鱼腥草素钠对铜绿假单胞菌群感效应系统影响的研究

Effect of sodium houttuyfonate on quorum sensing system of Pseudomonas aeruginosa

目的研究鱼腥草素钠(SH)对铜绿假单胞菌(Pseudomonas aeruginosa,PA)群感效应系统的影响,以期探明SH抗PA的作用机制。方法微量稀释法测定SH和阿奇霉素(AZM)对PA的最小抑菌浓度(MIC);紫外分光光度法测定SH对PA LasA蛋白酶活性和绿脓菌素生成的影响;平板法观察PA的形态;半定量PCR法和实时荧光定量PCR(q RT-PCR)法检测群感效应相关的基因lasI、rhlI、lasR、rhlR、phzM、pqsA、pslA、lasA、las B、toxA表达量的变化。结果 SH和AZM对PA的MIC分别为512μg/m L和64μg/m L;紫外分光光度法结果显示SH能够抑制LasA蛋白酶的活性和绿脓菌素的合成;SH能够显著影响PA的形态;半定量PCR和q RT-PCR结果显示在SH作用下lasI、rhlI、lasR、lasA、pslA、phz M基因表达显著发生变化。结论 SH具有抗PA群感效应属性,通过抑制PA的群感效应系统发挥抗菌作用。

Objective To investigate the mechanism of sodium houttuyfonate（SH） against Pseudomonas aeruginosa（PA） targeting quorum sensing system. Methods The microdilution method was adopted to determine the minimal inhibitory concentration（MIC） of SH and azithromycin（AZM） for PA; The effects of SH on Las A proteases activity and pyocyanin production were detected by UV spectrophotometry; The semi-quantitative PCR and q RT-PCR were used to detect the expression changes of quorum sensing regulatory genes（lasI, rhlI, lasR, rhlR, phzM, pqsA, pslA, lasA, lasB, and toxA）. Results The MIC of P. aeruginosa for SH and AZM was 512 μg/m L and 64 μg/m L, respectively; SH could significantly inhibit the activity of Las A proteases, and pyocyanin of bacteria; The morphology of P. aeruginosa was observed by agar plates; Furthermore, semi-quantitative PCR and q RT-PCR results indicated that the expression of lasI, rhlI, lasR, lasA, pslA, and phzM was significantly impact by SH. Conclusion The results of present study suggest that SH possesses anti-quorum sensing properties and plays a role against infection by anti-quorum sensing activity.