Fig 1.

Overall effects of linezolid, clindamycin, and tigecycline on PSMα₁ to PSMα₄ production. (a to c) Effects of antibiotics on the production of PSMα₁ to PSMα₄ (α1, α2, α3, and α4, respectively). All measured PSM values (μg/ml) were normalized to OD₆₀₀ and then calculated as percentages relative to the baseline. Isolates (n = 10) included only those that produced measureable PSMα peptides at the baseline (***, P < 0.0001; **, P < 0.001; *, P < 0.05). (d) Strain-to-strain variability of PSMα₁ production at 1/8 MIC of tigecycline (TYG). Strains were grouped according to their baseline PSMα₁ production as very low (<1 μg/ml), low (1 to 5 μg/ml), medium (6 to 15 μg/ml), and high (>15 μg/ml) producers.