植物来源的醛是精油的成分,具有广谱抗微生物活性并杀死微生物而不促进抗性。在我们之前的研究中,我们通过可降解缩醛(PANDAs)将八角茴香中的对茴香醛掺入到称为前抗菌网络的聚合物网络中,并将其用作新型药物递送平台.PANDAs在pH和湿度变化时释放对茴香醛,并控制了耐多药病原体铜绿假单胞菌PAO1的生长。在这项研究中,我们通过产生10,000个PAO1转座子突变体鉴定了对茴香醛靶向的细胞通路,并筛选了它们对对茴香醛的超敏反应.为了提高对茴香醛的抗菌效果,我们将其与表没食子儿茶素没食子酸酯(EGCG)结合使用,一种来自绿茶的多酚,并证明它与对茴香醛协同作用杀死铜绿假单胞菌。然后我们使用转录组测序来描述铜绿假单胞菌对对茴香醛的反应,EGCG,和他们的组合。对茴香醛的暴露改变了与细胞包膜修饰有关的基因的表达,膜运输,药物外排,能量代谢,钼辅因子生物合成,和应激反应。我们还证明了EGCG的添加逆转了许多对茴香醛的应对作用并诱导了氧化应激。我们的结果提供了对茴香醛的抗菌活性及其与EGCG的相互作用的见解,并可能有助于合理鉴定植物代谢产物的新协同作用组合。我们的研究还证实了硫醇-烯聚合物平台用于持续有效地递送疏水性和挥发性抗微生物化合物的实用性。IMPORTANCE精油(EO)是植物衍生产品,长期以来一直被用于药物中的抗菌活性,农业,和食物保存。EO代表了一个有希望的替代传统抗生素由于其广泛的抗菌活性,对人类共生细菌毒性低,和杀死微生物而不促进抗性的能力。尽管对EO的生物活性的理解取得了进展,我们对他们行动方式的许多方面的理解仍然没有定论。这项工作的总体目标是通过研究抗微生物植物醛与机会性人类病原体铜绿假单胞菌之间的分子相互作用来解决这些空白。这项研究的结果鉴定了与抗微生物植物醛反应有关的微生物基因和相关途径,并提供了对控制精油中各个成分的协同作用的分子机制的见解。
Plant-derived aldehydes are constituents of essential oils that possess broad-spectrum antimicrobial activity and kill microorganisms without promoting resistance. In our previous study, we incorporated p-anisaldehyde from star anise into a polymer network called proantimicrobial networks via degradable acetals (PANDAs) and used it as a novel drug delivery platform. PANDAs released p-anisaldehyde upon a change in pH and humidity and controlled the growth of the multidrug-resistant pathogen Pseudomonas aeruginosa PAO1. In this study, we identified the cellular pathways targeted by p-anisaldehyde by generating 10,000 transposon mutants of PAO1 and screened them for hypersensitivity to p-anisaldehyde. To improve the antimicrobial efficacy of p-anisaldehyde, we combined it with epigallocatechin gallate (EGCG), a polyphenol from green tea, and demonstrated that it acts synergistically with p-anisaldehyde in killing P. aeruginosa We then used transcriptome sequencing to profile the responses of P. aeruginosa to p-anisaldehyde, EGCG, and their combination. The exposure to p-anisaldehyde altered the expression of genes involved in modification of the cell envelope, membrane transport, drug efflux, energy metabolism, molybdenum cofactor biosynthesis, and the stress response. We also demonstrate that the addition of EGCG reversed many p-anisaldehyde-coping effects and induced oxidative stress. Our results provide insight into the antimicrobial activity of p-anisaldehyde and its interactions with EGCG and may aid in the rational identification of new synergistically acting combinations of plant metabolites. Our study also confirms the utility of the thiol-ene polymer platform for the sustained and effective delivery of hydrophobic and volatile antimicrobial compounds.IMPORTANCE Essential oils (EOs) are plant-derived products that have long been exploited for their antimicrobial activities in medicine, agriculture, and food preservation. EOs represent a promising alternative to conventional antibiotics due to their broad-range antimicrobial activity, low toxicity to human commensal bacteria, and capacity to kill microorganisms without promoting resistance. Despite the progress in the understanding of the biological activity of EOs, our understanding of many aspects of their mode of action remains inconclusive. The overarching aim of this work was to address these gaps by studying the molecular interactions between an antimicrobial plant aldehyde and the opportunistic human pathogen Pseudomonas aeruginosa The results of this study identify the microbial genes and associated pathways involved in the response to antimicrobial phytoaldehydes and provide insights into the molecular mechanisms governing the synergistic effects of individual constituents within essential oils.