壳聚糖对大肠埃希菌生物被膜形成的作用

Effect of Chitosan on Escherichia coli Biofilm Formation

目的探讨壳聚糖对大肠埃希菌生物被膜形成的作用。方法以空白导管(对照组)、包被分子量5000、30万、100万壳聚糖的导管为载体,构建形成7d的大肠埃希菌生物被膜,并依次设为第1、2、3、4实验组;然后细菌计数、生物被膜定量、扫描电镜(SEM)观察。结果第1、2、3和4组的细菌计数依次是2.29×107CFU/ml、1.19×107CFU/ml、1.45、1.99×107CFU/ml;吸光度为0.137、0.050、0.080和0.135;扫描电镜下,第1组的细菌密集、均匀,细胞壁较光滑、菌体规则;第2、3组的细菌少,呈聚集状,菌体有凹陷、扭曲现象;第4组细菌密集。结论分子量5000和30万的壳聚糖对形成7d的大肠埃希菌生物被膜有抑制作用,分子量5000的壳聚糖作用更强;分子量100万壳聚糖没有抑制作用。

OBJECTIVE To investigate effect of chitosan on Escherichia coli biofilm formation. METHODS E. coli biofilms of 7 days were established adopting the blank tubes,tubes coated chitosans with molecular weigh 5000,300000,1000000 respectively,which arranged as the first ,second,third,fourth group.Each group was carried out on bacterial counting,biofilm ration and observation under SEM respectively. RESULTS The bacterial quantity of group 1,2,3,4 were 2.29×10^7 CFU/ml,1.19,1.45,1.99×10^7 CFU/ml respectively. The absorbency value of group 1,2,3,4 were 0.137,0.050,0.080,0.135 respectively. Under the circumstance of SEM,there were uniform and intensive bacteria on photograph of group1. The bacterias had smooth cell wall,the regular body. There were few bacteria showing gathering state on photograph of group 2 and 3. The bacteria had sinking or scarred body. CONCLUSIONS Both chitosan with molecular weigh 5000 and 300,000 could inhibite the formation of E. coli biofilm of 7 days. The chitosan with 5000 have better efftection,but the chitosan with molecular weigh 1,000,000 can not inhibit.