Predictors and Outcome Associated with an Enterococcus Positive Isolate During Intensive Care Unit Admission (Report‪)‬

Enterococci are Gram-positive bacterial commensals of the gastrointestinal and female genital tracts of humans. Enterococcus faecalis and E. faecium are usually considered organisms of relatively low virulence, although invasion can result in urinary tract infections, endocarditis, bacteraemia, meningitis and intra-abdominal infections (1). Enterococcus spp. are common nosocomial pathogens in the USA, responsible for three to four cases of nosocomial bloodstream infections per 10,000 hospital discharges (2), and the third most common cause of bloodstream infections reported in combined medical-surgical intensive care units (ICU) (3). Since the isolation of vancomycin-resistant enterococci (VRE) in Europe in 1987 (4), the organism has emerged as one of the most feared nosocomial pathogens. Recently published guidelines from the Infectious Diseases Society of America strongly advocate against empiric therapy directed at enterococci because of concerns about antimicrobial resistance (5). Cefepime (FEP) and piperacillin-tazobactam (TZP) are commonly used alternatives for the [beta]-lactam component of broad-spectrum regimens for empiric treatment of sepsis in the critically ill. Concerns about the relative activity against Enterococcus spp. of FEP (minimal inhibitory concentration [MIC] = 4 to 12 mg/l), compared to TZP (MIC = 0.4 to 1.6 mg/l for piperacillin), carbapenems (MIC = 1 to 2 mg/l for imipenem), ampicillin (AMP) (MIC = 1 to 5 mg/l against E. faecalis, although E. faecium is commonly resistant) and vancomycin (MIC = 0.2 to 6 mg/l) (6) means that some clinicians routinely add anti-enterococcal cover to FEP therapy for suspected intra-abdominal sepsis. In this study, we analysed the incidence of enterococcal colonisation and/or infection and the risk factors for a positive enterococcal isolate and in-hospital mortality, with particular reference to empiric antibiotic therapy (7).