The investigation of biofilm formation,alginate biosynthetic genes expression and sequence of Pseudomonas aeruginosa / 中华传染病杂志

ABSTRACT

Objective To investigate the biofilm formation,the alginate biosynthetic gene ex- pression and analyze the mucA gene sequence of mucoid Pseudomonas aeruginosa PA17 and nonmu- cold Pseudomonas aeruginosa PA01.Methods The modified plate culture method was used to estab lish the biofilm model in vitro.Semi-quantitative RT-PCR was used to determine the expression level of algD in planktonic condition and during the formation of biofilm.The mucA gene of PA17 and PA01 was amplified and the products were sequenced.Results PA17 biofilm was mature at 6th day, and PA01 biofilm was mature at 3rd day.The structures of the biofilms were both like pellicle.In planktonic condition,the algD expression of PAl7 was higher than PA01;in biofilm formation,the algD expression was maximal when the biofilm was mature.There was a 166～333 deletion mutation and 342A→G in mueA gene of PA17,the mucA gene of PA01 was the same with the sequence of Genbank.Conclusions The mucA gene mutation of PA17 was a new type,which maybe the reason for the little expression difference of algD between PA17 and PA01 during the biofilm formation than it in planctonic condition and the same structure of PA17 and PA01 biofilm.