Fig. 5
Comparative phenotypic characteristics of an isogenic VAN-S/VAN-I pair (with missense mutation H364R). The error bars indicate the standard deviation (±SD) of values obtained by spectrophotometer in three independent tests. A P value ≤0.05 was considered as a significant difference between VAN-S and VAN-I. (A) The kinetic data set of autolysis of the S. aureus culture (in 20 ml BHIB) that washed (two times) and adjusted to an OD600 of 1 (in 10 ml cold distilled water supplemented with 0.1% Triton X-100) was measured at OD600 in the tested time points. There was a statistically significant difference (P < 0. 01) in the autolysis kinetic activity of VAN-I versus VAN-S (paired-sample Student’s t-test) at each tested point. (B) The percent of hemolysis of 300 μl of human red blood cells (RBCs) diluted in 10 ml PBS in exposure to S. aureus culture (adjusted to an OD600 of 0.3 in BHIB) was measured at OD543 using the following formula: (A543 of the sample ˗ A543 of negative control) / (A543 of positive control ˗ A543 of negative control) × 100. Negative control: diluted RBC in PBS without bacteria; Positive control: Triton X-100; the symbol (***) indicates a significant difference (P < 0.001) using the two-tailed Wilcoxon signed-rank test