Approaches to serious methicillin-resistant Staphylococcus aureus infections with decreased susceptibility to vancomycin: clinical significance and options for management.
OBJECTIVE
This review addresses therapeutic approaches to Staphylococcus aureus infections with diminished susceptibility to vancomycin, focusing on recently published data in English language medical literature between June 2006 and July 2007.


RESULTS
Knowledge regarding the potential limitations of vancomycin therapy for S. aureus infections continues to emerge. Recent changes include alteration of the Clinical Laboratory and Standards Institute vancomycin breakpoint for S. aureus and questions regarding the utility of the lower breakpoint of 2.0 mg/l. Interest continues in the accessory gene regulator (agr) locus and its impact on the activity of vancomycin. Newer options for drug therapy progress, with strengths and limitations becoming more apparent for each.


CONCLUSIONS
Newer antimicrobial agents active against methicillin-resistant S. aureus such as daptomycin and linezolid continue to show value. Older antimicrobial agents may play an important therapeutic role and warrant further examination. Work is needed to evaluate current agents against methicillin-resistant S. aureus in the setting of elevated vancomycin minimum inhibitory concentrations or clinical failure. Antimicrobial selection for methicillin-resistant S. aureus infections with reduced susceptibility to vancomycin should be governed by disease severity, susceptibility patterns, knowledge of the limitations of current susceptibility testing, and strengths and weaknesses of the agents being considered.
Lewis
James S
JS
Department of Pharmacy, University Health System, San Antonio, Texas 78229-4493, USA. james.lewis@uhs-sa.com
Ellis
Michael W
MW
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D006801:Humans; D016106:Methicillin Resistance; D013203:Staphylococcal Infections / Q000188:drug therapy*; D013211:Staphylococcus aureus / Q000187:drug effects*; D020713:Vancomycin Resistance
D000900:Anti-Bacterial Agents