Detection of vanA genes in vancomycin-susceptible Enterococcus faecium isolates: implications for additional testing

To assess the frequency of silent vancomycin resistance, phenotypically susceptible Enterococcus faecium isolates underwent genotypic testing using Cepheid's Xpert vanA/vanB PCR. A total of 6% of isolates had silent vanA genes. However, the clinical relevance of silent van genes and the lack of rapid, random-access genotypic methods poses an ongoing challenge to laboratories.