Figure 1
Hemolytic activity of S. marcescens. (A) Hemolytic activity of S. marcescens strain niid 298 on several blood agars. Cells (1 × 106) were cultured overnight, and then inoculated on various blood agars and incubated at 30°C or 37°C for 16 h. Clear zones indicated hemolysis. (B) Contact hemolysis assay for human RBC. Cells harvested in log phase were mixed with washed human RBC and incubated at 30°C or 37°C for 1 h with shaking. Released hemoglobin was measured spectrophotometrically as absorbance at 405 nm. Results are shown as percent lysis compared to complete lysis of RBC in distilled water. (C) Hemolytic activity of the shlBA deletion mutant on human blood agar. Experiments were performed as in (A).