4-羟基-2,5-二甲基-3(2H)呋喃酮对单增李斯特菌AI-2类群体感应的干扰效应

Interferce Effect of 4-Hydroxy-2,5-Dimethyl-3(2H)-Furanone on AI-2 Quorum Sensing of Listeria monocytogenes

利用群体感应抑制剂靶向干扰病源菌已成为有效控制致病性危害的突破口。本研究通过测定菌体浓度、哈氏弧菌BB170报告菌的发光值,研究不同浓度4-羟基-2,5-二甲基-3(2H)呋喃酮(DMHF)作用下单增李斯特菌(L.m)的生长与信号分子AI-2活性;通过半固体穿刺法、结晶紫法及溶血平板法检测L.m的动力、生物膜及溶血性,来评价DMHF对L.m AI-2类QS的干扰效应。结果表明,≤200μg/m L的DMHF能推迟L.m的生长,且明显抑制了L.m AI-2的活性,实验组的AI-2活性值均低于阴性对照组的40%,由此可判定DMHF是AI-2类QS的抑制剂;当DMHF浓度为100μg/mL时能明显抑制L.m的运动能力; 50、100和200μg/m L的DMHF对L.m生物膜的形成抑制率分别为29.72%、44.88%和75.27%; 200μg/m L的DMHF完全抑制溶血环的产生,本研究为利用DMHF作AI-2类QS的抑制剂提供依据。

Using of quorum-sensing inhibitors to target the quorum-sensing system（ QS） of pathogenic bacteria to reduce pathogenicity had become a breakthrough in effective control. The growth and AI-2 activities of L. m were investigated under different concentrations of DMHF by measuring the concentration of bacteria and the luminescence of reporter bacteria Vibrio harveyi BB170; The interference effects of DMHF on AI-2 system of L. m were evaluatied by detecting the dynamics,biomembranes and hemolysis test of L.m by semi-solid puncture,crystal violet and hemolytic plate method.The results showed that DMHF of ≤200 μg/mL had no effect on the growth of L. m,but significantly inhibited the activity of AI-2 system,the AI-2 activity value of the experimental groups was all lower than 40% of the negative control group,and thus it could be determined that DMHF was an inhibitor of AI-2 system; 100 μg/mL of DMHF could significantly inhibit the motor ability of L.m; The inhibitting rates of biofilm formation of L.m were 29.72%,44.88% and 75.27% at the concentration of 50,100 and 200 μg/mL of DMHF,respectively. 200 μg/mL of DMHF completely inhibited the formation of hemolytic rings. This study provided basis for the use of DMHF as an inhibitor of AI-2 system.