Rapid detection of Listeria monocytogenes in dairy products by a novel chemilumonogenic approach

Food Microbiol. 2023 Feb:109:104150. doi: 10.1016/j.fm.2022.104150. Epub 2022 Sep 21.

Abstract

Routine monitoring of foodborne pathogens such as Listeria monocytogenes in food processing environments are time-consuming necessities to ensure food safety. Alternative rapid diagnostic methods for pathogen detection are increasingly used, but often demand specialized equipment, making them unsuitable for on-site testing. This short communication describes the successful demonstration of combining the sample preparation method Matrix-Lysis with a chemiluminescent based detection platform (AquaSpark™) for detection of L. monocytogenes in milk and yogurt. The proposed method was evaluated against qPCR resulting in 100% relative specificity for both foodstuffs and a relative sensitivity of 100% for milk as well as 96% for yogurt for bacterial levels >1 CFU/ml. Only at very low initial bacterial concentrations (<1 CFU/ml) diverging results were found highlighting the advantages and limitations of both methods. While being less susceptible to contamination and false positive results from non-growing or dead cells, qPCR had a slightly lower overall detection limit. However, it has to be pointed out that qPCR has an increased analytical cost and also requires an additional 24 h analysis time. This study demonstrates the first successful application of a chemilumonogenic detection approach for L. monocytogenes in food that has a high potential for on-site testing.

Keywords: AquaSpark; Listeria monocytogenes; Rapid methods; Sample preparation; qPCR.

MeSH terms

  • Animals
  • Dairy Products / microbiology
  • Food Microbiology
  • Listeria monocytogenes* / genetics
  • Milk / microbiology
  • Real-Time Polymerase Chain Reaction
  • Yogurt