Overview
What VRE Means Clinically
Vancomycin resistant enterococci (VRE) are usually Enterococcus faecium or Enterococcus faecalis that have acquired vanA or vanB genes.
Vancomycin-resistant enterococci (VRE) are usually *Enterococcus faecium* or *Enterococcus faecalis* that have acquired vanA or vanB genes. These genes change the bacterial cell-wall target so vancomycin binds poorly. In laboratory terms, the isolate has a vancomycin minimum inhibitory concentration (MIC) greater than 8 µg/mL. *E. gallinarum* and *E. casseliflavus*, which have a different intrinsic resistance pattern, are excluded from this definition. Enterococci may live in the gastrointestinal tract without causing illness. That state is colonization: a screening or clinical specimen is positive, but the patient has no compatible signs of infection. Colonization can provide a reservoir for transmission, but antibiotics do not eradicate it and are not indicated solely because the culture is positive. Infection occurs when VRE is causing disease at a clinical site, such as the urinary tract, wound, abdomen, bloodstream, or cardiac valves. The same organism can therefore produce two very different nursing priorities: a stable patient with carriage needs transmission prevention, whereas a patient with VRE bacteremia and hypotension needs immediate sepsis management, cultures, source control, and antimicrobial therapy. Prolonged hospitalization, previous broad-spectrum antibiotic exposure, immunosuppression,...