivative fusion proteins in commercial whole ELS milk.

<p>Milk was inoculated with 10⁴ CFU/ml of <i>S. aureus</i> Sa9 and incubated for 0, 15, 30 min, 1, 2, 4 and 6 h at 37°C either without lytic protein (control; dark grey bars) or in the presence of : A) 1 µM CHAP-SH3b (light grey bars), and 3.5 µM HydH5 (stippled bars), 3.5 µM HydH5SH3b (black bars) and 3.5 µM HydH5Lyso (diagonal stripes bars); 1 µM lysostaphin (gross line on X axis); (B) 1.65 µM CHAPSH3b (light grey bars), control without protein (dark grey bars), at room temperature. Values expressed as log₁₀ CFU/ml are the means ± standard deviations of two independent experiments. Bars having an asterisk are significantly different from the control (*<i>P</i>≤0.05). <i>S. aureus</i> detection threshold (<10 CFU/ml).