干酪乳杆菌对产肠毒素大肠杆菌粘附Caco-2细胞抑制作用的研究

Inhibitory effect of Lactobacillus casei on adhesion of enterotoxigenic Escherichia coli to Caco-2 cells

为研究干酪乳杆菌(L.casei)对人结肠癌Caco-2细胞的粘附特点及抑制产肠毒素大肠杆菌K88(ETEC K88)粘附Caco-2细胞的能力,本研究将不同浓度的L.casei和ETEC K88与分化完全的Caco-2细胞共培养2 h和4 h后,采用平板计数法和革兰染色法计算每个细胞上粘附菌的个数,评价L.casei的粘附特点及其抑制ETEC K88对Caco-2细胞的粘附能力,并分析其影响因素。结果表明,L.casei与ETEC K88均可以粘附至Caco-2细胞表面,并且随菌液浓度的升高和培养时间的延长,粘附的数量显著增加(p<0.05)。L.casei浓度越高,抑制ETEC K88粘附至细胞表面的能力越强,并与菌液添加顺序有关,但培养时间对其影响不显著(p>0.05)。本研究为L.casei抑菌作用机制的研究提供了实验依据。

The aim of the experiment was to study the adhesion characteristics of Lactobacillus casei to Caco-2 cells, and its inhibitions on adhesion of enterotoxigenic Escherichia coli（ETEC） K88 to Caco-2 cell. The number of bacteria adhered to each cell was calculated after different concentrations of L.casei and ETEC K88 were added to Caco-2 cells simultaneously for 2 hours and 4 hours, respectively. The results indicated that L.casei and ETEC K88 was able to adhere to Caco-2 cells, with the increase of concentrations and incubation time of bacterias, the number of bacterias adhered to each cell increased significantly（ p0.05）.Moreover, the higher the concentrations of L.casei, the stronger the inhibiting ability on ETEC K88 adhered to the cells, which also associated with the adding order of bacteria. However, the influence of incubation time was not significant（ p0.05）. In conclusion, adhesive capacity of L.casei to Caco-2 cells depends on the concentration and incubation time, L.casei had the ability to inhibit the adhesion of pathogenic ETEC K88 to Caco-2 cells, the inhibitory ability related to the concentration and adding order of bacteria.