In-vitro evaluation of miokamycin: bactericidal activity against streptococci.

Miokamycin is a diacetyl derivative of the macrolide antibiotic, midecamycin. In vitro, it has an unusual spectrum, inhibiting the growth of Gram-positive cocci and anaerobes, but few Haemophilus spp; enterobacteria are highly resistant. Most erythromycin-resistant Staphylococcus aureus were sensitive (MIC approximately 0.8 mg/l). Resistance to miokamycin in Staph. aureus and streptococci was difficult to select, unless the staphylococci were already resistant to erythromycin. Both miokamycin and erythromycin were bactericidal towards groups A,B,C and G streptococci. Clinical trials of the drug in pelvic, upper respiratory, skin and soft tissue and other staphylococcal infections may be worthwhile.