Comparative in-vitro activity of LY146032 a new peptolide, with vancomycin and eight other agents against gram-positive organisms.
The in-vitro activity of LY146032, a new biosynthetic peptolide antibiotic, was compared with vancomycin and eight other antibiotics against 190 Gram-positive bacteria. Organisms tested included streptomycin-susceptible and resistant enterococci, nafcillin-susceptible and resistant Staphylococcus aureus, and nafcillin-susceptible and resistant Staph. epidermidis. LY146032 had excellent in-vitro inhibitory and bactericidal activity against nafcillin-susceptible and resistant staphylococci (MIC90 less than or equal to 0.5 mg/l) and against enterococci (MIC90 less than or equal to 2.0 mg/l). LY146032 was more active than vancomycin against the majority of isolated tested. With the exception of trimethoprim-sulphamethoxazole, LY146032 was the most active agent in vitro against enterococci, and was the most active against nafcillin-resistant staphylococci. LY146032 and vancomycin showed a marked increase in MIC when the inoculum was increased from 10(5) to 10(7) cfu/ml. LY146032 and vancomycin were bactericidal at concentrations within two dilutions of the MIC for staphylococci. LY146032 was bactericidal at less than or equal to 8 mg/l for all enterococcal isolates tested.
Benson
C A
CA
Department of Medicine, Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois 60612.
Beaudette
F
F
Trenholm
G
G
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D017576:Daptomycin; D006094:Gram-Positive Bacteria / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D009254:Nafcillin / Q000494:pharmacology; D010403:Penicillin Resistance; D010455:Peptides / Q000494:pharmacology; D014640:Vancomycin / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D010455:Peptides; D009254:Nafcillin; D014640:Vancomycin; D017576:Daptomycin