Recovery Of Vancomycin-resistant Enterococci Research Articles

Recovery of Both Vancomycin-Resistant Enterococci and Methicillin-ResistantStaphylococcus aureusFrom Culture of a Single Clinical Specimen From Colonized or Infected Patients

To describe the incidence of recovery of both vancomycin-resistant enterococci (VRE) and methicillin-resistant Staphylococcus aureus (MRSA) from culture of a single clinical specimen, to describe the clinical characteristics of patients from whom these specimens were recovered, and to identify the risk factors of these patients. A retrospective cohort and case-control study. A tertiary care university hospital and referral center in Seoul, Korea. We identified 61 case patients for whom a single clinical specimen yielded both VRE and MRSA on culture, and 122 control patients for whom any clinical specimen yielded only VRE on culture. The control patients were selected by matching 2:1 with the case patients for age, sex, and first date of sampling that led to isolation of VRE or both VRE and MRSA among 1,536 VRE-colonized patients from January 1, 2003, through December 31, 2006. To identify patient risk factors for the recovery of both VRE and MRSA in a single clinical specimen, we performed univariate comparisons between the 2 groups and then multivariate logistic regression analysis. The incidence of recovery of both VRE and MRSA from culture of a single clinical specimen was 3.97% (for 61 of 1,536 VRE-colonized patients) over 4 years. Among these 82 single clinical specimens, the most common type was wound specimens (26.8%), followed by lower respiratory tract specimens (18.3%), urine specimens (17.1%), and catheter tips (15.9%). Of the 61 case patients, 14 (23.0%) had 2 or more single clinical specimens that yielded both VRE and MRSA on culture, and the longest interval from the first sampling that yielded both organisms to the last sampling that yielded both was 174 days. Independent patient risk factors for the presence of both VRE and MRSA in a single clinical specimen were chronic renal disease (odds ratio [OR], 7.00; P=.012 ), urinary catheterization (OR, 3.36; P=.026), and longer total cumulative duration of hospital stay within the previous year (OR, 1.03; P < .001). We confirmed that the recovery of VRE and MRSA from a single clinical specimen occurs continually. Because prolonged cell-to-cell contact can facilitate transfer of vanA, close observation and surveillance for vancomycin-resistant S. aureus, especially among patients with risk factors for the recovery of both VRE and MRSA from a single clinical specimen, should be continued.

Distribution and genetic relatedness of vancomycin-resistant enterococci (VRE) isolated from healthy slaughtered chickens in Hungary from 2001 to 2004

The presence of the vanA gene was determined in enterococci from healthy poultry, originating from the Hungarian resistance monitoring system between 2001 and 2004. Enterococci (n = 562) were collected from intestinal samples of slaughtered broiler chickens. The presence of van genes was detected by polymerase chain reaction (PCR). The vancomycin-resistant enterococcus (VRE) strains carried only the vanA gene. Genus- and species-level identification of the vanA gene carrier strains was carried out by PCR using specific primers. In 2001, 25 out of the 289 isolated strains (8.6%) were vanA carriers (1 Enterococcus mundtii, 13 E. durans and 11 E.faecium). In 2002 (n = 87), 20 (23%) strains were vanA positive (11 E. durans and 9 E. faecium). In 2003 and 2004, none of the strains (n = 95 and 91, respectively) were positive for the most common van genes. In 2003, there was only one strain for which higher minimum inhibitory concentrations (MIC) of vancomycin (4 mg/L) and teicoplanin (8 mg/L) were found. In 2004 there were three strains for which the MIC of vancomycin was 8 mg/L, and 2 strains and 1 strain with teicoplanin MICs of 4 mg/L and 8 mg/L, respectively. The potential similarity of these strains was studied by pulsed-field gel electrophoresis (PFGE). The VRE strains were not closely related to one another. The annual data of vancomycin resistance indicate an association between the recovery of vancomycin-resistant enterococci and the use of avoparcin in animal feeds. This study indicates that with the reduced use of antibiotics in food animals, it is possible to decrease the rate of resistant bacteria. Although the use of avoparcin had been banned in 1998, the VRE strains disappeared only five years later.

Antimicrobial susceptibility of enterococci strains isolated from slaughter animals on the data of Hungarian resistance monitoring system from 2001 to 2004

Isolates of Enterococcus spp. were collected from January 2001 to December 2004 from caecal samples of slaughtered poultry, swine and cattle in Hungary. The isolates were identified by their growth and biochemical properties and with PCR. The antibiotic susceptibility of a total number of 1272 isolates was tested with disk diffusion test to ampicillin, gentamicin, streptomycin, tetracycline, erythromycin and vancomycin. It was established that although ampicillin and amoxicillin are often used in veterinary practice its resistance rate was relatively low. In the case of tetracyclines and macrolides, a high incidence of resistance was found. Susceptibility of strains to tetracyclines and/or macrolides reduced in both 2003 and 2004 in all animal species, which may be due to the more frequent usage of these drugs in the veterinary practice following the ban of growth promoters. The annual data of vancomycin resistance point to an association between the recovery of vancomycin-resistant enterococci (VRE) isolates and the use of avoparcin. This study indicates that reducing antimicrobial resistance in food animals could be possible with lower usage of antibiotics, although variations can occur with different strains.

Preventing the influx of vancomycin-resistant enterococci into health care institutions, by use of a simple validated prediction rule.

The goal of this study was to develop a validated prediction rule for identification of patients harboring vancomycin-resistant enterococci (VRE) at hospital admission. A model for the prediction of patients harboring VRE at admission was created and validated by assigning weighted point values to independent risk factors associated with harboring VRE at admission, in 2 different cohorts of patients from 2 tertiary care hospitals in Boston, Massachusetts. Patients with VRE isolated from clinical culture samples collected within 48 h of hospital admission were compared with patients not harboring VRE. To assess the diagnostic accuracy of the prediction rule, the main outcome measures were patient demographic characteristics, comorbid illnesses, hospitalizations, and antibiotic exposure. A total of 412 patients were enrolled. A risk index score was derived by using the following 6 independent risk factors associated with VRE recovery within 48 h of hospital admission: previous isolation of methicillin-resistant Staphylococcus aureus (MRSA), whether the patient was receiving long-term hemodialysis, transfer from a long-term care facility, antibiotic exposure, prior hospitalization, and age >60 years. On the basis of a point score >or=10, the sensitivity, specificity, and positive and negative predictive values of this prediction rule were 44%, 98%, 81%, and 90%, respectively. This validated clinical prediction rule provides a novel strategy for the identification of patients at high risk of harboring VRE at hospital admission. Implementation of this rule may reduce the influx of VRE into health care institutions and the overall prevalence of VRE, by targeting VRE-screening measures and contact isolation precautions for these high-risk patients.

Recovery of Vancomycin-Resistant Enterococci on Fingertips and Environmental Surfaces

Recovery of Vancomycin-Resistant Enterococci on Fingertips and Environmental Surfaces