Erythrocytes suppress neutrophils in whole blood, but do not completely suppress bacterial killing. (A) Neutrophil killing of MRSA or E coli K12 was evaluated with increasing concentrations of erythrocytes at 30 and 90 minutes. Neutrophil killing of MRSA (top). Positive control is neutrophils plus MRSA. Statistics were analyzed by repeated measures one-way ANOVA and post hoc Holm–Sidak's multiple comparison test; n = 3. **P < .0057; ***P < .0001 versus control values considered statistically significant. Neutrophil killing of E coli (bottom). Positive control is neutrophils plus E coli. Statistics were analyzed by repeated measures 1-way ANOVA and post hoc Holm–Sidak's multiple comparison test; n = 3. **P < .05 versus control values considered statistically significant; ***P < .0003. (B) Neutrophils were incubated with MRSA for 90 minutes, and degranulation was measured by elastase release on fluorescent plate reader at ex. 488/emm.530; n = 3. Statistics were analyzed by ordinary 1-way ANOVA. ***P < .0001 versus control values considered statistically significant. N:E, neutrophil:erythrocyte.