The effects and significance of subminimal inhibitory concentrations of antibiotics

Subminimal inhibitory concentrations of antibiotics cause structural alterations in gram-positive and gram-negative bacteria and, in certain instances, reduce growth of bacteria, enhance phagocytosis, increase the bactericidal activity of human serum, and induce production of beta-lactamase from gram-negative bacilli. Extrapolation of these in vitro effects to infection in humans is difficult but appears to be most appropriate in patients who receive synergistic combinations of antibiotics.