[An analysis of 182 enterococcal bloodstream infections: epidemiology, microbiology, and outcome]

Abstract

Introduction: Enterococcal bloodstream infections have acquired considerable importance in recent years, mainly because of the increasing number of cases that occur during hospital admission.

Methods: Retrospective study of the clinical records of patients diagnosed with enterococcal bacteremia and hospitalized over a 12-year period (January 1994-April 2006), analyzing epidemiological, clinical and microbiological characteristics, outcome and prognostic factors.

Results: A total of 182 episodes of bacteremia were recorded; 68% of them were nosocomial infections, accounting for 5% of the in-hospital bacteremia episodes in this period. The most frequent sources of infection were urinary tract (29%), cardiovascular (25%), intra-abdominal (21%) and primary bacteremia (12%). Associated comorbid conditions were present in 85% of patients, mainly neoplasms (33%). Enterococcus faecalis was responsible for 70% of cases, E. faecium 22%, and other species of enterococci 8%. Twenty percent were polymicrobial bacteremia. Antibiotic resistance was documented in 23% of the strains: 14% ampicillin, 8% gentamicin, 3% ampicillin and gentamicin, and 0.5% vancomycin. Overall mortality was 31%. Polymicrobial bacteremia and comorbidity were associated with a poor prognosis.

Conclusion: In our hospital, Enterococcus is the fifth most frequent cause of nosocomial bacteremia. E. faecium is characterized by a high incidence (more than 50% of cases) of ampicillin resistance.