LIAISON PLEX Gram-Positive Blood Culture Assay

The LIAISON PLEX Gram-Positive Blood Culture Assay is an automated, qualitative multiplexed nucleic acid test that detects and identifies gram-positive bacteria and antimicrobial resistance markers (mecA/mecC, vanA, vanB) directly from positive blood culture bottles. It performs non-amplified, direct detection using microarray-based hybridization and is performed on the LIAISON PLEX System for rapid sample-to-answer analysis to aid diagnosis of bacterial bloodstream infections.

Like the predicate VERIGENE BC-GP assay, the LIAISON PLEX BCP uses automated sample-to-answer processing and detects the same bacterial targets and resistance markers. Both are non-amplified, direct detection methods performed on positive blood cultures. The LIAISON PLEX uses microarray-based hybridization with gold nanoparticle probes and silver enhancement on a different instrument platform (LIAISON PLEX vs. VERIGENE), but achieves functionally equivalent organism identification and resistance detection.

ISO 14971:2019 (risk management), IEC 62366-1:2015 (usability engineering), ISO 62304:2006 (software lifecycle), ISO 13485:2016 (quality management), ISO 20916:2019 (clinical performance studies), CLSI EP12-A2 (qualitative test evaluation), CLSI EP25-A (reagent stability), EN ISO 18113 series (IVD labeling), IEC 61010 and IEC 60601-1-2 (safety and EMC), and FDA Class II Special Controls Guideline for Multiplex Nucleic Acid Assays.

Substantial equivalence is established because both devices: (1) target identical bacterial genera/species and resistance markers using nucleic acid detection; (2) operate as non-amplified, direct detection assays on positive blood cultures; (3) achieve comparable clinical performance (sensitivity/specificity >96% for most targets); and (4) use the same specimen type and intended use. Although the LIAISON PLEX employs a different platform and detection chemistry (microarray/nanoparticles vs. predicate), the analytical and clinical results are equivalent, with no new safety or effectiveness concerns introduced by the technology change.