In vitro and in vivo antibacterial evaluation of DRF 8417, a new oxazolidinone

Objectives and methods: DRF 8417, a novel Oxazolidinone, has been evaluated against Gram-positive and fastidious Gram-negative bacteria. In vitro activity of DRF 8417 was determined by broth microdilution method and in vivo efficacy studies were carried out in different murine systemic Infection models.

Results: DRF 8417 exhibited potent activity against Gram-positive pathogens with MIC(50) and MIC(90) values ranging from 0.06 to 1 mg/L. MICs against Haemophilus influenzae and Moraxella catarrhalis were one to two dilutions lower than those of linezolid. The in vivo efficacy, by oral route, in different susceptible and resistant Gram-positive systemic Bacterial infection models ranged from 2.0 to 2.9 mg/kg.

Conclusions: These studies displayed the excellent in vitro and in vivo activity of DRF 8417 against Gram-positive pathogens and lower MICs when compared with linezolid against H. influenzae and M. catarrhalis.