Fast and Sensitive Swab-Based Bioluminescent Detection Method for Meat and Chicken Microbiological Contamination Using <i>Amydetes vivianii</i> Firefly Luciferase

New faster and more sensitive detection methods are required for food microbiological contamination quality control throughout the entire handling process. The adenosine triphosphate (ATP) bioluminescence detection method based on the firefly luciferin–luciferase system has been a widely used approach for decades due to its practicality, efficiency, and rapidity. The luciferase of the <i>Amydetes vivianii</i> firefly, cloned and produced in our laboratory, displays a high bioluminescence and stability, showing desirable properties for ATP assays. Using this enzyme, in this study we developed and validated a swab-based ATP detection method for meat, chicken, and milk, allowing us to distinguish between contaminated and non-contaminated forms of these foods. This method demonstrated robust interday and intraday precision, an accuracy of 70–71% across different matrices, and a limit of detection of 1.0 × 10⁴ cps for the dilutions and 2.7 × 10³ cps for the swabs, fulfilling all validation criteria and ensuring reliability for routine applications. Except for milk, which has very low endogenous ATP levels due to pasteurization, thus requiring sample pre-processing, the method allowed us to luminometrically detect ATP on the surface of meat and chicken in less than an hour using an assay solution. The method showed higher sensitivity compared to an available commercial kit due to its intense signal, with a remarkable ~22-fold increase in luminescence intensity when comparing the highest ATP concentration of <i>Amydetes</i> luciferase with a commercially available luciferase, allowing for detecting microbiological contamination at lower levels or using less sensitive luminometers.