Prokaryotic expression and purification method for listeria monocytogenes hemolysin O

Abstract

The invention discloses a prokaryotic expression and purification method for listeria monocytogenes hemolysin O, which comprises the following steps: 1) performing PCR augmentation, PCR electrophoresis and PCR recovery according to a gene sequence of listeria monocytogenes registered on an NCBI and a polyclone locus design primer of a vector PMD 18-T to be coupled, and performing a DNA coupling reaction on a PCR regenerant; 2) preparing and inverting colibacillus competent cells; 3) preparing a little plasmid DNA in an alkaline process; 4) recombining and constructing expression plasmids and inductively expressing recombinants; and 5) purifying the affinity chromatography and purification of expression protein. The listeria monocytogenes hemolysin O protein is prepared to acquire colloidal gold Immunochromatographic test strips prepared by antibodies, so that the listeria monocytogenes can be detected quickly and accurately in the process of food detection.

Description

technical field [0001] The invention relates to a prokaryotic expression and purification method of listeria monocytolysin O. Background technique [0002] Agricultural products and food safety are a global problem, and food-borne diseases are the main problem of food safety. In recent years, food-borne disease incidents have occurred frequently at home and abroad, and Listeria monocytogenes plays a major role in food-borne bacterial poisoning. Listeria is the most important human food-borne pathogen, and it is one of the four major pathogens in food in the 1990s, and it is listed as one of the seven major food-borne pathogens in the United States. [0003] Listeria monocytogenes widely exists in nature, is not easy to be frozen and thawed, and can withstand high osmotic pressure. It can be found in soil, surface water, sewage, waste water, plants, silage feed, and rotten vegetables. , so animals can easily ingest the bacteria and spread it through the oral-fecal route. Ac...

AI Technical Summary

Problems solved by technology

L. monocytogenes mutants that do not produce LLO can survive for some time in the cytosol of non-phagocytic cells, but cannot reproduce and cannot infect other cells because they cannot escape the phagosome

In addition, LLO is also involved in other reactions related to the pathogenicity of Listeria monocytogenes. Studies have shown that: a Listeria monocytogenes infection of dendritic cells in the spleen and bone marrow of mice can lead to cell apoptosis; L. monocytogenes mutants that do not produce LLO cannot induce apoptosis, whereas purified LLO can cause this programmed cell death

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