SuperbugsNew test for detecting newly emerging strains of drug-resistant superbug

Published 14 January 2014

Molecular assays for MRSA are used in active surveillance programs to identify colonized patients rapidly. Active surveillance is a proven strategy to reduce transmission in healthcare settings and it helps prevent infection in vulnerable patients. BD Diagnostics has received FDA clearance to market the BD MAX MRSA XT Assay for use on the BD MAX System. This is the second assay from BD Diagnostics capable of detecting newly emerging MRSA strains with the novel mecC gene.

BD Diagnostics the other day announced it has received FDA clearance to market the BD MAX MRSA XT Assay for use on the fully-automated BD MAX System. This is the second assay from BD Diagnostics capable of detecting newly emerging MRSA strains with the novel mecC gene.

The BD MAX StaphSR Assay, launched in 2013, reports results for both Staphylococus aureus (SA) and methicillin-resistant Staphylococus aureus (MRSA), and the company says it was the first commercially available assay in the United States to detect mecC strains of MRSA. Both assays use eXTended Detection Technology to identify a broad range of SA strains, including mecA and mecC dropout mutants and new strains of MRSA that may not be detected by other assays.

Assay design is critical to detect MRSA accurately and ensure appropriate infection control interventions are applied,” said Dr. Patrick Murray, Worldwide Director of Scientific Affairs at BD Diagnostics-Diagnostic Systems. “The BD MAX MRSA XT Assay helps improve patient safety by providing hospitals with a new solution to detect the latest strains of this drug-resistant superbug.”

Molecular assays for MRSA are used in active surveillance programs to identify colonized patients rapidly. Active surveillance is a proven strategy to reduce transmission in healthcare settings and it helps prevent infection in vulnerable patients. Inaccurate detection may contribute to uncontrolled transmission of MRSA and inappropriate use of healthcare resources. With many commercial assays, SA strains carrying SCCmec where the mecA gene is absent (commonly called “dropout mutants”) may be incorrectly classified as MRSA. These false positive results can lead to unnecessary and expensive isolation and treatment of patients.

MRSA strains with the newly emerging mecC gene account for nearly 3 percent of all new MRSA cases in some communities but cannot be detected by all assays. These false negative results can lead to uncontrolled transmission of undetected strains of MRSA.

BD says that the BD MAX MRSA XT Assay is the latest in a series of assays developed by BD to help detect and prevent healthcare-associated infections (HAIs). Other HAI assays available on the BD MAX System include BD MAX Cdiff for the detection of toxigenic Clostridium difficile DNA, and BD MAX StaphSR.