Figure 1.

Phenotypic analysis of the clinical P. aeruginosa isolates. (a) Biofilm forming proficiency of isolates from different sources (see Supplemental Table S1 for details of all clinical isolates). (b) Representative results of biofilm forming assays. The values of OD₅₇₀ are presented as means ± standard deviations (SDs) of triplicate assays. The break line indicates OD₅₇₀ value equal to 1/2 of that of PAO1. The isolates had the OD₅₇₀ values ≤ 1/2 of that in PAO1 are defined as the biofilm-deficient. (c) Analysis of proteolytic activity using the milk plate assays. Measurement of the radius of the proteolytic zones after incubation at 37  °C for 48 h. Data are the radius values from clinical isolates (gray bar) reported as the mean ± SDs from three individual experiments with triplicates in each experiment. The proteolytic zones produced by strains, PAO1 (red bar) and the isogenic mutants deficient in elastase and/or four proteases (Supplemental Table S2) (black bar) were used as the controls.