Natural antimicrobial synergy against food spoilage and pathogenic bacteria

大多数天然抗菌剂在食品中的使用历史悠久，通常用于满足文化偏好或对颜色、风味甚至保质期的期望，在无法获得适当冷藏的情况下。拟议的工作将检查来自植物源食品的一些更有效的材料中的活性成分，以确定这些物质如何抑制和杀死腐败细菌和致病菌。一旦了解了天然抗菌药物的作用机制，就可以利用药物组合同时在多个靶点抑制细菌，从而优化抗菌活性。拟议的工作将侧重于从香料精油中提取的几种天然抗菌剂，这些抗菌剂的效力通常与传统药物相当。这些将包括异硫氰酸烯丙酯（AIT），肉桂醛，丁香酚和香芹酚。该实验室先前的研究表明，丁香酚和香芹酚对肉桂醛的作用存在差异。AIT的主要抗菌靶点可能进一步不同。肉桂醛对细胞分裂具有独特的促进纤维形成的作用，而AIT可能抑制DNA合成。这些问题将在拟议的工作中进行探讨，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。根据这些药物抗菌作用的已知差异，将对具有潜在不同作用机制的药物组合进行评估，以评估其增加对单一药物的敏感性或克服耐药性的能力。这项工作的新颖性来自于它使用了关于抗菌作用模式差异的最新信息来测试微生物控制可以通过加性或协同效应实现的假设。此外，测试抗菌素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，关注的病原体在这些药物的挑战下产生耐药性的可能性很小。根据这项工作，预计可以更有效地利用天然抗菌剂，以减少食源性疾病和食物过早变质的风险。

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.