A comprehensive investigation of protein expression profiles in L. monocytogenes exposed to thermal abuse, mild acid, and salt stress conditions

Federica D'Onofrio; Maria Schirone; Ivanka Krasteva; Manuela Tittarelli; Luigi Iannetti; Francesco Pomilio; Marina Torresi; Antonello Paparella; Nicola D'Alterio; Mirella Luciani

doi:10.3389/fmicb.2023.1271787

A comprehensive investigation of protein expression profiles in L. monocytogenes exposed to thermal abuse, mild acid, and salt stress conditions

Front Microbiol. 2023 Oct 9:14:1271787. doi: 10.3389/fmicb.2023.1271787. eCollection 2023.

Affiliations

¹ Department of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Teramo, Italy.
² Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise "G. Caporale", Teramo, Italy.

Abstract

Preventing L. monocytogenes infection is crucial for food safety, considering its widespread presence in the environment and its association with contaminated RTE foods. The pathogen's ability to persist under adverse conditions, for example, in food processing facilities, is linked to virulence and resistance mechanisms, including biofilm formation. In this study, the protein expression patterns of two L. monocytogenes 1/2a strains, grown under environmental stressors (mild acidic pH, thermal abuse, and high concentration of NaCl), were investigated. Protein identification and prediction were performed by nLC-ESI-MS/MS and nine different bioinformatic software programs, respectively. Gene enrichment analysis was carried out by STRING v11.05. A total of 1,215 proteins were identified, of which 335 were non-cytosolic proteins and 265 were immunogenic proteins. Proteomic analysis revealed differences in protein expression between L. monocytogenes strains in stressful conditions. The two strains exhibited unique protein expression profiles linked to stress response, virulence, and pathogenesis. Studying the proteomic profiles of such microorganisms provides information about adaptation and potential treatments, highlighting their genetic diversity and demonstrating the utility of bioinformatics and proteomics for a broader analysis of pathogens.

Keywords: Listeria monocytogenes; STRING database; bioinformatic; pathogen; proteome; stressors; virulence.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. The Italian Ministry of Health funded research project IZS AM 03/17 RC (study of the phenotypic and genotypic characteristics of Listeria monocytogenes subpopulations resistant to environmental stress and to disinfectants—MSRCTE0719) covered part of the analyses that were carried out for this study.