Time-kill study of the in vitro antimicrobial activity of tedizolid against methicillin-resistant Staphylococcus aureus

Abstract

Objective: To evaluate the in vitro antimicrobial activity of tedizolid against clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) by time-kill curve experiments. Materials and Methods: Four bacterial strains were used in methicillin susceptibility tests including MRSA strain H0340, H5086, H6023, and H7515, obtained from Department of Microbiology at King Chulalongkorn Memorial Hospital. The minimum inhibitory concentrations (MICs) were determined by macrodilution method. Results: The time-kill curves were conducted using H5086 strain, showing the highest MIC of 0.25 μg/ml. The time-kill studies also showed that tedizolid exhibited bacteriostatic activity at all concentrations (from 0.25× to 16× MIC) with a reduction in growth of <3 log10 colony forming units (CFU)/ml. Furthermore, the compound appeared to have a maximum effect at the concentration of 8× MIC with 1.8 log10 CFU/ml reduction from the initial inoculum at 12 h. Conclusion: Tedizolid is potentially a good antimicrobial activity for MRSA with bacteriostatic activity.