17株益生菌对大肠杆菌和金黄色葡萄球菌抑制作用研究

Study on inhibitory effects of 17 strains of probiotics on Escherichia coli and Staphylococcus aureus

为了快速检测益生菌对革兰氏阳性菌(金黄色葡萄球菌)和革兰氏阴性菌(大肠杆菌)的体外抑制作用,试验采用间隔24 h先后或同时定植的体外抑菌法,分别观察从不同样品中分离所得乳杆菌、芽孢杆菌等17株常见益生菌与常见致病菌(大肠杆菌、金黄色葡萄球菌)竞争排斥作用,根据建立的益生菌对致病菌抑制效果的量化标准进行计分,分值越高表明抑制活性越强。结果表明:当益生菌早期定植时,除了蔬菜芽孢杆菌GXNN20201206-5对2株致病菌生长没有抑制作用外,其余16株益生菌对2株致病菌的生长都有一定的抑制作用;当致病菌早期定植时,致病菌仅对4株益生菌有抑制作用;当益生菌与致病菌同时定植时,嗜酸乳杆菌GX20200417-2、粪肠球菌GX20200417-3、植物乳杆菌GX20200417-4、副干酪乳杆菌GX20200417-5均对大肠杆菌的抑制作用最好,植物乳杆菌GX20200417-4对金黄色葡萄球菌的抑制作用最好。说明益生菌对致病菌的抑制作用不仅具有菌株特异性,还与定植时间顺序有关。

In order to rapidly detect in vitro inhibitory effect of probiotics against Gram-positive bacteria(Staphylococcus aureus)and Gram-negative bacteria(Escherichia coli),in the experiment,the in vitro antibacterial method was used to colonize successively or simultaneously at intervals of 24 h;the competitive exclusion effect of 17 common probiotics such as Lactobacillus and Bacillus isolated from different samples on common pathogenic bacteria(Escherichia coli,Staphylococcus aureus)were observed respectively.According to the established quantitative standard for judging the antibacterial effect of probiotics on pathogenic bacteria,the higher the score,the stronger the mutual inhibitory activity was.The results showed that when probiotics were colonized in the early stage,except for Bacillus vegicus GXNN20201206-5,which had no inhibitory effect on the growth of the two pathogens,the other 16 probiotics had a certain inhibitory effect on the growth of the two pathogens.When the pathogenic bacteria colonized in the early stage,the pathogenic bacteria only had inhibitory effect on four strains of probiotics.When probiotics and pathogenic bacteria were colonized at the same time,Lactobacillus acidophilus GX20200417-2,Enterococcus faecalis GX20200417-3,Lactobacillus plantarum GX20200417-4,and Lactobacillus paracasei GX20200417-5 had the best inhibitory effect on Escherichia coli;Lactobacillus plantarum GX20200417-4 had the best inhibitory effect on Staphylococcus aureus.The results suggested that the inhibitory effect of probiotics on pathogenic bacteria was not only strain-specific,but also related to the time sequence of colonization.