NEW YORK (GenomeWeb News) – Molecular diagnostics firm AdvanDx today announced it submitted a 510(k) application to the US Food and Drug Administration for clearance of its mecA XpressFISH test for the rapid detection of methicillin-resistant Staphylococcus aureus from S. aureus-positive blood cultures.
The test is a qualitative fluorescence in situ hybridization assay that uses peptide nucleic acid probes that hybridize to mecA mRNA sequences on smears from blood cultures containing S. aureus. The presence and expression of the mecA gene encoding a penicillin-binding protein with low affinity for methicillin and other b-lactam drugs is almost always the cause of methicillin resistance, Woburn, Mass.-based AdvanDx said. Its "phenotypic" mRNA-targeting approach, it added, makes the mecA Xpress FISH test "unique in its mechanism of MRSA identification."
The test allows laboratories to detect MRSA directly from S. aureus-positive blood cultures in about one hour, compared to the 48 hours it can take with conventional lab methods, the company said. As a result clinicians using the test would be able to determine an appropriate therapy more rapidly for MRSA-infected patients.
"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." AdvanDx Chief Technology Officer James Coull said in a statement. "This information should help clinicians quickly determine the best course of antibiotic treatment."