Staphylococcus aureus interaction with Pseudomonas aeruginosa biofilm enhances tobramycin resistance

Staphylococcus aureus filtrates (SaF) do not affect initial attachment of Pseudomonas aeruginosa to borosilicate slide chambers. a Schematic representation of how SaF biofilm formation was assessed. P. aeruginosa was grown overnight in liquid culture prior to seeding in 8-well slide chambers. After 6？h of attachment, media was removed and replaced with fresh media. b Representative images of P. aeruginosa biofilms grown for 24？h in the presence of 10% (v/v) SaF in LB. Green cells: live; red cells: dead. c–f Image analysis of biofilm thickness c, surface coverage d, biomass e and % dead cells f for given biofilms. Biofilms were grown as described above in the presence of LB alone (black bars) or 10%SaF (white bars) prior to image acquisition and analysis with COMSTAT. N？=？7 eradicated isolates and N？=？7 persistent isolates. The mean of PA01 was generated from seven biological replicates. All means are plotted with standard deviation. Statistics were performed using non-parametric one-way ANOVA (Kruskal–Wallis) with Dunn’s post-test for multiple comparison