Laboklin GmbH & Co.KG, Bad Kissingen, Germany.
Clinic for Ruminants, Vetsuisse-Faculty, University of Bern, Bern, Switzerland.
Planta Med. 2022 Mar;88(3-04):274-281. doi: 10.1055/a-1726-9291. Epub 2022 Feb 18.
Administration of essential oils as natural plant products with antimicrobial activity might be an alternative to antibiotic treatment of bovine respiratory disease. The aim of this study was to analyse the antimicrobial activity of 11 essential oils against isolated from the respiratory tract of calves using microdilution with determination of minimum inhibitory and bactericidal concentration as well as agar disc diffusion. Additionally, antimicrobial activity against and bacteria in the clade was assessed by agar disc diffusion. Seven essential oil mixtures were also tested against all bacterial isolates. was strongly inhibited by cinnamon cassia and lemongrass oil followed by coriander, winter savory, thyme, clove, and peppermint oil in the microdilution assays. Eucalyptus, wintergreen, spruce, and star anise oil showed lower activity. Comparison of both methods revealed an underestimation of cinnamon cassia oil activity by agar disc diffusion and conflicting results for wintergreen oil in microdilution, which precipitated in broth. Cinnamon cassia, thyme, wintergreen, lemongrass, and winter savory oil all showed strong antimicrobial activity against . Bacteria in the clade were mostly inhibited by cinnamon cassia and thyme oil. isolates were more susceptible to inhibition by essential oils than isolates. Essential oil mixtures did not show stronger antibacterial activity than single essential oils. In conclusion, cinnamon cassia and lemongrass as well as coriander, winter savory, and thyme oil are promising candidates for treatment of -associated bovine respiratory infections.
作为具有抗菌活性的天然植物产品，精油的管理可能是治疗牛呼吸道疾病的抗生素治疗的替代方法。本研究的目的是分析 11 种精油对从犊牛呼吸道分离的 的抗菌活性，采用微量稀释法测定最小抑菌浓度和杀菌浓度以及琼脂扩散法。此外，还通过琼脂扩散法评估了精油对 和 属细菌的抗菌活性。还测试了 7 种精油混合物对所有细菌分离株的抗菌活性。肉桂桂皮和柠檬草油对 的抑制作用最强，其次是芫荽、冬香薄荷、百里香、丁香和薄荷油，在微量稀释试验中。桉树、水杨酸甲酯、云杉和八角茴香油的活性较低。两种方法的比较表明，琼脂扩散法低估了肉桂桂皮油的活性，而微量稀释法中水杨酸甲酯油的活性存在冲突，在肉汤中沉淀。肉桂桂皮、百里香、水杨酸甲酯、柠檬草和冬香薄荷油对 均显示出较强的抗菌活性。 属细菌主要被肉桂桂皮和百里香油抑制。 分离株比 分离株对精油抑制更敏感。精油混合物没有表现出比单一精油更强的抗菌活性。总之，肉桂桂皮和柠檬草以及芫荽、冬香薄荷和百里香油是治疗与 相关的牛呼吸道感染的有前途的候选药物。
