The goal of this study was to evaluate the development of Salmonella enterica subsp. enterica serovar Typhimurium resistance against Pulsed Electric Fields (PEF) and High Hydrostatic Pressure (HHP), and to study the possible virulence changes of the resistant subpopulations using Caenorhabditis elegans. Results showed that S. Typhimurium became resistant to both non-thermal technologies after four consecutive treatments. Survival probability of the worms (C. elegans) increased significantly when they were fed with S. Typhimurium treated by PEF four consecutive times in comparison with the other two subpopulations, untreated and treated once. For HHP, results indicated that up to percentile 50%, the survival probability of worms fed with treated microorganisms (once and four times) was greater than that of worms fed with untreated ones. Also, the C. elegans egg-laying pattern was modified and there were significant differences in the number of eggs laid in the first two days among the three subpopulations studied. Consequently, although S. Typhimurium develops microbial resistance against PEF or HHP treatments, when it is applied repeatedly, its virulence against C. elegans appears to decrease.

Industrial relevance

Among the non-thermal technologies, Pulsed Electric Fields and High Hydrostatic Pressure have a great potential. Nevertheless, it is necessary to validate them from a safety point of view because of the huge amount of damaged cells that can be obtained if sublethal treatments are applied. These studies have industrial relevance in food safety ensuring proper processing when using these non-thermal technologies.

中文翻译：

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高静水压和脉冲电场处理的肠沙门氏菌鼠伤寒杆菌的耐药性变化及以秀丽隐杆线虫为试验生物评价毒力变化。

这项研究的目的是评估肠炎沙门氏菌亚种的发展。鼠血清型鼠伤寒杆菌对脉冲电场（PEF）和高静水压力（HHP）的抵抗力，并利用秀丽隐杆线虫研究耐药性亚群可能的毒力变化。结果表明，S。在连续四次治疗后，鼠伤寒对两种非热技术都产生了抵抗力。喂食S的线虫（C. elegans）的存活率显着增加。。与其他两个亚群相比，PEF连续处理了四次鼠伤寒，未经处理和处理过一次。对于HHP，结果表明高达50％的百分数，饲喂经过处理的微生物的蠕虫的存活概率（一次和四次）要大于未经处理的微生物的蠕虫的存活概率。此外，秀丽隐杆线虫的卵子产卵模式得到了改变，在所研究的三个亚群中，前两天卵子的产卵数存在显着差异。因此，虽然小号。鼠伤寒会产生对PEF或HHP处理的微生物抗性，如果反复使用，其对秀丽隐杆线虫的毒力似乎会降低。

行业相关性

在非热技术中，脉冲电场和高静水压力具有巨大的潜力。然而，由于使用亚致死性处理会获得大量受损细胞，因此有必要从安全角度进行验证。这些研究与食品安全在工业上相关，可确保在使用这些非热技术时进行适当的加工。