FIG 3.
Cell-free Psl kills S. aureus by disrupting the cell envelope. (A) S. aureus USA300 was incubated with spent medium from P. aeruginosa PAO1, ΔPpsl, or pagP::Tn for 2 h. Changes in cell morphology were visualized by TEM. Arrows indicate cells with disrupted cell envelopes. (B) Total and disrupted cell counts for each group were enumerated, and the percentage of disrupted cells within each group was calculated. Data are means and SD; individual points indicate biological replicates (N = 4; n = 3). Significance was determined using a one-way ANOVA compared to PAO1. *, P < 0.05.