Exploring the mechanisms of Staphylococcus aureus pulsed electric fields resistance acquisition after exposure to heat and alkaline shocks

Nadal, Laura (Universidad de Zaragoza) ; Cebrián, Guillermo (Universidad de Zaragoza) ; Mañas, Pilar (Universidad de Zaragoza)

Resumen: This study aimed to acquire a deeper knowledge of the mechanisms of PEF resistance development after the exposure of Staphylococcus aureus to sublethal alkaline and heat shocks, with a particular focus on the modifications of cell envelope properties and their impact on electroporation and its reversion. Both shocks significantly (p < 0.05) increased the surface negative charge but they barely affected surface hydrophobicity or membrane fluidity. This resulted in an increased electroporation threshold (≈ 2 kV/cm) for alkaline-shocked but not for heat-shocked cells. Heat and alkaline shock-dependent development of PEF resistance did not require de novo RNA, protein, or lipid synthesis. Addition of nisin (100 UI/mL) to the treatment medium not only counteracted the protective effect of sublethal shocks against PEF, but even increased the lethality of PEF treatments (up to 8.9-fold increase in Log cycles of inactivation) against heat-shocked and alkaline-shocked cells.

Idioma: Inglés

DOI: 10.1016/j.ifset.2024.103707

Año: 2024

Publicado en: INNOVATIVE FOOD SCIENCE & EMERGING TECHNOLOGIES 95 (2024), 103707 [9 pp.]
ISSN: 1466-8564

Financiación: info:eu-repo/grantAgreement/ES/DGA/A03-23R
Financiación: info:eu-repo/grantAgreement/ES/MEFPD/FPU18-04898
Financiación: info:eu-repo/grantAgreement/ES/UZ/JIUZ-2017-CIE-01

Tipo y forma: Artículo (Versión definitiva)

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