Probiotics cloned strain of integrated four-cope F18 pili operon gene and two-copy F4 pili operon gene and construction method

Abstract

The invention relates to the technical field of biology, in particular to probiotics cloned strain of integrated four-cope F18 pili operon gene and two-copy F4 pili operon gene and a construction method. The method comprises the following steps: constructing pTargetT-X::PtetF18 and pTargetT-X::PtetF4 recombinant plasmid; and obtaining nonresistant four-cope F18 pili gene and two-copy F4 pili geneintegration cloned strain through construction of the probiotics cloned strain of the four-copy functional F18 pili operon gene and the two-copy F4 pili operon gene. The probiotics cloned strain has the benefits that 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-F18 pili IgG antibody and anti-F4 pili IgG antibody; and serum of the mice subjected to oral immunization can obviously reduce adhesion to pig intestinal passage cell line IPEC-J2 by F18+ strain andF4+ strain.

Description

technical field [0001] The invention relates to the application field of biotechnology, in particular to the chromosomal integration of bacteria, stable genetic surface display and expression of exogenous functional F18 and F4 pili proteins. Background technique [0002] Escherichia coli Nissle1917 is a non-pathogenic strain that has not been found to have known harmful effects on the host so far. It can give different hosts health benefits, and this strain is used as the main active ingredient of the Mutaflor probiotic product listed in Europe. It 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 products such as vaccines, tumor treatment, health care products and diagnostic preparations. The EcNc clone is a prototype wild strain of Escherichia coli Nissle1917 genetically modified to remov...

AI Technical Summary

Problems solved by technology

[0005] Piglet postweaning diarrhea (PWD) and 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 The disease leads to high piglet mortality, low body weight, slow growth, expensive drug treatment, etc.

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