{"title":"Exploring the mechanisms of Staphylococcus aureus pulsed electric fields resistance acquisition after exposure to heat and alkaline shocks","authors":"Laura Nadal, Guillermo Cebrián, Pilar Mañas","doi":"10.1016/j.ifset.2024.103707","DOIUrl":null,"url":null,"abstract":"<div><p>This study aimed to acquire a deeper knowledge of the mechanisms of PEF resistance development after the exposure of <em>Staphylococcus aureus</em> 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 (<em>p</em> < 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 <em>de novo</em> 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.</p></div><div><h3>Industrial relevance</h3><p>This work contributed to a deeper understanding of the mechanisms leading to the development of PEF resistance, which is essential for PEF process optimization and for the design of PEF-based combined processes for food decontamination or pasteurization.</p></div>","PeriodicalId":329,"journal":{"name":"Innovative Food Science & Emerging Technologies","volume":null,"pages":null},"PeriodicalIF":6.3000,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1466856424001462/pdfft?md5=0c90fed2297cb06c2fc9987c3e68e4ad&pid=1-s2.0-S1466856424001462-main.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Innovative Food Science & Emerging Technologies","FirstCategoryId":"97","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1466856424001462","RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"FOOD SCIENCE & TECHNOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
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.
Industrial relevance
This work contributed to a deeper understanding of the mechanisms leading to the development of PEF resistance, which is essential for PEF process optimization and for the design of PEF-based combined processes for food decontamination or pasteurization.
期刊介绍:
Innovative Food Science and Emerging Technologies (IFSET) aims to provide the highest quality original contributions and few, mainly upon invitation, reviews on and highly innovative developments in food science and emerging food process technologies. The significance of the results either for the science community or for industrial R&D groups must be specified. Papers submitted must be of highest scientific quality and only those advancing current scientific knowledge and understanding or with technical relevance will be considered.