Development of Cheap and Simple Non-Proprietary Molecular Protocol to Detect Foodborne Pathogens in Alcohol-Free Beer

No- and low- alcohol beers (NABLABs) lack ethanol, an important preservative that helps prevent contamination with microbial pathogens. This study used a loop-mediated isothermal amplification (LAMP) assay to detect pathogens in beer. We applied the assay to five Salmonella serovars, three E. coli strains, and two Listeria monocytogenes strains in three styles of alcohol-free beer (lager, pale ale, and stout). The assay detected all pathogens tested in all the beer styles in less than 45 min. The assay itself was designed to be simple to perform, without the requirement for extensive training or complicated laboratory equipment. When testing was performed by local brewers in a blind trial, they were able to perform the assay competently and their results matched the anticipated results. Limits of detections were typically between 101–103 cfu/mL with better sensitivity for the Gram-negative pathogens. The sensitivity of the assay might be improved further with the incorporation of a pre-enrichment step.