FIGURE 4.

Anti-biofilm effect of SBT343 extract on other staphylococcal strains. (A) Photographs of wells of 96-well plate showing biofilms in the absence and presence of SBT343 extract after crystal violet staining. Control (modified ISP2 medium extract: 125 μg/ml) and SBT343 extract treated (125 μg/ml). (B) Dose dependent inhibitory effect of Streptomyces sp. SBT343 extract on biofilm formation of other staphylococcal strains on polystyrene flat-bottom 96-well plates. Staphylococcal strains treated with the extract from modified ISP2 medium (250 μg/ml) served as the appropriate control in the experiment; (C) Growth curves of staphylococcal strains in the presence of BIC₅₀ and highest tested concentration (125 μg/ml) of the SBT343 extract. Graphs represent mean values ± SEM from three independent repetitions of the experiment done in quadruplicate. ns: not significant, ^∗p < 0.05, ^∗∗p < 0.01, ^∗∗∗p < 0.001, and ^∗∗∗∗p < 0.0001.