Acquisition and Duration of Vancomycin-Resistant Enterococcal Carriage in Relation to Strain Type

Abstract

In May 2000, the first outbreak of vancomycin-resistant Enterococcus faecium (VREF) was detected in the University Medical Center Utrecht in the nephrology ward. The question arose why some VREF strains spread among hospitalized patients, whereas other strains do not. Thirty patients who were found to be colonized with VREF between May and November 2000 were included in the study. Molecular typing confirmed that 19 of them carried an identical epidemic strain which harbored the esp gene while 11 were colonized by nonepidemic strains that were all esp negative. Acquisition of the outbreak strain was significantly associated with diabetes mellitus, renal transplantation, and extensive use of antibiotics, especially cephalosporins, in the 2-month period before the first isolation of VREF. To establish the duration of colonization, prospective surveillance of VREF carriage for a 6-month period starting from the first isolation of VREF was realized for 20 patients. After 6 months, VREF was still recovered from 60% of carriers of the outbreak strain versus 20% of carriers of nonepidemic strains (P < 0.01). However, antibiotic use during the follow-up period was significantly higher by carriers of the outbreak strain than by carriers of nonepidemic strains. The fact that the outbreak strain was recovered for a longer period of time than nonepidemic strains may facilitate dissemination of the strain. The results support a careful restrictive antibiotic policy for wards at risk for spread of VREF and implementation of isolation precautions for patients who are colonized with esp-positive outbreak strains.

Rapid Curbing of a Vancomycin-Resistant Enterococcus faecium Outbreak in a Nephrology Department

“…We confirmed such an association in univariate analysis, but, like other reports (11,17), we found that the only antibiotic group associated with VRE carriage by multivariate analysis was large-spectrum ␤-lactams. Some studies have shown a link between fluoroquinolones or antibiotics with activity against anaerobes and VRE carriage (2,18), but we did not confirm these associations in this outbreak mainly because very few patients received these compounds.…”

“…Numerous studies have identified antibiotic therapy as a risk factor for VRE acquisition (4,8,(11)(12)(13)(14)(15); however, controversies remain on the association between previous intravenous vancomycin use and VRE carriage (16). We confirmed such an association in univariate analysis, but, like other reports (11,17), we found that the only antibiotic group associated with VRE carriage by multivariate analysis was large-spectrum ␤-lactams.…”

Longer Intestinal Persistence of Enterococcus faecalis Compared to Enterococcus faecium Clones in Intensive-Care-Unit Patients

“…Different studies that have focused on the longitudinal follow-up of patients colonized with multiresistant enterococci, especially vancomycin-resistant isolates, demonstrated the prolonged persistence of vancomycin-resistant enterococci in the intestinal tract of hospitalized patients (3,22). Exposure to extendedspectrum cephalosporins and long ICU or hospital stays are commonly associated with prolonged colonization with multidrug-resistant enterococci (2, 4).…”

Prevalence, Virulence Factors and Antibiotic Susceptibilities of Enterococcal Isolates from Various Clinical Specimens in Coimbatore, Tamil Nadu

“…It was reported with resistance rates to ampicillin (7.4%), high-level gentamycin (15.0%) & streptomycin (27.9%), ciprofloxacin (37.9%) vancomycin (1.5%) and teicoplanin (1.5%). 21 Remarkably, the study confirmed, one enterococcal isolate resistant to vancomycin as well as to 3 more antibiotics such as amikacin, erythromycin and Cloxacil. The prevalence of vancomycin resistant enterococci (VRE) was noted to be less among pus derived enterococcal isolates and not significant when compared with other findings.…”