Effect of bacampicillin and ampicillin on the phagocytic, microbicidal functions of human macrophages.

During acute bacterial infections, antibiotics only assist the phagocytic system in eradicating the invading organism. In this regard, the effect of ampicillin and its prodrug bacampicillin on the phagocytosis and killing of Staphylococcus aureus by human macrophages was compared. Bacterial phagocytosis was enhanced after pre-incubation of staphylococci with bacampicillin. At a concentration of half the MIC bacampicillin showed a much more impressive killing capacity on macrophage-ingested live bacteria than did ampicillin, under all the experimental conditions tested.