Methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci: emerging problems and new prospects for management.
BACKGROUND
Infections due to multidrug-resistant Gram-positive bacteria are a growing worldwide problem, particularly among seriously ill patients. A number of studies have demonstrated that patients infected with either methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant enterococci (VRE) are at higher risk for mortality and medical resource expenditures.


METHODS
A non-systematic evidence-based review of linezolid, the first commercially available oxazolidinone, and quinupristin/dalfopristin, the first injectable streptogramin, for management of these multidrug-resistant infections was conducted.


RESULTS
As infections due to VRE increase and vancomycin-insensitive MRSA emerge, vancomycin is becoming less effective for managing Gram-positive infections. Preclinical comparative studies demonstrated that linezolid and quinupristin/dalfopristin are highly effective in eradicating both susceptible and resistant staphylococci, streptococci, and enterococci. Clinical experience, including phase III and compassionate-use data, with these newer agents in the treatment of MRSA and VRE infections are discussed.


CONCLUSIONS
The clinical experiences thus far with linezolid and quinupristin/dalfopristin for MRSA and VRE infections have demonstrated efficacy, making these agents important additions to the limited number of therapeutic alternatives for Gram-positive infections.
Noskin
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GA
Northwestern University Medical School, Division of Infectious Diseases, 251 E. Huron-Feinberg 16-704, Chicago, Illinois 60611, USA. gnoskin@northwestern.edu
D000081:Acetamides / Q000627:therapeutic use*; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D024901:Drug Resistance, Multiple, Bacterial; D016983:Enterococcus / Q000187:drug effects*; D016908:Gram-Positive Bacterial Infections / Q000188:drug therapy*; D006801:Humans; D000069349:Linezolid; D016106:Methicillin Resistance; D023303:Oxazolidinones / Q000627:therapeutic use*; D013203:Staphylococcal Infections / Q000188:drug therapy*; D013211:Staphylococcus aureus / Q000187:drug effects*; D020713:Vancomycin Resistance; D014769:Virginiamycin / Q000627:therapeutic use*
D000081:Acetamides; D000900:Anti-Bacterial Agents; D023303:Oxazolidinones; D014769:Virginiamycin; C062940:quinupristin-dalfopristin; D000069349:Linezolid