FIG 7.

Rhamnolipids directly kill S. constellatus. (A) Viability of the planktonic fraction of S. constellatus 7155 single and mixed biofilms with the wild type or the rhlA mutant of P. aeruginosa PA14 on CF airway cells not treated with tobramycin or treated with 5 μg/ml tobramycin. (B) Viability of S. constellatus 7155 grown as single biofilms on CF airway cells treated or not treated with 50 μg/ml rhamnolipids, as indicated. *, P value < 0.05, as determined by Mann Whitney test. (C) Viability of S. constellatus grown planktonically overnight in THY medium treated or not treated with 50 μg/ml rhamnolipids, as indicated. *, P value < 0.05, as determined by an unpaired t test. (D) Viability of planktonic S. constellatus 7155 incubated in phosphate-buffered saline (PBS) with or without 50 μg/ml rhamnolipids, as indicated. *, P value < 0.05, as determined by one-way ANOVA, followed by Tukey's posttest for multiple comparisons. The bars (A to C) and data points (D) indicate the means and the error bars indicate the SD of the results from three biological replicates.