In vitro Activity of A-16686, a New Glycopeptide

Abstract

A-16686 is a novel glycopeptide antibiotic derived from Actinoplanes. A-16686 inhibited hemolytic streptococci groups A, B, C, F, and G at concentrations of ≤ 0.06 to 0.5 μ g/ml, with 90% inhibited by 0.5μ g/ml, including erythromycin-resistant isolates. S. bovis, various viridans groups streptococci, S. mitis, S. mutans, and S. sanguis were inhibited by ≤ 1 μ g/ml, and MICs of S.faecalis and S.faecium were 0.5–2 μ g/ml. Most staphylococci, including methicillin-resistant strains, were inhibited by 1 or 2 μ g/ml. A-16686 was bactericidal with minimal difference between MIC and MBC for gram-positive species. A-16686 did not inhibit Enterobacteriaceae or Pseudomonas.