Fig. 3

Fingolimod-induced increase in S. aureus cell membrane permeability and disruption of cell integrity. The cell membrane permeability of the MSSA SA113 (A), and MRSA CHS350 (B) were stained for 30 min by SYTOX green (1 μM) and treated with 0.9% NaCL (negative control), 1% Triton X-100 (positive control), 2 × MIC and 4 × MIC of Fingolimod for 30 min. Then, BioTek multifunctional microplate reader was used to monitor for 20 min under the conditions of excitation wavelength of 490 nm and emission wavelength of 520 nm. S. aureus SA113 cells in the log phase of growth were treated with DMSO (C) and 4 × MIC Fingolimod (D) for 30 min. Cells were collected, washed three times with PBS (pH = 7.4), and fixed with 2.5% paraformaldehyde/PBS solution. The cell disruption were observed by transmission electron microscopy. Compared with the vehicle control group, ***, P < 0.0001 (t-test). The data presented was the average of three independent experiments (mean ± SD)