Oritavancin

171099-57-3

C86H97Cl3N10O26

1793.1

White or off-white powder

Source: Semi-synthetic

-20 °C

Spectrum: Effective against Gram-positive bacteria. It is effective at killing biofilm-producing pathogens like methicillin-resistant S. aureus (MRSA) and vancomycin-resistant enterococci (VRE).

Microbiology Applications: Oritavancin is commonly used in clinical in vitro microbiological antimicrobial susceptibility tests (panels, discs, and MIC strips) against Gram -positive isolates. Medical microbiologists use AST results to recommend antibiotic treatment options. Representative MIC values include: S. aureus: 0.12 µ/ml - 4 µg/ml MRSA: 0.25 µg/mL – 4 µg/mL Researchers studied the effect of polysorbate 80 on oritavancin binding to plastic surfaces and found it was rapidly lost from solution in susceptibility assay test plates. Greater losses were observed at lower concentrations suggesting saturable binding to surfaces. The inclusion of 0.002% Polysorbate 80 permitted the recovery of 80-100 % oritavancin, and it is suggested to use it in broth microdilution. It putatively blocks the nonspecific binding sites on he surfaces of the test vessels. The 16- to 32-fold reductions in the oritavancin MICs for the staphylococci and enterococci in the presence of polysorbate 80 are likely a result of polysorbate 80 inhibition of the binding of oritavancin to plastic surfaces. Investigators should use caution during in vitro and in vivo experiments to ensure proper assessment of the intended concentration. (Arhin et al, 2008).