A new multiplex PCR assay for the simultaneous detection of vancomycin-resistant enterococci from rectal swabs

Accepted 24 February 2010. published online 29 March 2010.

Summary

Objectives

This study describes the diagnostic performance of a recently available multiplex PCR-based kit for the simultaneous detection and identification of Enterococcus faecium, Enterococcus faecalis, vanA, vanB, vanC1 and vanC2/C3 genes, directly from rectal swabs constituting the most complete existing molecular assay currently available.

Methods

The diagnostic performance of this assay was evaluated by a multicenter study involving three independent public hospitals and consisted in the analysis of 187 rectal swabs from patients at high risk for vancomycin-resistant enterococci colonization.

Results

When bacteria culture was used as the gold standard, the sensitivity, specificity, positive and negative predicted values for the assay were 96.8%, 76.0%, 67.7% and 97.9%, respectively. When a composite reference standard consisting of culture and DNA sequencing of PCR products was used as the gold standard, the sensitivity, specificity, positive and negative predicted values for the PCR-based assay were 97.8%, 96.9%, 96.7% and 97.9%, respectively.

Conclusions

Based on these results, we conclude that this assay is considerably more sensitive than traditional microbiological methods for detecting vancomycin-resistant enterococci from rectal swabs. It is also much faster than culture. We believe that the implementation of this assay in routine clinical laboratories could help to reduce hospital-acquired vancomycin-resistant enterococci infections.

Keywords: Vancomycin-resistant enterococci, Molecular biology assay, Multiplex PCR, In vitro diagnostics, Control of hospital-acquired infections

a Laboratorio de Microbiología, Roberto del Rio Hospital, Zañartu Ave. 1085, Santiago, Chile

b Laboratorio de Microbiología, Barros Luco Trudeau Hospital, José Miguel Carrera Ave. 3204, Santiago, Chile

c Departamento de Investigación y Desarrollo, TAAG Genetics S.A., Antonio Bellet 77, Of. 703. Providencia, Santiago, Chile

d Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Alameda 340, Santiago, Chile

Corresponding author. Tel.: +56 2 264 38 76, fax: +56 2 264 27 95.

PII: S0163-4453(10)00054-X

doi:10.1016/j.jinf.2010.02.011

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