IBB-Centro de Biomedicina Molecular e Estrutural, Faculdade de Ciências e Tecnologia, Universidade do Algarve, Faro, Portugal; Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisboa, Portugal.
FEMS Microbiol Lett. 2014 May;354(2):92-101. doi: 10.1111/1574-6968.12440. Epub 2014 Apr 24.
The aim of this study was to evaluate the adaptation response of Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), and Listeria monocytogenes to the essential oil (EO), eugenol, and citral. The minimum inhibitory concentration of eugenol and citral was determined by agar dilution and microdilution. Adaptation to eugenol and citral was done by sequential exposure of the pathogens to increasing concentrations of the essential oils. The M2-A9 standard was used to determine the antibiotic susceptibility. The effect of eugenol and citral on the adherence ability was evaluated by the crystal violet assay. The impact of adaptation to eugenol on virulence was estimated using the Galleria mellonella model. No development of resistance to the components and antibiotics was observed in the adapted cells of S. aureus, MRSA, and L. monocytogenes. Eugenol and citral at subinhibitory concentration reduced the bacterial adherence. Adaptation to subinhibitory concentration of eugenol affected the virulence potential of S. aureus, MRSA, and L. monocytogenes. Eugenol and citral do not pose a risk of resistance development in a continuous mode of use. These EO components showed a high efficacy as antistaphylococcal and antilisterial biofilm agents. Adaptation at subinhibitory concentration of eugenol protected the larvae against listerial and staphylococcal infection.
本研究旨在评估金黄色葡萄球菌、耐甲氧西林金黄色葡萄球菌（MRSA）和李斯特菌对精油（EO）、丁香酚和柠檬醛的适应反应。通过琼脂稀释和微量稀释法确定丁香酚和柠檬醛的最小抑菌浓度。通过连续暴露于递增浓度的精油来实现对丁香酚和柠檬醛的适应。使用 M2-A9 标准来确定抗生素敏感性。通过结晶紫测定法评估丁香酚和柠檬醛对粘附能力的影响。通过大蜡螟模型来评估对丁香酚的适应对毒力的影响。在适应的金黄色葡萄球菌、MRSA 和李斯特菌细胞中，未观察到对这些成分和抗生素的耐药性发展。丁香酚和柠檬醛在亚抑菌浓度下降低了细菌的粘附能力。亚抑菌浓度的丁香酚适应影响了金黄色葡萄球菌、MRSA 和李斯特菌的毒力潜力。丁香酚和柠檬醛在连续使用模式下不会产生耐药性的风险。这些 EO 成分作为抗葡萄球菌和抗李斯特菌生物膜剂具有很高的功效。亚抑菌浓度的丁香酚适应可保护幼虫免受李斯特菌和葡萄球菌感染。
