Efficient method for separating Campylobacter jejuni

Abstract

The invention discloses a method of enrichment separation of Campylobacter jejuni, provides a better basic for follow-up study of target bacteria, and relates to the field of biology technology. The method comprises steps of: covalently coupling broom molecules and antibodies, coating antibody-modified broom molecules with long-chain biotin molecules, capturing target bacteria in a sample solution via broom molecules that are modified by the antibodies and the long-chain biotin molecules, identifying streptavidin-modified nano-magnetic-beads and coupling with long-chain biotinylated broom molecules in the sample solution, separating and re-suspending the captured bacteria. Because the re-suspending solution can be used for follow-up analyses directly, the method provide by the invention is even more suitable for magnetic separation of bacteria in complex matrixes compared with conventional magnetic separation of bacteria, and rises the separating efficiency of target bacteria in samples.

Description

technical field [0001] The invention relates to the field of biotechnology, in particular to a method for isolating food-borne pathogenic bacteria based on nano magnetic beads. Background technique [0002] Foodborne pathogen contamination is one of the major problems of food safety in my country. According to WHO statistics, 2.2 million people in the world die every year due to food-borne diseases, and about one-third of people in developed countries are infected with food-borne diseases every year. In my country, the number of cases of food poisoning is between 200,000 and 400,000 per year, most of which are caused by food-borne pathogens except for accidents. Campylobacter jejuni is one of the common food-borne pathogens, which can cause a variety of diseases in humans. The symptoms are mainly diarrhea and abdominal pain, sometimes fever, occasional vomiting and dehydration. It has been considered as the cause of bacterial diarrhea in humans all over the world. the main...

AI Technical Summary

Problems solved by technology

However, the current separation technology based on micron-scale immunomagnetic beads has many limitations: 1) The specific surface area of ​​micron-sized magnetic beads is relatively small, which reduces the capture efficiency of magnetic beads; Bacterial cells are combined through a multiphase reaction (multiphase reaction), and it usually takes longer to specifically capture bacterial cells in the food matrix; 3) Micron magnetic beads have poor monodispersity and are prone to self-disruption in the food matrix solution. Aggregation or formation of precipitates; 4) Traditional immunomagnetic separation techniques often directly couple antibody molecules to immunomagnetic beads, which often leads to greatly reduced antibody activity and changes in the spatial direction of antibodies. The steric hindrance effect between antibodies reduces the capture efficiency of antibodies. 5) The nature of the food matrix is ​​complex and the concentration of non-target pathogenic bacteria is large. Micron magnetic beads are prone to non-specific adsorption, and it is difficult to realize the detection of food samples. Specific separation of target bacteria; 6) Too high concentration of micron magnetic beads will cause damage to bacterial cells (magnetic field causes magnetic beads on the cell surface to attract each other, causing cells to be squeezed or even ruptured), resulting in failure of separation; 7) Magnetic beads When coupling antibodies, hydrophobic adsorption or chemical coupling is generally used to couple active antibodies on the surface of magnetic beads

The distance between the antibody and the surface of the magnetic bead is too close, the nature of the magnetic bead itself and the residual hydrophobic or strong hydrophilic groups on the surface are likely to cause changes in the spatial conformation of the antibody, resulting in a decrease in the biological activity of the antibody

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