Fig. 8
Gene expression analysis. Graphs of gene expression analysis for three genes coding for the lipoteichoic acid assembly cascade. a Bacterial growth after 4 h exposure to different concentrations of pseudonajide (peptide 2). Culture medium with 2% DMSO was used as a control, and rifampicin was the antibiofilm positive control. OD600 was measured at time zero and at 24 h for growth normalization. For gene expression analysis, cDNA was obtained through reverse transcriptase reactions on mRNA extracted from Staphylococcus epidermidis cultured in the presence (peptide) or absence (control) of 6.25 μM pseudonajide. b Expression levels of genes ugtP, ltaA, and ltaS under the same testing conditions. c Expression levels of biofilm-related genes under these same conditions. The 2-ΔΔct method was used to normalize expression levels to 16S rRNA [34]. All tests were performed in at least 3 different biological replicates each having at least 3 technical replicates. Error bars are shown, and statistical analysis was performed using Student’s t-test, where: *, p < 0.05