Maridomycin, a new macrolide antibiotic: in vivo antibacterial activity of 9-propionylmaridomycin.

The in vivo protecting activity of 9-propionylmaridomycin, a derivative of the new macrolide antibiotic, maridomycin, was compared with that of other macrolide antibiotics in mice infected with Staphylococcus aureus, Streptococcus pyogenes, and Diplococcus pneumoniae. The protective effect was almost similar to that afforded by several known macrolide antibiotics in mice infected intraperitoneally with certain strains of the gram-positive species described above. The skin lesion caused by intradermal challenge of S. aureus in mice also responded very effectively to treatment with 9-propionylmaridomycin.