1987 Volume 40 Issue 7 Pages 946-952
Chloropolysporins A, B and C, as well as derivatives prepared from this group and α-and β-avoparcins by enzymatic and mild acid hydrolysis, were active against Gram-positive bacteria including clinically isolated methicillin-resistant Staphylococci (MIC 0.39 - 6.25 /Jg/ml) and anaerobic enterobacteria (MIC 0.10-1.56 μg/ml). Derhamnosyl and demannosyl derivatives from both groups of antibiotics showed stronger activities than the parent compounds. The MIC and MBC values against Staphylococci were similar and were not effected by the presence of serum. Moreover, chloropolysporin C exhibited very strong synergistic effects with various β-lactam antibiotics against methicillin-resistant strains of Staphylococcus aureus. Some of these compounds also protected mice from experimental infection with S. aureus. Acute toxicities of chloropolysporins by intravenous administration ranged from 215-290mg/kg in mice. Chloropolysporin B as well as other glycopeptide antibiotics, showed distinctive growth promoting activity in broiler chickens.
