Although many enterococcus
species can be held responsible for VRE, Enterococcus faecum and Enterococcus
faecalis constitute 95% of VRE infections.
We can add vancomycin
resistant strains such as E. gallinarus and E.casselflavius to
these, but these two organisms are more or less related to colonization. Their
pathogens are low and they can live in nature for years.
Vancomycin inhibits
enterococci by binding to the D-alanyl-D-alanine (D-Ala-D-Ala) terminal of cell
wall precursors.
In the case of residence,
the D-Ala-D-Ala terminus is replaced by the D-Ala-D-lactate termination. Vancomycin
binds to this end with low affinity. As a result, the MIC value for vancomycin
is almost 1000 fold.
The accepted MIC value for
vancomycin susceptibility is ≤4 mcg / mL, while the value that is resistant is
considered to be ≥32 mcg / mL. Values between
8-16 mcg / mL Vancomycin is considered to be intermediate, at which Vancomycin
is not preferred.
Pulse-field gel
electrophoresis (PFGE) is used in the analysis of both endemic and epidemic
clusters of VRE infection and colonization.
The vast majority of VREs
are Enterococcus faecum.
Risk factors
- Previous antibiotic therapy history is the most common risk factor for VRE. Vancomycin and cephaloporins are prominent antibiotics. Ceftazidime has been found one of the most prominent in a study.
- Administration of antibiotics for anaerobic treatment is known to increase the intensity of the fecal colonization of VRE, which decreases after the antibiotic is discontinued.
Patient characteristics
- More than 72 hours of hospital stay, important underlying medical conditions, need for ICU and invasive devices.
- Colonization pressure
- Exposure to contaminating surfaces
- Patient from care centers
The patient known to be
colonized with VRE is estimated to have been colonized for at least 1 year.
The percentage of VRE
infection development in patients who are contaminating with VRE is about 8%.
This rate is higher in severely ill patients and those with immunodeficiencies.
Routine surveillance
cultures are not recommended to detect colonized patients with VRE in
non-epidemic centers. Active surveillance cultures are recommended for
high-risk patients and are recommended for centers with increased frequency of
VRE.
The most important method
of protection is hand washing. In particular, it should be ensured that health
personnel take into account contact measures.
VRE hasta odasındaki
yüzeylerde saatlerce-günlerce kalabilmektedir.
VRE description: Vancomycin
resistance is defined as ≤ 16 mm by disc diffusion method or 8 μg / ml by agar
dilution method (MIC) or automated methods.
To say that there is an
epidemic; We need to show that in the healthcare facility, 3 or more infections
with clinical significance have been acquired within 7 days.
Optimal antibiotic
treatment in infected patients with VRE has not been definitively identified.
Linezolid is FDA approved. While quinopristin-dalfopristin has been FDA
approved in the past, this approval has been lifted due to ineffectiveness.
aminoglycosides.
E.faecalis, like E.
gallinarus and E.casselflavius, are generally susceptible to beta-lactams.
Linezolid, daptomycin and
tigecycline have activity against both E. faecium and E. faecalis.
