Adaptive strategies of Listeria monocytogenes: An in-depth analysis of the virulent strain involved in an outbreak in Italy through quantitative proteomics

• Published in: International journal of food microbiology 2025-01, Vol.427, p.110951, Article 110951
• Main Authors: Luciani, Mirella, Krasteva, Ivanka, Schirone, Maria, D'Onofrio, Federica, Iannetti, Luigi, Torresi, Marina, Di Pancrazio, Chiara, Perletta, Fabrizia, Valentinuzzi, Silvia, Tittarelli, Manuela, Pomilio, Francesco, D'Alterio, Nicola, Paparella, Antonello, Del Boccio, Piero
• Format: Article
• Language: English
• Subjects: Adaptative response; Bioinformatic; bioinformatics; food microbiology; food safety; foodomics; Italy; Listeria monocytogenes; Listeriosis; molecular epidemiology; Pathogen; protein synthesis; Proteome; proteomics; Stress factors; virulence; virulent strains
• ISSN: 0168-1605; 1879-3460; 1879-3460
• DOI: 10.1016/j.ijfoodmicro.2024.110951

Despite the general classification of L. monocytogenes strains as equally virulent by global safety authorities, molecular epidemiology reveals diverse subtypes in food, processing environments, and clinical cases. This study focuses on a highly virulent strain associated with a listeriosis outbreak in Italy in 2022, providing insights through comprehensive foodomics approaches, with a specific emphasis on quantitative proteomics. In particular, the ST155 strain of L. monocytogenes strain was subjected in vitro to growth stress conditions (NaCl 2.4 %, pH 6.2, T 12 °C), mimicking the conditions present in the frankfurter, its original source. Then, the protein expression patterns were compared with those obtained in optimal growth conditions. Through quantitative proteomic analysis and bioinformatic assessment, different proteins associated with virulence during the exponential growth phase were identified. This study unveils unique proteins specific to each environment, providing insights into how L. monocytogenes adapts to conditions that are similar to those encountered in frankfurters. This investigation contributes valuable insights into the adaptive strategies of L. monocytogenes under stressful conditions, with implications for enhancing food safety practices. •Proteomics and bioinformatics were used to characterize an ST155 strain of L. monocytogenes.•The experimental stress conditions were similar to those encountered in frankfurters.•Twenty-nine proteins were identified in cells growth under mild acid and high osmolarity level.•This finding offers valuable insights to mitigate the risk linked to L. monocytogenes contamination in food.