Dose-response cell viability assay.

For the 12-h experiments, 0.01 to 100 μg/ml of PyS2-GN4 was incubated statically at 37°C with P. aeruginosa strain 453 at 10⁶ CFU/ml in CAA medium with 0.5 mg/ml EDDHA. At 2-h increments, an aliquot was removed from each sample and plated on CAA agar to determine viable bacterial counts. For the 24-h experiments, lysocin at 0.1 to 100 μg/ml was incubated statically at 37°C with P. aeruginosa strain 453 at 10⁶ CFU/ml in either CAA medium or CAA-HuS (1:1) with EDDHA. After 24 h, the samples were plated on CAA agar to assess bacterial viability. An untreated control was used for each data set. All samples were investigated in duplicate.