Figure 5.

A 4ϕC³⁰ mixture is active in prevention and treatment of Pseudomonas aeruginosa biofilms. Prevention of biofilm formation and treatment of pre-existing biofilm assays were performed using P. aeruginosa clinical isolates DS22 and DS36 and DS38, the strains forming the greatest amount of biofilm as detected by MTT assay (see Fig. 1). Phage challenge doses are shown on the upper X-axis and the phage yield is shown on the lower X-axis. Biofilm prevention (left column): 24 hour biofilm formation assays were performed in the presence of serial 10-fold dilutions of the 4ϕC³⁰ mixture, washed, and biofilm determined with the MTT assay Treatment of pre-existing biofilm assays (right column): biofilms were formed for 24 hours, washed, and challenged with serial 10-fold dilutions of the 4ϕC³⁰ mixture. After 6 hours in the presence of phage, the wells were washed and biofilm determined by MTT assay. All data are the mean SEM of 3 independent determinations. Student's t-test, (P =<0.05) was used to compare the control and phage treated OD-ODc values for each phage dose.