Probiotic clone, construction method and application of integrated single-copy functional f4 pilus operon gene

Abstract

The present invention relates to the field of biotechnology, in particular to probiotic clones, construction methods and applications that integrate a single-copy functional F4 pilus operon gene, comprising the following steps: pTargetT- nth / wxya ::P tet Construction of F4 recombinant plasmid; through the construction of a probiotic clone strain integrating a single copy of the functional F4 pili operon gene, a non-resistant single copy F4 pili gene integrated clone is obtained. The probiotic cloning strain is used as a probiotic live vaccine candidate strain and a drug for treating post-weaning diarrhea and edema disease of piglets. Compared with the prior art, the beneficial effects of the present invention are as follows: the original plasmid of the Nissle1917 probiotic is removed, and there is no resistance gene; the recombinant bacterium can effectively improve the adhesion performance to pig intestinal passage epithelial cells; orally immunize mice It can produce immune serum, that is, IgG antibody against F4 pili; the serum of mice after oral immunization can significantly reduce F4 + Adhesion of strains to a porcine intestinal passage cell line.

Description

technical field [0001] The invention relates to the application field of biotechnology, in particular to the chromosomal integration, stable genetic expression and display of exogenous functional F4 pili protein of bacteria. Background technique [0002] Escherichia coli Nissle1917 is a non-pathogenic probiotic strain that has no known adverse effects on the host and can give different hosts health benefits. The main active ingredient is mainly used for human intestinal health regulation. In clinical application, the probiotic Nissle1917 strain has been modified as a carrier of genetic engineering, and the probiotic has been used in the development and manufacture of vaccines, tumor treatment, health care products, diagnostic preparations and other products. The EcNc clone is a prototype wild strain of Escherichia coli Nissle1917 genetically modified to remove two cryptic plasmids pMUT1 and pMUT2 in its cell, which has the characteristics of carrying more (large) capacity h...

AI Technical Summary

Problems solved by technology

[0005] Piglet weaning diarrhea (PWD) and piglet edema disease (ED) are clinically common diseases in the pig industry. The main pathogens are F4 and F18 pili-positive enterotoxigenic Escherichia coli ETEC, which are infected by pili adhesion and colonization of susceptible piglets Disease, leading to high mortality of piglets, low body weight, slow growth, expensive drug treatment, etc.

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