表达共轭亚油酸异构酶mcra基因与菌毛亚基工程益生菌的构建及特性OA

This study aimed to develop engineered probiotics based on Lactobacillus and Escherichia coli and evaluate their adhesion and invasion abilities to intestinal epithelial cells,as well as their competitive inhibition against enterotoxigenic Escherichia coli K88.The mcra gene encoding the linoleate isomerase from Lactobacillus rhamnosus GG and the genes encoding the bifidobacterial adhesive lipoprotein BOPA along with the Enterotoxigenic E.coli K88 fimbrial proteins FaeG and FaeC were successfully expressed by the delivery vectors of Lactobacillus casei ATCC 393 and Escherichia coli Nissle 1917(EcN),respectively.The engineered probiotics were designated as LC-pPG-mcra and EcN-pPG-BOPA/pBbB8K-FaeC-FaeG(EcN-BFF).The adhesion and invasive capabilities of two engineered probiotic strains to Caco-2 intestinal epithelial cells,as well as their competitive adhesion and competitive invasion against ETEC K88,were examined.The results demonstrated that both engineered strains exhibited high adhesion and invasive capabilities to Caco-2 cells.Furthermore,they significantly inhibited the adhesion and subsequent invasion to Caco-2 cells by the pathogenic K88 strain through competitive mechanisms.In conclusion,two engineered probiotics with favorable adhesion,invasion,and anti-infective properties were successfully constructed,these results lays the foundation for the application of microecological agents in the prevention and treatment of bacterial intestinal diseases.