[Subinhibitory concentrations of antibiotics. Effects on morphology and growth (author's transl)].

Experiments with subinhibitory concentrations of antibiotics revealed certain effects that had not been observed at higher concentrations. Two different effects are described: morphological changer and inhibition of growth. The expression minimum antibiotic concentration (MAC) has been shown to be of both theoretical and practical value. It has served to make plain the differences between the effects of various antibodies that were not observed at the MIC. The ratio MAC/MIC could be be of importance to characterize the effect of antibiotics.