绿脓假单胞菌生物被膜形成中相关基因的表达

Expression of alginate biosynthetic genes for biofilm formation in Pseudomonas aeruginosa

目的通过检测绿脓假单胞菌生物被膜形成过程中藻酸盐合成相关基因的表达,研究藻酸盐在绿脓假单胞菌生物被膜形成过程中的作用。方法改良平板培养法建立黏液型绿脓假单胞菌PA17和非黏液型绿脓假单胞菌PAO1生物被膜模型,半定量RT-PCR测定生物被膜形成不同时间点algD、algU的表达,并进行统计学分析。结果PAO1和PA17分别于第3天和第6天形成成熟生物被膜。algD和algU均在微菌落分化为成熟生物被膜的阶段表达增高。单因素方差分析示同一菌株的相同基因在生物被膜形成过程的不同时间点表达的差异有统计学意义;两独立样本秩和检验示同一基因在不同菌株生物被膜形成过程中表达的差异无统计学意义。结论藻酸盐在绿脓假单胞菌生物被膜形成过程中微菌落分化为成熟生物被膜的阶段发挥作用,不受绿脓假单胞菌表型影响。

Objective To study the effect of alginate in the process of biofilm formation in Pseudomonas aeruginosa by detecting the expression of alginate biosynthetic gene algD and algU in nonmucoid and mucoid Pseudomonas aeruginosa strain PAO1, PA17. Methods The modified plate culture method was used to establish the biofilm model of PAO1 and PA17. Semi-quantitative RT-PCR was used to determine the expression level of algD and algU during the formation of biofilm. One-Way ANOVA and Wilcoxon rank sum test was used to identify the significance of difference. Results PAO1 and PA17 biofilm was mature at 3rd and 6th day respectively. The expression level of algD and algU was increased in the differentiation phase of microcolonies to matured biofilm. The expression difference of algD and algU in the process of biofilm formation had statistic significance, and the expression difference of these genes between PAO1 and PA17 had no statistic significance. Conclusion Alginate played a role in the differentiation phase of microcolonies to matured biofilm, and the effect was not influenced by the phenotype of Pseudomonas aeruginosa.