Antimicrobial activity of everninomicin against clinical isolates of Enterococcus spp., Staphylococcus spp., and...

The in-vitro antimicrobial activity of everninomicin, a novel oligosaccharide antibiotic, was tested against clinical isolates of 11 methicillin-susceptible Staphylococcus aureus (MSSA) strains, 11 methicillin-resistant S. aureus (MRSA) strains, 22 Staphylococcus epidermidis strains, 23 Enterococcus faecalis strains, 23 Enterococcus faecium strains, 23 Enterococcus avium strains, 27 Streptococcus pneumoniae strains, 22 Streptococcus pyogenes strains, and 20 Streptococcus agalactiae strains. The minimum inhibitory concentrations (MICs) of everninomicin were determined by Etest and compared with those of vancomycin, teicoplanin, and minocycline. The Etest showed that everninomicin exhibited excellent activity (MIC, <0.016 to 1.5 microg/ml) against the gram-positive cocci tested. The antimicrobial activity of everninomicin against S. aureus and S. epidermidis was stronger than that of vancomycin, teicoplanin, and minocycline, in particular against MRSA, with an MIC50 of 0.38 microg/ml and an MIC90 of 0.5 microg/ml. Against strains of enterococci and streptococci, everninomicin was more active than vancomycin, but as active as teicoplanin.