Vancomycin-Resistant Enterococci (VRE) Overview
Enterococci bacteria grabbed the attention of
public health officials
in the 1980s because of its ability to survive in humans and animals, and its
knack for sharing those survival tricks with other bacteria.
While enterococci are not as familiar as
or Escherichia coli (E. coli) bacteria, enterococci infections are among the most common type
acquired by hospitalized patients.
Enterococci, in general, are much less capable of causing disease than staph
or E. coli but still can complicate and prolong hospital stays. Virtually
the only people who develop illness from Enterococcus are
those who are already ill, such as individuals in a hospital intensive-care unit
or those who are elderly, have diabetes, have chronic kidney failure, and so forth. So,
unlike other forms of resistant bacteria, there is little chance or concern
among physicians of Enterococcus becoming epidemic in healthy
But enterococci are of great interest because, as with many of its
bacterial counterparts, it can resist and evade several forms of
antibiotic therapy, including
vancomycin, the antibiotic of last resort for resistant
Enterococcal infections that result in human disease can be fatal,
particularly those caused by strains of vancomycin-resistant enterococci (VRE). During 2004, VRE caused about one of
every three infections in hospital intensive-care units, according to the
Centers for Disease Control and Prevention (CDC).
In 1984, enterococci was given its own genus identity. In 1986, the
first VRE strains appeared in Europe and, in 1989, the first case of VRE was
reported in the United States. Between 1989 and 1993, the percentage of
enterococcal tests that were positive for VRE in the United States rose from 0.3
percent to 7.9 percent.
Researchers seek to develop improved therapeutics as
well as gain a better understanding of VRE's genetic survival characteristics
and how those resistance genes are passed to other pathogens.
Why is the latter element important? As of 2007, the United States had
reported seven cases of vancomycin-resistant Staphylococcus aureus (VRSA) infection, a serious development that has healthcare providers fearful of losing
ground in their attempt to control the spread of S. aureus. In one of the cases,
scientists confirmed the transfer of a key antibiotic resistance
gene from Enterococcus to Staphylococcus.