8味中草药水提物对马红球菌的体外抑菌和杀菌效果研究

目的] 筛选对马红球菌（Rhodococcus equi,R. equi）具有抑菌和杀菌效果的中草药。方法] 选择黄连、黄芩、大青叶、鱼腥草、黄柏、连翘、金银花及板蓝根共8味中草药制备单味水提物,采用微量肉汤稀释法及平板涂布法测定中草药水提物对R. equi参考菌株103S及临床分离株的最小抑菌浓度和最小杀菌浓度。结果] 不同中草药水提物对R. equi的抑菌及杀菌效果不同,其中,黄连、黄柏和连翘单独用药杀菌及抑菌效果显著（P<0.05）强于其他中草药水提物;黄连、黄柏和连翘不同组合联合用药对R. equi的抑菌及杀菌效果均优于单独用药,其中,“黄连+连翘”联用后药效呈相加作用。结论] 黄连等中草药对R. equi表现出抑菌及杀菌效果,且联合用药效果优于单独用药,提示这些中草药制剂有望作为抗R. equi乃至其他耐药病原微生物感染的有效治疗药物。

In Vitro Antibacterial and Bactericidal Actions of Aqueous Extracts from 8 Kinds of Chinese Medicinal Herbs against Rhodococcus equi

Objective] This study was conducted to screen the Chinese medicinal herbs that have antibacterial and bactericidal actions against Rhodococcus equi （R. equi）. Method] The aqueous extracts from each of the 8 kinds of Chinese medicinal herbs including Coptis chinensis, Scutellaria baicalensis, Ficus hirta, Houttuynia cordata, Platycladus orientalis, Forsythia suspensa, Lonicera japonica and Isatis tinctoria were prepared, respectively. The minimum inhibitory concentration （MIC） and minimum bactericidal concentration （MBC） of the aqueous extracts from the Chinese medicinal herbs against reference strain 103S and clinical isolates of R. equi were determined using broth micro-dilution method and spread-plate method, respectively. Result] The antibacterial and bactericidal actions of the aqueous extracts from different Chinese medicinal herbs against R. equi varied, and Coptis chinensis, Platycladus orientalis and Forsythia suspensa had significantly （P<0.05） better performance than the others. The use of different combinations of the aqueous extracts from Coptis chinensis, Platycladus orientalis and Forsythia suspensa exhibited stronger antibacterial and bactericidal actions against R. equi than their single use. The combinative use of Coptis chinensis and Forsythia suspensa showed an additive effect. Conclusion] The Chinese medicinal herbs such as Coptis chinensis show antibacterial and bactericidal actions against R. equi, and the combinative use of these herbs have better performance than their single use, suggesting that these herbs have potential to be effective therapeutic drugs against infections caused by R. equi and even by other antimicrobial-resistant pathogens.