FIG. 3.

Time course of M49⁺ streptococci killed by PMNs in blood pretreated with C5a. Approximately 1,000 CFU of strain CS101 or MJY1-3 was added to 1 ml of heparinized human whole blood and rotated at 37°C. Diluted samples of blood were plated on agar plates at the indicated time points to determine the number of CFU. The growth ratio (y axis) equals the number of CFU at a given time point divided by the initial CFU at time zero. Data are the mean growth ratios from three independent experiments. The error bars depict the standard errors of the means.