Evaluation of a vanA-specific PCR assay for detection of vancomycin- resistant Enterococcus faecium during a hospital outbreak

Abstract

We investigated the use of PCR as an alternative to culture of fecal samples for detection of vanA-containing Enterococcus faecium during a recent hospital outbreak. Rectal swabs collected consecutively from 223 patients were analyzed by culture with and without enrichment broth and by vanA- specific PCR of enrichment broth samples. Fifty-five specimens were positive for vanA-containing E. faecium by at least one method. The sensitivities of the vanA-specific PCR assay and agar culture with and without enrichment broth were 94.5, 98, and 89%, respectively. All three methods were 100% specific. Final results were obtained much more rapidly by PCR (within 24 to 30 h of specimen submission) than by the culture methods (4 to 5 days). Thus, PCR is an accurate and rapid alternative to culture for detection of vancomycin-resistant enterococci during hospital outbreaks.