在获得绿色荧光蛋白(GFP)标记的菌株K88-GFP并证明其与K88具有遗传同质性的基础上,以K88-GFP为致病菌,腹腔注射侵染小鼠,在不同时间进行眼球采血,测定血液生理生化指标,并采取不同器官或组织,培养后利用紫外光激发K88-GFP的绿色荧光,观察计数这种产肠毒素性大肠杆菌(ETEC)在小鼠体内的分布。同时通过体外抑制和活体饲喂试验,进行了益生菌的筛选。结果证实,ETEC致病菌具有较强的侵袭性,它可以侵袭小鼠肝、肾、心、肺及脑、肌肉等器官和组织,尤其可对肝、肾造成严重的损伤;筛选得到益生菌株PB JK-2,在体内外均对K88具有较好的抑制作用。Healthy Kunming mice were infected with Escherichia coli strain K88-GFP,which was marked with green fluorescence protein(GFP) gene and shared homology with enterotoxigenic E.coli(ETEC) K88,by intraperitoneal injection.Eyeball blood of the infected mice was sampled and the standard blood biochemical indexes were determined at different moment post-injection.Different organs and tissues of the mice-killed at different time points post-injection were sampled and cultured.Then,the distribution of the ETEC in the mice was observed by ultraviolet radiating of the green florescence of K88-GFP clones.Probiotics were screened by using inhibition test in vitro and mice feeding test in vivo.The results showed that the ETEC was invasive,and could infect murine liver,kidney,heart,lung,brain and muscles but damage seriously the liver and kidney.Probiotics strain PB JK-2 was selected and proved to suppress the pathogeny K88 well in vivo and in vitro.福建省青年科技人才创新计划项目(2005J064
