Fig. 1
Virulence factors release by inducible MLSB-resistant S. aureus strains after sub-MIC of clindamycin treatment. Hla (a), PVL (b) and TSST-1 (c) release were measured by ELISA detection after clindamycin treatment (1/2 MIC, 1/4 MIC and 1/8 MIC) in comparison to the growth control without clindamycin. The averages represent two determinations for each condition. For each strain, virulence factor release at 1/2 MIC, 1/4 MIC and 1/8 MIC of clindamycin were pooled (n = 6) to perform the t test to compare with growth control without antibiotic (= 100%) and calculate the 95% confidence interval of the average. *p < 0.05; **p < 0.01; ***p < 0.001. Lack of a chart bar means that the factor virulence release measure was below the detection limit (i.e., 0.75 ng/mL for Hla and 1.56 ng/mL for TSST-1)