Eukaryotic cellular metabolic assay
To evaluate the metabolic status of MG-63 cells following infection withS. aureus for 3h and 24h, we used the MTT ([3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide]) assay (Pedotti et al ., 2017; Fresta et al ., 2018). The formazan crystals obtained at the end of the procedure were dissolved by dimethyl sulfoxide and the Multiplate reader Synergyâ„¢ H1 (BioTek) was used to determine the colorimetric differences, detected as absorbance at 569 nm, between samples. The values obtained for infected cells were expressed as the percent variation with respect to the cellular metabolic status detected in the control, not infected, cells (which represents 100%).