PRISTINAMYCIN ACCUMULATION BY STAPHYLOCOCCUS AUREUS

Abstract

Pristinamycins I_A and II_A (PI_A and PII_A) accumulation by Staphylococcus aureus has been studied with two hydrogenated analogs, (H₂)PI_A and (H₂)PII_A. Rapid accumulation of both antibiotics at 3°C is observed and internal concentrations can reach up to 58-fold the external concentration; this accumulation cannot he reduced by either metabolic inhibitors or tetracycline. The synergistic activity of pristinamycins I_A and II_A is not observed at the bacterial accumulation level. We propose that pristinamycins enter into bacteria by a passive diffusion process and that the internal concentration is maintained by binding of the antibiotic to the bacterial ribosomes.