Objective      To determine the effect of mesna on the adhesion of

Escherichia coli

（

E.coli

） biofilm at early stage and biosynthesis of extracellular polymeric substances (EPS).       Methods      Standard colony counting

method was used to determine the effects of mesna (2 and 0.5 mg/ml) on

E.coli

adhesion at different time points. After polysaccharides and bacteria were labeled by immunofluorescent technique

the adherence and polysaccharides of

E.coli

were qualitatively observed by confocal laser scanning microscopy (CLSM). Phenol-sulfuric acid method was used to quantitate the polysaccharides content in each group. Extracellular protein content was determined by Bradford protein assay.       Results      Compared with normal saline group

the number of adhered bacteria was decreased in 2

4

6 and 8 h after intervention with mesna（

P

<

0.05）

especially in the high-dose group （

P

<

0.05）. CLSM based on FITC-ConA and PI staining showed that in 8 h after mesna intervention

the colony distribution of

E.coli

became rarefactive compared with normal saline group. The content of polysaccharides in biofilm was significantly decreased

especially in the high-dose group. Quantification of polysaccharides showed that total polysaccharides (μg )/dry weight of bacterial (mg) was 13.57±0.59 in the high-dose group and 27.77±0.77 in the low-dose group (

P

<

0.05)

significantly lower than that of normal saline group (35.73±0.44

P

<

0.05）.Quantification of extracellular protein showed that total extracellular protein (μg )/dry weight of bacterial(mg) in high-dose group（7.76±0.32）and low-dose group （17.59±0.86）were significantly lower than in normal saline group (23.31±1.36

P

<

0.05），and there was significant difference between high-dose group and low-dose group（

P

<

0.05）.       Conclusion      Mesna decreases the adhesion and EPS formation of

E. co

li significantly.