耐胃肠道环境及肠道病原菌拮抗的猪源乳酸菌的分离与筛选

从健康猪粪便筛选分离到对肠道致病菌有较强抑制特性的3株乳酸菌,分别鉴定为屎肠球菌(Enterococcus faecium)、粪肠球菌(Enterococcus faecalis)和干酪乳杆菌(Lactobacillus casei)。体外益生特性研究表明:3株乳酸菌能耐受胃肠道环境,能黏附猪小肠表面粘液,对猪源产肠毒素型大肠杆菌(Escherichia coli O139,E. coli O139)、E. coli C83905、E. coli C83524、E. coli C83529、伤寒沙门氏菌(Salmonella typhimurium O4Hi,ST O4 Hi)、金黄色葡萄球菌(Staphylococcus aureus,SA)均有较强的抑制特性。对小白鼠肠道大肠杆菌的数量进行研究,结果证明对照组大肠杆菌数量没有明显降低,而添加乳酸菌组大肠杆菌数量明显降低。对小白鼠腹腔注射E. coliC83905,乳酸菌组死亡率明显小于对照组。结果证明3株乳酸菌在猪饲料添加剂方面有较好的应用前景。

Screening of Lactic Acid Bacteria Strains for Pig Additives and the Study of Its Probiotic Properties in vitro

The lactic acid bacteria(LAB) in this experiment were isolated from the faeces of local healthy pigs.Three of them were most tolerant to in vitro antagonism of enteric pathogenic microorganisms.They were identified as Enterococcus faecium,Enterococcus faecalis and Lactobacillus casei.All of them can survive in the gastrointestinal tract and be bound to immobilized mucus material in vitro.They had antimicrobial activities against enteric pathogenic bacteria such as Escherichia coli O139,E.coli C83905,E.coli C83524,E.coli C83529,Salmonella typhimurium O4Hi and Staphylococcus aureus.The faecal E.coli counts of mice were also studied.The changes in the total E.coli population in the control groups were not significant.In the groups fed probiotics,the viable E.coli counts were significantly decreased.All the mice were injected intraperitoneally with E.coli C83905,and the death of the LAB used groups were significantly less than the control group.These results indicated that the three isolates could be used as suitable strains for widespread use in the pig additives.