摘要
为系统评估茶黄素对奇异变形杆菌(Proteus mirabilis)的抑制作用,采用微量稀释法测定茶黄素的最低抑菌浓度(MIC)和最低杀菌浓度(MBC),利用生长曲线分析、结晶紫染色法、生化反应检测及实时定量PCR(qPCR)等方法,探讨其对细菌生长、迁徙、生物膜形成、结晶生成及毒力基因表达的影响。研究结果表明:茶黄素能够显著抑制细菌生长(188μg·mL^(-1)时几乎完全抑制,375μg·mL^(-1)时完全杀菌),降低脲酶与溶血素活性(脲酶抑制率>50%,溶血素活性近乎完全抑制),并抑制生物膜形成(OD490显著下降,P<0.05)。茶黄素处理组培养液中Ca^(2+)和Mg^(2+)离子浓度显著降低;qPCR检测显示,茶黄素可显著下调ureR、hpmA、flhD和flhB等关键毒力基因的mRNA表达。
To systematically evaluate the inhibitory effect of theaflavins on Proteus mirabilis,the minimum inhibitory concentration(MIC)and minimum bactericidal concentration(MBC)were determined using the microdilution method.Growth curve analysis,crystal violet staining,biochemical assays,and quantitative real-time PCR(qPCR)were employed to investigate their effects on bacterial growth,motility,biofilm formation,crystal generation,and virulence gene expression.The results showed that theaflavins significantly inhibited bacterial growth(almost completely inhibited at 188μg·mL^(-1)and completely bactericidal at 375μg·mL^(-1)),reduced urease and hemolysin activities(urease inhibition rate>50%,hemolysin activity nearly completely suppressed),and inhibited biofilm formation(OD490 significantly decreased,P<0.05).In the theaflavin-treated group,the concentrations of Ca^(2+)and Mg^(2+)ions in the culture supernatant were significantly reduced.qPCR analysis revealed that theaflavins markedly downregulated the mRNA expression of key virulence genes,including ureR,hpmA,flhD,and flhB.
作者
陈慧玲
薛志春
刘芳
陈煌婷
CHEN Hui-ling;XUE Zhi-chun;LIU Fang;CHEN Huang-ting(College of Marine Sciences,Ningde Normal University,Ningde,Fujian 352100,China;Engineering Research Center of Mindong Aquatic Product Deep-Processing,Ningde,Fujian 352100,China;Ningde Municipal Hospital Affiliated to Ningde Normal University,Ningde,Fujian 352100,China)
出处
《宁德师范学院学报(自然科学版)》
2025年第3期285-291,共7页
Journal of Ningde Normal University(Natural Science)
基金
宁德师范学院校级专项资助计划科研项目(2023ZX218、2023ZX708)。
关键词
茶黄素
奇异变形杆菌
抗菌作用
生物膜
毒力基因
theaflavin
Proteus mirabilis
antibacterial activity
biofilm
virulence genes
