Insights on the microbial resistance mechanisms of listeria monocytogenes to Pulsed Electric Fields (PEF) treatments

Lytras, Fotios ; Ihsan, Muhammad Ahmed ; Psakis, Georgios ; Gatt, Ruben ; Cebrián, Guillermo (Universidad de Zaragoza) ; Raso, Javier (Universidad de Zaragoza) ; Valdramidis, Vasilis P.

Resumen: This study aimed to identify the principal mechanisms of action by which Listeria monocytogenes EGD-e responds to pulsed electric field (PEF) treatments at pH 7.0, given its recognition as a robust target microorganism and strain. Microbiologically challenged buffer samples (pH 7.0) were subjected to pulses with an electric field strength of 20 kV/cm and their transcriptional response was assessed using RNA sequencing. Our analysis revealed 119 differentially expressed genes, 51 of which were upregulated and 68 downregulated. From the 51 upregulated genes, 4 were transcription regulators (lmo1974, glnR, lmo806 and lmo0371) with the potential to influence the resistance of L. monocytogenes EGD-e. Additionally, assessment of 11 isogenic mutants at a PEF treatment (20 kV/cm, 184 kJ/kg) relative to the wild type identified the ΔyneA and ΔclpB deletion mutants as more resistant and more sensitive (p<0.05). Finally, the isogenic mutant ΔclpB was assessed against the wild type at 25 kV/cm at different total specific energies (54, 113, 135 and 160 kJ/kg) resulting in statistical difference(p<0.05) only under the highest parameter. In conclusion, transcriptomic analysis revealed that the primary mechanistic pathways of L. monocytogenes in response to PEF involve the preservation of homeostasis, energy availability, and quorum sensing. Additionally, the increased sensitivity of the ΔclpB mutant highlights a supplementary mechanism related to protein disaggregation and refolding under high-energy. These findings suggest that L. monocytogenes mounts a complex and multifaceted response to PEF treatments. These results can provide insights and support PEF treatment decontamination alone or as pretreatment in combination with other hurdles.

Idioma: Inglés

DOI: 10.1016/j.fm.2025.105014

Año: 2026

Publicado en: FOOD MICROBIOLOGY 136 (2026), 105014 [11 pp.]
ISSN: 0740-0020

Financiación: info:eu-repo/grantAgreement/EC/H2020/955431/EU/Training Network Sustainable Technologies/TRANSIT

Tipo y forma: Article (Published version)

Área (Departamento): Área Tecnología de Alimentos (Dpto. Produc.Animal Cienc.Ali.)