Figure 1.

Activity of compound 62520 at sub-inhibitory concentrations. (A) The WT A. baumannii ATCC 17978 and reporter strain OH101 were treated with different concentrations of compound 62520 for 24 h and bacterial growth was measured at OD₆₀₀. The relative bacterial growth was determined by the OD₆₀₀ in each concentration of compound 62520 relative to the OD₆₀₀ in the control (0 μg/mL). Data are presented as the mean ± SD of three independent experiments. (B) A. baumannii ATCC 17978 was treated with different concentrations of compound 62520 for 24 h and then total RNA was extracted. The expression levels of ompA were analyzed by qPCR. Data are presented as the mean ± SD of the expression levels of ompA in A. baumannii ATCC 17978 treated with compound 62520 relative to those of untreated control bacteria. Data were obtained from three independent experiments. (C) SDS-PAGE and western blotting of the outer membrane fractions in A. baumannii ATCC 17978. The arrow indicates the OmpA protein. The values in western blotting represent the intensity of bands relative to the intensity of untreated bacteria. (D) A. baumannii ATCC 17978 was inoculated in 96-well plates and different concentrations of compound 62520 were then added. Bacteria were treated with virstatin (100 μM) as a positive control. The biofilm mass was quantitated as the OD₅₇₀ normalized to the OD₆₀₀. Data are presented as the mean ± SD of three independent experiments. * p < 0.05, ** p < 0.01 compared with the control bacteria.