中文摘要：

目的：探讨PA17和PAO1生物膜形成过程中播种型扩散发生的相关机制。方法：SYTO9/PI双染色后,在激光共聚焦显微镜下观察1、3、5、7、9、11d时PAO1及PA17生物膜形成的情况,real-time RT-PCR检测不同时间点PAO1及PA17的algR的表达。结果：PAO1 3d时形成生物膜,但PA17此时尚未形成生物膜。PAO1在第11天出现播种型扩散,PA17于7d时出现播种型扩散的现象。浮游状态下PA17的algR基因表达高于PAO1,随后两株菌的algR基因表达量逐渐降低,5d时出现升高,PA17 7d时表达量最高,PAO1于11d时algR表达量最高。结论：PAO1的播种型扩散晚于PA17,AlgR与播种型扩散的发生有关。

英文摘要：

Objective：To explore the mechanism of seeding dispersal in Pseudomonas aeruginosa containing mucus-type PA 17 with the new mucA gene mutation and non-mucoid PAO1 with wild-type mucA gene.Methods：The bacteria were cultured to establish a biofilm model,the 1,3,5,7,9 and 11 days old biofilms were observed by Confocal scanning laser microscopy with SYTO9/PI viability staining.Real-time fluorescent quantitative reverse transcription-polymerase chain reaction（RT-PCR） was used to detect the expression level of algR gene in PAO1 strain and PA17 strain at different time.Results：Mature biofilms were observed at 3rd day in PAO1,while PA17 was not form biofilm still.PAO1 exhibited ＇seeding dispersal＇ at 11th day,and PA17 at 7th day.The expression level of algR gene was higher in PA17 than that in PAO1 at planktonic mode,and then the expression level decreased both in PAO1 and PA17,but it increased at 5th day,and highest at 11th day and 7th day respectively in PAO1 and PA17.Conclusion：The phenomenon of ＂seeding dispersal＂ was earlier in PA17 than in PAO1 which was associated with algR gene.