Digital PCR assay for the specific detection and estimation of contamination levels in poultry rinse.

Strains of are a frequent cause of foodborne illness and are known to contaminate poultry products. Most testing methods can qualitatively detect and cannot quantify or estimate the load in samples. Therefore, the aim of this study was to standardize and validate a partitioned-based digital PCR (dPCR) assay for the detection and estimation of contamination levels in poultry rinses. Pure culture strains were cultured, enumerated, cold-stressed for 48 h, and used to inoculate whole carcass chicken rinse (WCCR) at 1-4 log CFU/30 mL and enriched at 37 °C for 5 h. Undiluted DNA samples with primer and probes targeting the -specific gene were used for the dPCR assay. The dPCR assay was highly specific, with a limit of detection of 0.001 ng/μL and a limit of quantification of 0.01 ng/μL. The dPCR assay further showed no PCR reaction inhibition up to 5 μg of crude DNA extract. The assays accurately detected all cold-stressed in inoculated WCCR samples following a 5-h enrichment. Most importantly, when converted to log, the dPCR copies/μL values accurately estimated the inoculated levels. The dPCR assay standardized in this study is a robust method for the detection and estimation of concentration in contaminated food samples. This approach can allow same-day decision-making for poultry processors attempting to maintain limits and controls on contamination.