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. 2016 Nov 7;11(11):e0165831. doi: 10.1371/journal.pone.0165831

Fig 3. Effect of GRA and GRA derivatives on S. aureus cell viability under non-growing conditions.

Fig 3

Cell viability was evaluated under non-growing conditions following the addition of GRA or GR-SU. The methods are described in the Materials and Methods section. S. aureus MW2 was treated with 1x MIC and 2x MIC of GR-SU (grey bar) or GRA (white bar) in 10 mM sodium phosphate buffer. An untreated bacterial culture (black bar) was used as a control. After 1 and 2 h of incubation, the reaction mixtures (100 μl) were plated on trypticase soy agar and incubated at 37°C overnight. The colony forming units (CFUs) were determined as the total number of colonies identified on each plate. The antibacterial effect was calculated as the ratio of the number of surviving cells (survival rate %) to the total number of bacteria incubated. Three independent experiments were performed, and the mean ± SD was calculated. The data were analyzed for statistically significant differences compared to the untreated control by a two-way ANOVA followed by Dunnett’s post hoc test. Significant differences were not observed.