Fig. 2

Antibiofilm and biofilm eradication activity. (A) Antibiofilm formation (left graphs) and bacterial growth (right graphs) after 24 h of exposure to different concentrations of peptide 1, pseudonajide (peptide 2), or peptide 3. S. epidermidis ATCC 35984 cell suspension was incubated alone or in the presence of decreasing concentrations of peptides. An adapted crystal violet protocol was used for biomass measurement at optical density of 570 nm (OD₅₇₀) [29], and growth analysis was done at an optical density of 600 nm (OD₆₀₀). Culture medium with 2% dimethyl sulfoxide (DMSO), and culture medium alone were used as growth control, while rifampicin was the antibiofilm positive control. OD₆₀₀ was measured at time zero and at 24 h for growth normalization. (B) The biofilm eradication activity of pseudonajide (peptide 2), pseudonajide (bottom graph) was measured by adding 25 μM of pseudonajide in pre-formed biofilm and incubating for further 24 h. All the tests were performed with at least 3 different biological replicates each including at least 3 technical replicates. Error bars are shown, and statistical analysis was performed using Student’s t-test, where: *, p < 0.05; **, p < 0.01; ***, p < 0.001