Development and evaluation of a Quadruplex Taq Man real-time PCR assay for simultaneous detection of clinical isolates of Enterococcus faecalis, Enterococcus faecium and their vanA and vanB genotypes.

Background and Objectives: We developed and evaluated the utility of a quadruplex Taqman real-time PCR assay that allows simultaneous identification of vancomycin-resistant genotypes and clinically relevant enterococci.
Materials and Methods: The specificity of the assay was tested using reference strains of vancomycin-resistant and susceptible enterococci. In total, 193 clinical isolates were identified and subsequently genotyped using a Quadruplex Taqman real-time PCR assay and melting curve analysis. Representative Quadruplex Taqman real-time PCR amplification curve were obtained for Enterococcus faecium, Enterococcus faecalis, vanA-containing E. faecium, vanB-containing E. faecalis.
Results: Phenotypic and genotypic analysis of the isolates gave same results for 82 enterococcal isolates, while in 5 isolates, they were inconsistent. We had three mixed strains, which were detected by the TaqMan real-time PCR assay and could not be identified correctly using phenotypic methods.
Conclusion: Vancomycin resistant enterococci (VRE) genotyping and identification of clinically relevant enterococci were rapidly and correctly performed using TaqMan real-time multiplex real-time PCR assay.