Impaired bacterial killing by FHL-5 neutrophils. Killing of S aureus and E coli was assessed in cord blood (control A; n = 6) of healthy (control B/C; n = 10) control participants and in patients with FHL-5 as described in the Study design section. Remaining viable bacteria were quantified as colony-forming units (CFU) and were expressed as % of CFU at t = 0. For the control group, the values shown are averages ± SEM, and for the patients the average of 2 measurements from 2 (patient A/B) or 3 (patient C) independent experiments are shown; *, P < .05; Grubbs outlier test (patient A/B) or Student t test (patient C). Note that the killing of S aureus is virtually normal, whereas E coli killing is significantly impaired for all 3 patients.