FIGURE 2.

Membrane vesicles (MVs) from MRSA ST541 can protect β‐lactam‐susceptible Staphylococcus aureus, preventing β‐lactam antibiotic‐induced growth inhibition in the bacteria. (a) Representative growth profiles of β‐lactam‐susceptible S. aureus cells in the presence of growth‐inhibiting concentrations of β‐lactam antibiotics. The growth‐inhibiting concentrations of antibiotics were ampicillin, 60 μg/ml. The data were presented as means and standard error of the mean (SEMs) of at least three independent experiments. (b) The survival percentages of β‐lactam‐susceptible S. aureus cells in the presence of the above‐listed growth‐inhibiting concentrations of antibiotics and MVs were calculated by bacterial counts of cultures at a certain time point (ampicillin, 12 h). CFU of S. aureus cells in medium without any antibiotics were used as a positive control and taken as 100%, to which corresponding CFU of samples were compared. The data were presented as means and SEMs of three independent experiments. *p < 0.05, **p < 0.01