摘要
【目的】探讨刺梨渣提取物对水产养殖业中主要病原菌嗜水气单胞菌的抑菌作用和机制。【方法】通过微量稀释法和平板计数法测定刺梨渣提取物对嗜水气单胞菌的最低抑菌浓度(MIC)、最小杀菌浓度(MBC),通过集群运动实验检测刺梨渣提取物对嗜水气单胞菌集群运动的影响,通过脂肪酶和蛋白酶活性实验检测刺梨渣提取物对嗜水气单胞菌脂肪酶活性和蛋白酶活性的影响,通过溶血实验测定刺梨渣提取物对嗜水气单胞菌溶血性的影响,此外通过结晶紫法检测生物膜的形成,以及荧光定量RT-PCR检测毒力和调控系统的相关基因表达情况。【结果】刺梨渣提取物对3株嗜水气单胞菌的MIC为128 mg/mL;其中嗜水气单胞菌ATCC7966的MBC为256 mg/mL,其余两株嗜水气单胞菌的MBC均>512 mg/mL。刺梨渣提取物浓度低于8 mg/mL时,不影响菌株生长;刺梨渣提取物≥4 mg/mL时,对生物膜形成、蛋白酶活性和溶血活性都具有明显的抑制作用,且呈剂量依赖抑制,但对脂肪酶的活性影响较小。荧光定量RT-PCR结果发现刺梨渣提取物能引起嗜水气单胞菌群体感应(QS)系统中luxS和ahyr基因表达显著下调;同时气溶素aerA表达量也显著下降。【结论】刺梨渣提取物能抑制嗜水气单胞菌生长及运动能力、酶活性、溶血活性、生物膜的形成以及相关毒力基因的表达,表明刺梨渣提取物是一种潜在的嗜水气单胞菌替抗物。
【Objective】This paper aims to explore the bacteriostatic effect and mechanism of Rosa rox⁃burghii Tratt pomace extract on Aeromonas hydrophila,the main pathogenic bacteria in aquaculture.【Method】The minimum inhibitory concentration(MIC)and minimum bactericidal concentration(MBC)of Rosa roxburghii Tratt pomace extract against Aeromonas hydrophila were determined by microdilution method and plate counting method,the effect of Rosa roxburghii Tratt pomace extract on Aeromonas hy⁃drophila colony movement was detected by colony movement experiment,and the effect of Rosa roxburghii Tratt pomace extract on Aeromonas hydrophila lipase and protease activity was detected by lipase and protease activity experiment.The effect of Rosa roxburghii Tratt pomace extract on the hemolysis of Aeromonas hydrophila was determined by hemolysis experiment,the formation of biofilm was detected by crystal violet method,and the virulence and gene expression of regulatory system were detected by fluorescence quantitative RT-PCR.【Result】The MIC of Rosa roxburghii Tratt pomace extract to three Aeromonas hydrophila strains was 128 mg/mL.The MBC of Aeromonas hydrophila ATCC7966 was 256 mg/mL,and the MBC of the other two Aeromonas hydrophila strains were all>512 mg/mL.When the concentration of Rosa roxburghii Tratt pomace extract was lower than 8 mg/mL,it did not affect the growth of the strain.When Rosa rox⁃burghii Tratt pomace extract≥4 mg/mL,it had obvious inhibitory effect on biofilm formation,protease activity and hemolytic activity,and showed a dose-dependent inhibition,but had little effect on lipase activity.The quantitative RT-PCR results showed that Rosa roxburghii Tratt pomace extract could significantly down-regulate the expression of luxS and ahyr genes in Aeromonas hydrophila quorum sensing(QS)system.At the same time,the expression of aerolysin aerA decreased significantly.【Conclusion】Rosa rox⁃burghii Tratt pomace extract can inhibit the growth and exercise ability,enzyme activity,hemolytic activity,biofilm formation and the expression of related virulence genes of Aeromonas hydrophila,indicating that Rosa roxburghii Tratt pomace extract is a potential substitute for Aeromonas hydrophila.
作者
曾成容
刘馨
张晨旭
毕文文
梅世慧
何广霞
张俊杰
文明
周碧君
陈江凤
姜海波
ZENG Chengrong;LIU Xin;ZHANG Chenxu;BI Wenwen;MEI Shihui;HE Guangxia;ZHANG Junjie;WEN Ming;ZHOU Bijun;CHEN Jiangfeng;JIANG Haibo(College of Animal Science,Guizhou University,Guiyang 550025,China;Guizhou Animal Biological Products Engineering Technology Research Center,Guiyang 550025,China)
出处
《四川农业大学学报》
CSCD
北大核心
2023年第3期537-545,共9页
Journal of Sichuan Agricultural University
基金
贵州省科技计划项目(黔科合支撑[2020]1Y104号、黔科合支撑[2022]一般142号)。
关键词
刺梨渣提取物
嗜水气单胞菌
抑菌
Rosa roxburghii Tratt pomace extract
Aeromonas hydrophila
bacteriostasis
