Fig. 5

Interaction of NPs and PLL-coated NPs with planktonic S. aureus. CLSM micrographs of NP-Dy650 and NP-Dy650-PLL (in red) with initial solid contents of 0.01% (a) and 0.02% (b) interacting with Syto9-stained bacteria (in green) for 45 min, followed by washing. c Ratio of fluorescence intensities from bacteria-surrounding NP-Dy650 and NP-Dy650-PLL related to Syto9-stained bacteria. d High resolution micrograph by AiryScan detector on CLSM from b of NP-Dy650-PLL (in red) interacting with Syto9-stained S. aureus (in green). Relative bacterial growth of planktonic S. aureus exposed for 45 min to RIF, NP-RIF or NP-RIF-PLL with initial solid contents of 0.01% (e) and 0.02% (f), followed by washing to remove poorly-interacting particles and 24 h of incubation. Equivalent RIF concentrations (4 and 8 µg/mL respectively) were used under soluble form. Percentages are reported to the untreated condition. Each picture represents data obtained with three replicates in three independent experiments. Values are means ± SD of three replicates for one representative experiment out of three independent ones. ANOVA, ns: not significant, ** p < 0.01 and *** p < 0.001