Next Generation Qualitative In Vitro MRSA Diagnostic Test Approved

An accurate, on-demand, molecular test for methicillin-resistant Staphylococcus aureus (MRSA), which returns results within an hour, has been officially approved for use.

Emerging MRSA strains tend to elude detection from traditional assays and threaten the progress made against hospital-acquired infections in recent years and this new next generation qualitative test aims to fill this gap.


The new teat is based on a library of MRSA strains from around the world, covering more strains than existing tests. The test lowers the likelihood of false positives thanks to a new design incorporating updated polymerase chain reaction (PCR) primers and probes that detect different strains with mecA and mecC genes. The US Food and Drug Administration (FDA, Silver Springs, MD, USA) has approved a substantial Equivalence Determination for the test.

The Xpert MRSA NxG Assay (Cepheid, Sunnyvale, CA, USA) is performed on the GeneXpert Instrument Systems, is a qualitative in vitro diagnostic test intended for the detection of methicillin-resistant Staphylococcus aureus (MRSA) DNA directly from nasal swabs in patients at risk for nasal colonization. The test utilizes automated real-time polymerase chain reaction (PCR) for the amplification of MRSA-specific DNA targets and fluorogenic target-specific hybridization probes for the real-time detection of the amplified DNA. The Xpert MRSA NxG Assay is intended to aid in the prevention and control of MRSA infections in healthcare settings.

Fred C. Tenover, PhD, Cepheid's vice president for scientific affairs, said, “MRSA surveillance remains a critical infection prevention activity for healthcare facilities and one that is challenged by the continued evolution of target sequences within MRSA. Fortunately, our global MRSA surveillance initiative has helped us keep ahead of the curve by alerting us to the emergence of novel strain types, enabling us to design a more comprehensive assay that takes into account major shifts, like the emergence of mecC, as well as more subtle changes in the staphylococcal cassette chromosome mec (SCCmec) targets.”

Related Links:
US Food and Drug Administration
Cepheid