Infect Chemother.  2003 Oct;35(5):271-276.

In vitro Antimicrobial Activity of Linezolid (Zyvox(R)) against Multidrug Resistant Gram-Positive Organism

• Park DW
• Cheong HJ
• Eom JS
• Hwang BY
• Kim SB
• Lee JG
• Lee YJ
• Jeong H
• Jung SJ
• Park JH
• Lee JS
• Sohn JW
• Kim WJ
• Kim MJ
• Park SC

Abstract

BACKGROUND: The emergence of multi-drug resistant Gram-positive cocci, such as MRSA, VRE, and VRSA, necessitated to develop new antibiotics, which could replace the glycopeptide. As a result, a new antibiotics named linezolid was developed. Linezolid is different line of oxazolidinones with a good oral bioavailability, compared to other antibiotics. Since appropriate oral antibiotics are not presently available for MRSA, which is a major cause of nosocomial and community acquired infections, the introduction of linezolid will have favorable effect on treatment of infections such as pneumonia or skin infections. In this study, we investigated the antibiotic effect of linezolid on MRSA and VRE isolated from patients who were treated in Korea University Guro Hospital. MATERIAL AND METHODS: By using broth microdilution and agar dilution method we measured minimum inhibitory concentration (MIC) with sixty S. aureus, forty three Enterococcus spp., and twenty five S. pneumoniae isolates from patients who were diagnosed as skin, soft tissue, respiratory, and urinary infections in Korea University Guro Hospital from January, 1998 to December, 2002.
RESULTS
All of S. aureus used in this study were MRSA, and MIC90 of linezolid was below 2 microgram/ml (MIC ranged between 1-2 microgram/ml). All of Enterococcus spp. were VRE, and had MIC90 of 2 microgram/ml (MIC ranged between 1 to 4 microgram/ml). One of the VRE showed intermediate susceptibility with MIC of 4 microgram/ml. However, none was resistant with MIC breakpoint above 8 microgram/ml. All of S. pneumoniae were resistant to penicillin, but they were susceptible to linezolid with MIC90 of 1 microgram/ml(MIC range 0.5-1 microgram/ml).
CONCLUSION
In conclusions, linezolid has an excellent in vitro antibiotic effect on multi-drug resistant Gram-positive cocci, such as MRSA, PRSP, and VRE.

Keyword

Linezolid; MRSA; VRE; PRSP; MIC

MeSH Terms

Agar
Anti-Bacterial Agents
Biological Availability
Community-Acquired Infections
Enterococcus
Gram-Positive Cocci
Humans
Korea
Linezolid
Methicillin-Resistant Staphylococcus aureus
Microbial Sensitivity Tests
Oxazolidinones
Penicillins
Pneumonia
Skin
Agar
Anti-Bacterial Agents
Oxazolidinones
Penicillins