[Postantibiotic effects (PAE's) of macrolide antibiotics evaluated using Bioscreen C method]

Postantibiotic effects (PAE's) of macrolide antibiotics were determined for Staphylococcus aureus and Enterococcus faecalis using viable counting and Bioscreen C method and the two methods were compared. No major differences between the two methods were observed. The Bioscreen C method was less laborious than the viable counting. The durations of PAE for S. aureus following exposures to erythromycin (EM), josamycin (JM) and rokitamycin (RKM) for 2 hours at twice the MICs were in ranges of 0.85 to 1.45, 2.36 to 3.48 and 1.93 to 5.45 hours, respectively. A definite PAE of 1.0 to 5.8 hours was also observed in E. faecalis strains exposed for 2 hours to EM, JM and RKM at twice the MICs.