禽致病性大肠杆菌生物被膜的形成及其影响因素

The biofilm formation of avian pathogenic Escherichia coli in vitro

为确定影响细菌生物被膜(BF)的形成条件,本研究采用BF体外定性观察和定量粘附性检测两种方法对1株野生禽致病性大肠杆菌(E.coli)在不同环境(培养时间、培养基类型、引导载体类型、营养条件)下产生BF的差异进行了研究。结果显示野生禽致病性E.coli其宿主体外BF最适形成条件是培养时间为48h,培养基为5%TSB、引导载体为平底96孔聚苯乙烯微孔板(美国Corning Costar)。其生长周期为8h时开始起始粘附、24h形成若干微菌落、36h微菌落粘连、48h形成完整的BF、72h细菌脱落开始下一轮的BF生长。糖分和适量的无机盐都可以在一定程度上促进BF的形成和被膜内细菌的粘附性提高。该研究表明禽致病性E.coliBF的形成周期,并为抑制其形成提供了实验依据。

To investigate the biofilm formation of the avian pathogenic Escherichia coli by establishing a in vitro qualitative model and quantitative adhesion test. A wild type pathogenic E. coli was cultivated in flat-bottom 96-well polystyrene microplate substratum with 5% TSB medium under different cultivation time,mediums,substratums and nutrients. Biofilm was well developed at 37 ℃ after 48 hours cultivation. The formation period included an initial adhesion to the surface at 8 hours,the development of micro-colonies at 24 hours,the conglutination of micro-colonies at 36 hours,the mature of biofilm at 48 hours,and the desquamation from the substratum,and followed by a new formation circulation. It was also showed that sugars,sodium chloride and Mg2＋ would enhance the development of the biofilm and the adherent ability of the bacteria. The results may provide a basis for clinical therapy to the bacterial biofilm disease.