Vancomycin-resistant enterococcal bacteremia: comparison of clinical features and outcome between Enterococcus faecium and Enterococcus faecalis
Yen-Yi Chou, Te-Yu Lin, Jung-Chung Lin, Ning-Chi Wang, Ming-Yieh Peng, Feng-Yee Chang
Division of Infectious Diseases and Tropical Medicine, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
Received: January 10, 2007 Revised: April 27, 2007 Accepted: July 13, 2007
Background and purpose:
Vancomycin-resistant enterococci (VRE) have emerged as important nosocomial pathogens. This study was conducted to clarify the clinical features and outcome of patients with vancomycin-resistant enterococcal bacteremia.
Patients with vancomycin-resistant enterococcal bacteremia treated at a medical center in northern Taiwan between November 1998 and July 2006 were reviewed. Clinical and bacteriological characteristics of Enterococcus faecium and Enterococcus faecalis were compared.
Twelve patients (6 males and 6 females) were included for analyses. The mean age was 69.3 years (range, 40 to 86 years), and 8 cases (66.7%) were older than 65 years. All patients had underlying disease. Two patients received total hip replacement before development of VRE bacteremia. Twelve patients had prior exposure to broad-spectrum antimicrobial therapy. Ten patients had prior intensive care unit stay and prior mechanical ventilation before VRE bacteremia. All of the patients (n = 12) had an intravascular catheter in place. Bacteremia was caused by E. faecalis in 4 patients and by E. faecium in eight. The portals of entry included urinary tract (8.3%), skin, soft tissue and bone (41.7%) and unknown sources (50.0%). E. faecium showed a higher rate of resistance to ampicillin and teicoplanin than E. faecalis (87.5% vs 0.0%, p=0.01). The 60-day mortality rate was higher in patients with E. faecium bacteremia than E. faecalis bacteremia (62.5% vs 0.0%), although statistical significance was not obtained (p=0.08).
VRE bacteremia may have an impact on the mortality and morbidity of hospitalized patients. Patients with bacteremia caused by vancomycin-resistant E. faecium had a grave prognosis, especially immunosuppressed patients. The prudent use of antibiotics and strict enforcement of infection control may prevent further emergence and spread of VRE.
Bacteremia; Enterococcus faecalis; Enterococcus faecium; Vancomycin resistance
J Microbiol Immunol Infect. 2008;41:124-129.