AdvanDx has submitted its new mecA XpressFISH™ test for the rapid detection of methicillin-resistant Staphylococcus aureus (MRSA) from S. aureus positive blood cultures to the U.S. Food and Drug Administration for 510(k) clearance. This assay will provide a way to  identify MRSA from positive blood cultures within about an hour, so helping to implement appropriate treatment for patients with bloodstream infections.

Methicillin-resistant Staphylococcus aureus (MRSA) is resistant to antibiotics commonly used to treat ordinary staphylococcal infections. An estimated 80,461 invasive MRSA infections occurred in the U.S. in 2011. Of these, 48,353 were healthcare associated community onset infections; 14,156 were hospital-onset infections; and 16,560 were community-associated infections.(1)

Methicillin-resistance is almost exclusively caused by the presence and expression of the mecA gene that encodes a unique penicillin-binding protein (PBP2a) that has low affinity for methicillin and other b-lactam drugs. mecA XpressFISH is a qualitative fluorescence in situ hybridization (FISH) assay that utilizes peptide nucleic acid (PNA) probes hybridizing to mecA messenger RNA (mRNA) sequences on smears from blood cultures containing Staphylococcus aureus (SA).  This “phenotypic” mRNA-targeting approach makes XpressFISH unique in its mechanism of MRSA identification.

“This is a significant breakthrough in how we identify MRSA,” says James M. Coull, Ph.D, Chief Technology Officer for AdvanDx. “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.”

mecA XpressFISH is the latest addition to AdvanDx’s easy-to-use, molecular-based diagnostics platform that provides rapid identification of bloodstream pathogens in minutes instead of days. AdvanDx also markets the QuickFISH platform for rapid identification of Gram-positive and Gram-negative bacteria as well as PNA FISH for Candida species.

Since 2003, the use of AdvanDx’s flagship product, PNA FISH for rapid identification of staphylococcal bloodstream pathogens has dramatically improved therapy decisions and outcomes for patients with bloodstream infections by helping physicians and pharmacists optimize antibiotic therapy earlier. A clinical study performed at the Washington Hospital Center (Washington, D.C.) demonstrated that rapid identification and notification of PNA FISH results reduced ICU and overall mortality rates by 82% and 53% respectively, while reducing antibiotic use for patients with CNS positive blood cultures. In a separate study performed at the University of Maryland Medical Center (Baltimore, MD) rapid PNA FISH results, helped reduce unnecessary vancomycin use by 4.5 doses, length of stay by 2 days and hospital costs by $4,005 for patients with CNS contaminated blood cultures. (2,3)

For more information visit www.AdvanDx.com.