Sweet Ryan, Booth Catherine, Gotts Kathryn, Grove Stephen F, Kroon Paul A, Webber Mark
Quadram Institute Bioscience, Norwich Research Park, Norwich NR4 7UQ, UK.
McCain Foods, 1 Tower Lane, Oakbrook Terrace, IL 60181, USA.
Microorganisms. 2023 Oct 5;11(10):2495. doi: 10.3390/microorganisms11102495.
Antimicrobial resistance is now commonly observed in bacterial isolates from multiple settings, compromising the efficacy of current antimicrobial agents. Therefore, there is an urgent requirement for efficacious novel antimicrobials to be used as therapeutics, prophylactically or as preservatives. One promising source of novel antimicrobial chemicals is phytochemicals, which are secondary metabolites produced by plants for numerous purposes, including antimicrobial defence. In this report, we compare the bioactivity of a range of phytochemical compounds, testing their ability to directly inhibit growth or to potentiate other antimicrobials against Typhimurium, , , and . We found that nine compounds displayed consistent bioactivity either as direct antimicrobials or as potentiators. Thymol at 0.5 mg/mL showed the greatest antimicrobial effect and significantly reduced the growth of all species, reducing viable cell populations by 66.8%, 43.2%, 29.5%, and 70.2% against Typhimurium, , , and , respectively. Selection of mutants with decreased susceptibility to thymol was possible for three of the pathogens, at a calculated rate of 3.77 × 10, and characterisation of Typhimurium mutants showed a low-level MDR phenotype due to over-expression of the major efflux system AcrAB-TolC. These data show that phytochemicals can have strong antimicrobial activity, but emergence of resistance should be evaluated in any further development.
目前，在多种环境中分离出的细菌菌株中普遍观察到抗菌药物耐药性，这损害了当前抗菌药物的疗效。因此，迫切需要有效的新型抗菌药物用于治疗、预防或作为防腐剂。新型抗菌化学物质的一个有前景的来源是植物化学物质，它们是植物产生的次生代谢产物，用于多种目的，包括抗菌防御。在本报告中，我们比较了一系列植物化学化合物的生物活性，测试它们直接抑制生长或增强其他抗菌药物对鼠伤寒沙门氏菌、[此处原文缺失部分细菌名称]、[此处原文缺失部分细菌名称]和[此处原文缺失部分细菌名称]的抗菌能力。我们发现九种化合物作为直接抗菌剂或增效剂表现出一致的生物活性。0.5mg/mL的百里酚显示出最大的抗菌效果，并显著降低了所有菌种的生长，对鼠伤寒沙门氏菌、[此处原文缺失部分细菌名称]、[此处原文缺失部分细菌名称]和[此处原文缺失部分细菌名称]的活菌数量分别减少了66.8%、43.2%、29.5%和70.2%。对于三种病原体，可以选择对百里酚敏感性降低的突变体，计算得出的突变率为3.77×10，对鼠伤寒沙门氏菌突变体的表征显示，由于主要外排系统AcrAB-TolC的过度表达，呈现低水平的多重耐药表型。这些数据表明，植物化学物质可以具有强大的抗菌活性，但在任何进一步的开发中都应评估耐药性的出现情况。
