Fig. 4

In vitro effect of antibiotic in soluble and formulated forms on S. aureus under planktonic and biofilm modes of growth. a Planktonic S. aureus relative growth after 24 h of co-culture with RIF, NP-RIF or NP-RIF-PLL at different concentrations. b Relative adhered biomass of S. aureus biofilms stained by CV, after 24 h of co-culture with different concentrations of RIF, NP-RIF or NP-RIF-PLL on 24 h-old biofilms, followed by washing. c Relative viability of the bacteria from S. aureus biofilms evaluated by MTT, after 24 h of co-culture with different concentrations of RIF, NP-RIF or NP-RIF-PLL on 24 h-old biofilms. Percentages are reported to the untreated condition. Values are means ± SD of three replicates for one representative experiment out of three independent ones. Paired t-tests (compared to the untreated condition), *** p < 0.001. ANOVA (between formulations), ns: not significant