Phenelfamycin E is an antibiotic originally isolated from Streptomyces. It is active against beta-hemolytic Streptoccus, S. pneumoniae, C. difficile, C. perfringens, and P. magnus128 ug/ml). Phenelfamycin E (4-64 mg/kg) increases survival in a mouse model of lethal S. pyogenes infection in a dose-dependent manner. Dietary administration of phenelfamycin E increases body weight in chickens.