Fig. 7.

Effect of iron starvation on T3SS-dependent hemolytic activity of B. bronchiseptica RB50. Dilutions of normalized bacterial suspensions prepared from iron-replete (open circles) and iron-depleted (filled circles) SS cultures were incubated with rabbit RBC, and liberated hemoglobin was measured by absorbance at a wavelength of 490 nm. Mean absorbance values (n = 3, ±1 SD) are shown. Dashed lines show control absorbance values corresponding to hemoglobin released in the absence of bacteria (no bacterial cells) and by hypotonic lysis of rabbit RBC using water (100% RBC lysis).