Inhibition by G-CSF of in vitro phagocytosis and killing of Klebsiella by neutrophils. K pneumoniae B5055 was grown for 6 hours in the absence or presence of G-CSF (10 ng/mL) and subsequently subjected to phagocytosis of PMN in the presence of 60% normal human serum as described in Materials and Methods. Data are from four independent experiments, each performed in duplicate, and are given as median ± quartiles. *, P = .014 compared with the corresponding time point of controls grown in the absence of G-CSF (Mann-Whitney U test).