Probiotics cloned strain of integrated single copy functional F4 pili operon gene, construction method and application

Abstract

The invention relates to the technical field of biology, in particular to probiotics cloned strain of integrated single copy functional F4 pili operon gene, a construction method and application. Themethod comprises the following steps: constructing pTargetT-nth / tppB::PtetF4 recombinant plasmid; and obtaining nonresistant single copy F4 pili gene integration cloned strain through construction ofthe probiotics cloned strain of the integrated single copy functional F4 pili operon gene. The probiotics cloned strain serves as probiotics live vaccine candidate strain and drug for the treatment ofpost-weaning diarrhea and hydropsy. Compared with the prior art, the probiotics cloned strain has the benefits that Nissle1917 probiotics original plasmid is removed, and resistance gene does not exist; recombinant bacteria can effectively improve the adhesion property to pig intestinal passage epithelial cell; mice subjected to oral immunization can produce immune serum namely anti-F4 pili IgG antibody; and serum of the mice subjected to oral immunization can obviously reduce adhesion to pig intestinal passage cell line by F4+ strain.

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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