Antimicrobial resistance among gram-positive organisms in the intensive care unit

The epidemiology of gram-positive pathogens in the intensive care unit are reviewed, recent trends in antimicrobial resistance among these organisms are discussed, and the significance of these data with respect to treatment are considered.

Results of surveillance studies published in 2001 and 2002 have demonstrated that gram-positive organisms such as Staphylococcus aureus, coagulase-negative staphylococci, and enterococci are among the most common bacteria infecting patients in intensive care units. Furthermore, these organisms are becoming increasingly resistant to available antimicrobial agents, and 2002 has ushered in worrisome developments such as the appearance of vancomycin-resistant S. aureus. Community-acquired methicillin-resistant S. aureus and the rise in incidence of vancomycin-resistant enterococci are other problems of great concern. Novel antibiotics such as quinupristin/dalfopristin and linezolid have activity against these agents, but resistance may develop to these agents as well. Studies have shown that infections caused by antibiotic-resistant organisms may be associated with increased morbidity, mortality, and costs. Exposure to antibiotics is a major risk factor for producing antibiotic resistance in patients, and methods to limit the spread of these organisms include restriction of antibiotic use, infection control, surveillance programs, and isolation procedures.

An awareness of the prevalence and patterns of resistance among gram-positive nosocomial pathogens is vital for the appropriate treatment of hospitalized patients. In addition, efforts must be made to minimize the selection and spread of these organisms.