Antibiotic-resistant enterococci and the changing face of surgical infections

Background: Enterococci have not been thought to play an important role in intra-abdominal infections because of their relatively low virulence. However, this notion is changing because of the recent emergence of these microbes as significant nosocomial pathogens. Objectives: To review the mechanisms of antibiotic resistance of enterococci and to discuss the significance of multidrug-resistant enterococci in surgical infections. Data Sources: Medical and basic science literature relating to enterococci. Data Synthesis: In addition to having intrinsic resistance to a number of antibiotics, enterococci have the ability to acquire resistant genes through the exchange of plasmids or transposons from other bacterial species. Moreover, enterococci have been shown to transmit these genes to other bacterial species in turn. The extensive resistance of these microorganisms has led to their emergence as significant nosocomial pathogens, ranking second only to Escherichia coli in the number of pathogenic isolates recovered from patients in intensive care units. There has also been a marked increase in vancomycin-resistant enterococcal infections in surgical patients in the last 5 years. Some studies associate the prior use of vancomycin or third-generation cephalosporins with the emergence of these strains. Overall, enterococcal infections are associated with increased morbidity and mortality. Conclusions: In view of the marked resistance of enterococci to antibiotics and their ability to disseminate resistance genes, these microbes have become important pathogens. Enterococci pose a threat to surgical patients, often causing significant therapeutic dilemmas.