Analytical Validation and Preliminary Diagnostic Performance Evaluation of GenoPATHX™ Multiplex qPCR for Quantitative Detection of Key Salmonella Serovars in Poultry Matrices.

Rapid detection and quantification of epidemiologically important Salmonella enterica serovars are critical for poultry surveillance, food safety monitoring, and risk-based intervention strategies. This study performed comprehensive analytical validation together with a preliminary field-based diagnostic performance evaluation of GenoPATHX™, a multiplex probe-based qPCR platform designed for the simultaneous detection and quantification of priority Salmonella serovars in poultry-associated matrices. The platform consists of two multiplex panels, designated the Chicken Key Performance Indicator (CKPI) and Turkey Key Performance Indicator (TKPI), each designed to detect priority poultry-associated Salmonella serovars together with a genus-level S. enterica marker. Analytical performance was evaluated for amplification efficiency, linearity, limit of detection (LoD95), limit of quantification (LoQ), repeatability, intermediate precision, analytical specificity (inclusivity/exclusivity), robustness, matrix effects, and performance in artificially inoculated matrices. Diagnostic performance was further assessed using naturally contaminated poultry environmental samples. The assay demonstrated robust amplification performance in both singleplex and multiplex formats, with high linearity (R2 = 0.987-0.999) and LoD95 values ranging from 60 to 545 genome equivalents per reaction. Complete analytical inclusivity and high exclusivity were achieved for the evaluated isolate panel. In field samples, the direct GenoPATHX™ workflow demonstrated 81.0% sensitivity, 91.3% specificity, and substantial agreement with the USDA-FSIS reference culture method (κ = 0.73). Overall, GenoPATHX™ exhibited robust analytical performance and enabled rapid, same-day quantitative detection of priority Salmonella serovars in poultry-associated matrices, supporting its application for poultry surveillance and food safety monitoring.