群体感应系统对大鼠腹腔铜绿假单胞菌生物被膜感染的影响

Impact of quorum sensing system on intraperitoneal implant Pseudomonas aeruginosa biofilm infection in rats

目的探讨群体感应(quorum sensing,QS)系统对腹腔植入物铜绿假单胞菌(PA)生物被膜(biofim,BF)感染致病性的影响。方法以输液管为载体,PAO1、PAO1-JP2为实验菌株,建立大鼠腹腔移植物PA BF感染动物模型,采用连续稀释法进行载体表面活菌计数。扫描电镜(SEM)观察载体BF的形态变化。结果组织病理学可见PAO1组炎性反应较PAO1-JP2组更严重。SEM观察发现PAO1组载体表面细菌黏附和形成的BF较PAO1-JP2组稠厚。载体表面BF内活菌计数PAO1组显著高于PAO1-JP2组(P<0.01),并且在第7天后有增多趋势(P<0.05)。结论在体内移植物PA感染过程中,BF形成及感染的程度受QS系统调节,其在PA BF相关感染中起着重要作用。

Objective To evaluate the impact of the quorum sensing（QS） system on intraperitoneal implant Pseudomonas aeruginosa（PA） biofilm（BF）infection.Methods The model of PAO1 and PAO1-JP2 intraperitoneal implant BF infection in rats was established,respectively.The BF morphological changes were observed on the carrier surface by scanning electron microscope（SEM）.The viable PA within BF was counted with the continuous dilution method.Results The inflammation response of the local peritoneal tissue in the PAO1 group was more serious than that in the PAO1-JP2 group.On 3,7,14 d,the bacterial adhesion and the biofilm formation of the PAO1 group on the carrier surface was more thicker than those in the PAO1-JP2 group on SEM.The viable colony on the carrier surface count of the PAO1 group was significantly higher than that of the PAO1-JP2 group（P0.01）,while the cleared colonies was slower than the PAO1-JP2,further more,had a growing trend from 7 d（P0.05）.Conclusion During intraperitoneal implant PA infection,the BF formation and the infection severity are regulated by the QS system,which plays an important role in PA BF related infection.