News Feature | March 24, 2014

AdvanDx Files For FDA 510(k) Clearance For mecA XpressFISH

By Estel Grace Masangkay

AdvanDx announced that it has filed 510(k) clearance to the U.S. Food and Drug Administration (FDA) for its new new mecA XpressFISH test for fast detection of methicillin-resistant Staphylococcus aureus (MRSA) from S. aureus positive blood cultures.

mecA XpressFISH will enable physicians to rapidly identify methicillin-resistant staphylococcus aureus in patients and apply appropriate treatment for bloodstream infections. The assay is a qualitative fluorescence in situ hybridization (FISH) test that makes use of peptide nucleic acid (PNA) probes hybridizing to mecA messenger RNA (mRNA) sequences on blood cultures smears containing Staphylococcus aureus (SA).

MRSA is resistant to antibiotics often used to treat ordinary staphylococcal infections. Methicillin resistance is almost entirely caused by the presence and expression of the mecA gene encoding a unique penicillin-binding protein (PBP2a) which has low affinity for lactam drugs such as methicillin. Approximately more than 80,000 invasive MRSA infections occurred in the U.S. in 2011. 48,353 of these were categorized as healthcare associated community onset infections, while 14,156 were hospital-onset infections. 16,560 were community-associated infections, underlining the need for rapid detection.

Compared to conventional laboratory methods that can take up to 48 hours, mecA XpressFISH will allow labs to detect MRSA directly from blood cultures in about an hour. Its phenotypic mRNA-targeting approach makes the test unique in its MRSA identification mechanism, saving both patients and physicians priceless time, said the company.

James M. Coull, Ph.D, Chief Technology Officer for AdvanDx, said, “This is a significant breakthrough in how we identify MRSA. By targeting mecA mRNA, mecA XpressFISH rapidly detects the presence of the mecA gene, and determines whether the gene is transcriptionally functional and therefore able to confer resistance to broad classes of antibiotics, such as penicillins and cephalosporins. This information should help clinicians quickly determine the best course of antibiotic treatment.”

In addition to mecA XpressFISH, AdvanDx also markets QuickFISH platform for rapid identification of Gram-positive and Gram-negative bacteria, as well as PNA FISH for Candida species.