Comparison of media for the detection of campylobacter jejuni using a commercial RT-PCR system

Authors: OLSEN, ELENA - University Of Wisconsin; BODIE, AARON - University Of Georgia; TARCIN, HALEY - University Of Wisconsin; RUBINELLI, PETER - University Of Arkansas; APPLEGATE, SAVANNAH - Hygiena, Llc; STEPHENS, TYLER - Micro Environ Tech, Llc; Rothrock Jr, Michael; RICKE, STEVEN - University Of Wisconsin

Submitted to: Pathogens
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/6/2025
Publication Date: 2/8/2025
Citation: Olsen, E.G., Bodie, A.R., Tarcin, H.A., Rubinelli, P.M., Applegate, S.H., Stephens, T.P., Rothrock Jr, M.J., Ricke, S.C. 2025. Comparison of media for the detection of campylobacter jejuni using a commercial RT-PCR system. Pathogens. https://doi.org/10.3390/pathogens14020166.
DOI: https://doi.org/10.3390/pathogens14020166

Interpretive Summary: The accurate and rapid detection of Campylobacter jejuni is critical for ensuring food safety in poultry production. This study evaluated the performance of the BAX Q7-RT PCR system in detecting C. jejuni across three enrichment media: Mueller Hinton Broth (MHB), Bolton’s Blood-Free Broth (BFBB2x), and Buffered Peptone Water (BPW). Detection limits, enumeration ranges, and statistical metrics including R2 and Root Mean Square Error (RMSE) were assessed to determine system reliability. Linear regression analysis revealed strong correlations between bacterial concentrations and CT values, with R2 values of 0.98, 0.95, and 0.92 for MHB, BFBB2x, and BPW, respectively. Detection limits were lowest in MHB (2.56 log10 CFU/mL), followed by BFBB2x (2.93 log10 CFU/mL) and BPW (3.03 log10 CFU/mL). Enumerable ranges were broader with BAX Q7 estimates compared to plate counts, with MHB exhibiting the highest sensitivity and precision. Statistical criteria (R2 > 0.80, RMSE < 0.60, and enumerable ranges of 4.00–8.00 log10 CFU/mL) were applied to validate linear-fit equations, ensuring reliability in quantification. The results underscore the importance of media selection and adherence to statistical benchmarks for optimizing detection performance. The BAX Q7-RT PCR system demonstrated high precision and efficiency, particularly with MHB, making it a reliable tool for routine detection of C. jejuni in poultry rinsates and other associated matrices. These findings support its integration into food safety workflows, enabling rapid and accurate monitoring of microbial contamination in poultry production environments.

Technical Abstract: The accurate and rapid detection of Campylobacter jejuni is critical for ensuring food safety in poultry production. This study evaluated the performance of the BAX Q7-RT PCR system in detecting C. jejuni across three enrichment media: Mueller Hinton Broth (MHB), Bolton’s Blood-Free Broth (BFBB2x), and Buffered Peptone Water (BPW). Detection limits, enumeration ranges, and statistical metrics including R2 and Root Mean Square Error (RMSE) were assessed to determine system reliability. Linear regression analysis revealed strong correlations between bacterial concentrations and CT values, with R2 values of 0.98, 0.95, and 0.92 for MHB, BFBB2x, and BPW, respectively. Detection limits were lowest in MHB (2.56 log10 CFU/mL), followed by BFBB2x (2.93 log10 CFU/mL) and BPW (3.03 log10 CFU/mL). Enumerable ranges were broader with BAX Q7 estimates compared to plate counts, with MHB exhibiting the highest sensitivity and precision. Statistical criteria (R2 > 0.80, RMSE < 0.60, and enumerable ranges of 4.00–8.00 log10 CFU/mL) were applied to validate linear-fit equations, ensuring reliability in quantification. The results underscore the importance of media selection and adherence to statistical benchmarks for optimizing detection performance. The BAX Q7-RT PCR system demonstrated high precision and efficiency, particularly with MHB, making it a reliable tool for routine detection of C. jejuni in poultry rinsates and other associated matrices. These findings support its integration into food safety workflows, enabling rapid and accurate monitoring of microbial contamination in poultry production environments.