Mise au point d’une méthode d’évaluation du risque bactérien par une approche a priori

Abstract

The objective of this study is, firstly, to emphasize the importance of adopting a microbiological risk assessment system and secondly, to evaluate the MALDI-TOF MS method as an effective and rapid tool for the identification of foodborne bacterial isolates. The microbiological analyzes results of the reconstituted pasteurized milk samples, collected at different stages of their manufacturing process, compared to the compliance limits indicated in the microbiological standards related to dairy products and derived products from the Algerian regulations in force, showed compliance at the level of the FAM, the search for other germs (Total and faecal Coliform , Clostridium sulfito-réducteur, Salmonella sp and Staphylococcus aureus) are revealed negative in these samples. However, contamination with coagulase-negative staphylococci species was detected. In this study, 12 bacteria species isolated from the same milk samples are identified by MALDI-TOF MS confronted with the 16S rDNA as a reference method. Our results shows high reliability of MALDI-TOF MS identification at the species level covering all isolates (100%) with a score >2. This study suggests that compared to the sequencing of the 16S rDNA gene that provides limited results; MALDI-TOF MS and bioinformatic analysis can be used for rapid and accurate identification of spoilage agents and pathogens in the dairy industry. These tools, once integrated with the implementation of preventive systems such as the HACCP, will significantly improve food security.