桦褐孔菌发酵鸭跖草提取物对铜绿假单胞菌群体感应系统的影响

【背景】群体感应在铜绿假单胞菌感染中常引起对抗生素的耐药性,因此迫切需要寻找新型抑制剂。【目的】研究桦褐孔菌发酵鸭跖草提取物(fermented Commelina communis extract,FCC)对铜绿假单胞菌(Pseudomonas aeruginosa,PA)群体感应系统的影响及其原因。【方法】采用微量稀释法测定FCC对PA的最小抑菌浓度(minimal inhibitory concentration,MIC),通过微量法测定FCC对生物膜形成、以及毒力因子(绿脓素、LasA蛋白酶及鼠李糖脂)合成的影响,利用高效液相色谱(high performance liquidchromatography,HPLC)法分析发酵前后化学物质的变化,采用福林酚(Folinand Ciocalteu's phenolreagent,Folin-Ciocalteu)法测量FCC和未发酵鸭跖草提取物(unfermented Commelina communis extract,UCC)的总酚含量。【结果】发酵前后提取物的MIC分别为16 g/L和64 g/L,FCC抑制了生物膜的形成,降低了毒力因子的产生,发酵提取物的化学组分在发酵过程中产生了很大的变化,发酵后提取物总酚含量相较于未发酵增加了219.97%。【结论】桦褐孔菌固体发酵具有增强鸭跖草提取物抗PA群体感应的作用,通过抑制群体感应系统产生抑菌作用。

Effects of Commelina communis extract fermented by Inonotus obliquus on quorum sensing system of Pseudomonas aeruginosa

Background] Quorum sensing often causes resistance to antibiotics in Pseudomonas aeruginosa infection, so it is urgent to find new inhibitors. Objective] To investigate the mechanism of Fermentation extract by Inonotus obliquus in Commelina communis against Pseudomonas aeruginosa targeting quorum sensing system and the reasons. Methods] The microdilution method was adopted to determine the minimal inhibitory concentration of fermentation extract for PA; The effects of fermentation extract on Biofilm formation, pyocyanin production, LasA proteases activity and productionof rhamnolipid were detected by microtitration; Analyze chemical compounds changed by HPLC, The Folin-Ciocalteu method was used to detect Total phenolic content of FCC and UCC. Results] The MIC of Pseudomonas aeruginosa for FCC and UCC was 16 g/L and 64 g/L, respectively; FCC could significantly inhibit the activity of Biofilm formation and Virulence factors of bacteria; The use of fermentation as separate processes could change the levels of many compounds in fermentation extract. The total phenol content of the fermented extract increased by 219.97% compared with the unfermented extract. Conclusion] The results of present study suggested that FCC enhance inhibited Pseudomonas aeruginosa quorum sensing system function and plays a role bacteriostatic action by anti-quorum sensing activity.