Early response in neonatal septicemia. The effect of Escherichia coli, Streptococcus agalactiae and tumor necrosis factor on the generation of lactoferrin.

Using an in vitro model, we report the early effect of Escherichia coli (E. coli), Streptococcus agalactiea (group B streptococci, GBS) and recombinant tumor necrosis factor alpha (TNF) on the release of lactoferrin (LF) and the generation of interleukin-1 (IL-1) due to E. coli, using heparinized whole blood from healthy full-term newborns. We wanted to find a dose response relationship between lactoferrin generation on the one hand and the amount of E. coli, GBS and TNF on the other hand. In a final concentration of 10(7) per ml both bacteria increased the release of LF significantly. The response to E. coli was immediate and mg/l +/- 0.29 mg/l, E. coli 1.83 mg/l +/- 0.76 mg/l, p less than 0.001). GBS was a less potent stimulant than E. coli and the response was only apparent after 20 minutes (mean +/- S.D.: 1.06 mg/l +/- 0.49 mg/l, p less than 0.01). TNF in a concentration of 10000 pg/ml as well as 1000 pg/ml increased the release of LF significantly (after 20 minutes mean +/- S.D.: 1.09 mg/l +/- 0.42 mg/l and 0.97 mg/l +/- 0.36 mg/l, respectively), whereas a concentration of 100 pg/ml had no effect. Whole blood incubated with different preparations of LF for 20 minutes did not increase the generation of LF significantly. No significant changes in IL-1 levels were observed. Lactoferrin had bacteriostatic but no bactericidal effect on GBS and Streptococcus mutans.