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Abstract
Existing challenges with the control of Salmonella and Campylobacter in poultry demand the adoption of rapid yet accurate pathogen quantification platforms to ensure safety of poultry and poultry meat products in a timely manner. Despite the availability of rapid and automated quantification methods for Salmonella and Campylobacter, limited information is available on the accuracy and use of these methods in determining poultry food safety. This study was conducted to compare the performance of rapid and automated quantification methods with culture-based methods for quantifying Salmonella and Campylobacter in raw poultry. Naturally contaminated carcass/parts rinses collected at various stages of poultry processing and laboratory inoculated chicken wings subjected to different concentrations of peracetic acid (PAA) were used for the quantitative analysis of Salmonella and Campylobacter. Salmonella concentrations in naturally contaminated samples were compared using PCR-based quantification assay and miniaturized most probable number (mMPN) method, while PCR-based quantification assay and direct plating were used for artificially inoculated chicken wings. Comparison was performed between an automated MPN method and direct plating to determine Campylobacter in naturally contaminated and artificially inoculated raw poultry. The mMPN method resulted in higher Salmonella levels as compared to PCR-based quantification assay at all stages of poultry processing (p ≤ 0.05), whereas PCR-based assay overestimated Salmonella populations on inoculated samples irrespective of antimicrobial treatment (p ≤ 0.05). A good correlation (r) of 0.71 and 0.65 was observed between rapid and conventional methods for enumerating Salmonella in naturally and artificially contaminated samples, respectively. Automated MPN and direct plating method were similar (p > 0.05) in quantifying Campylobacter levels in naturally and artificially contaminated poultry treated with different concentrations of PAA. Correlation and Bland-Altman analysis showed a high correlation (r > 0.90) between automated MPN and direct plating method for enumerating Campylobacter in naturally and artificially contaminated poultry, suggesting a good agreement between two methods. Current study demonstrated that the automated MPN method can be reliably used to evaluate food safety risk associated with Campylobacter¬ in poultry while, the PCR-based quantification assay can be useful in assessing risk associated with low levels of Salmonella in poultry.