Josamycin and Rosamicin: In Vitro Comparisons with Erythromycin and Clindamycin

Abstract

The macrolide antibiotics josamycin and rosamicin were compared in vitro with erythromycin for activity against Staphylococcus aureus, S. epidermidis , and enterococci and with clindamycin for activity against a variety of anaerobic organisms. Rosamicin and erythromycin were similar in activity and superior to josamycin against aerobic cocci. Most isolates of S. aureus (96%), S. epidermidis (79%), and the enterococci (87%) were inhibited by 1.56 μg of either of the new macrolide compounds per ml. Clindamycin was the most active compound against the anaerobic organisms.