Natural antimicrobial synergy against food spoilage and pathogenic bacteria

大多数天然存在的抗菌剂在食品中的使用历史很长，通常用于满足文化偏好或对颜色，风味，甚至在无法获得适当冷藏的情况下的保质期的期望。拟议的工作将检查一些来自植物源食品的更有效材料中的活性成分，以确定这些试剂如何抑制和杀死腐败和致病菌。 一旦天然抗微生物剂作用的机制是已知的，试剂的组合可以用于同时抑制细菌在多个目标，优化抗微生物活性。 拟议的工作将集中在几个天然抗菌剂从香料精油已知的效果往往与传统的代理商的效力。 这些将包括异硫氰酸烯丙酯（AIT）、肉桂醛、丁香酚和香芹酚。 本实验室以前的工作表明，肉桂醛与丁香酚和香芹酚的作用不同。AIT的主要抗微生物靶标可能进一步不同。 肉桂醛对细胞分裂有独特的作用，导致细丝形成，而AIT可能抑制DNA合成。这些问题将在拟议的工作中探讨，注意到主要的抑制作用往往最终转化为细胞膜完整性的丧失。 基于这些药物的抗菌作用的已知差异，将评价具有潜在不同作用机制的药物组合引起敏感性增加或克服对单一药物耐药性的能力。 这项工作的新奇之处在于它利用了关于抗菌作用模式差异的最新信息，以检验微生物控制可以通过加和或协同效应实现的假设。 此外，受试抗菌剂的一个不太为人所知的特征是，根据我们目前对其作用机制的了解，关注的病原体在应对这些药物的挑战时产生耐药性的可能性很小。从这项工作中，预计可以更有效地利用天然存在的抗菌剂，以减少食源性疾病和过早食品腐败的风险。

Most naturally occurring antimicrobials have a long history of use in foods, often being used to satisfy cultural preferences or expectations regarding colour, flavour, and even shelf-life where access to suitable refrigeration has been unavailable. Work proposed will examine active components in some of the more potent materials from foods of plant origin to determine how these agents work to inhibit and kill spoilage and pathogenic bacteria. Once the mechanism of natural antimicrobial agent action is known, combinations of agents can be used to simultaneously inhibit bacteria at multiple targets, optimizing antimicrobial activity. Proposed work will focus on several natural antimicrobials from spice essential oils known to have effects often comparable in potency with conventional agents. These will include allyl isothiocyanate (AIT), cinnamaldehyde, eugenol and carvacrol. Previous work from this laboratory has shown differences in the action of cinnamaldehyde from eugenol and carvacrol. The primary antimicrobial target of AIT may further differ. Cinnamaldehyde has unique effects on cell division causing filament formation, whereas AIT may inhibit DNA synthesis. These issues will be explored in the proposed work, being mindful that principal inhibitory effects often translate ultimately into loss of cell membrane integrity. On the basis of known differences in antimicrobial action of these agents, combinations of those with potentially different mechanisms of action will be evaluated for their ability to cause increased sensitivity or overcome resistance to single agents. Novelty in the work derives from its use of recent information on differences in modes of antimicrobial action to test the hypothesis that microbial control can be achieved through additive or synergistic effects. Further, a less well recognized characteristic of the test antimicrobials is that based on what we currently know about their mechanism(s) of action, there is little likelihood that pathogens of concern will develop resistance in response to challenge by these agents. From this work it is expected that more effective use can be made of naturally occurring antimicrobials to reduce risk of foodborne illness and premature food spoilage.