Efficient method for separating meticillin-resistant Sta-phylococcusaureus

Abstract

The invention discloses a method of enrichment separation of meticillin-resistant Sta-phylococcusaureus (MRSA), 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 biomedicine, in particular to a method for isolating pathogenic bacteria based on nano magnetic beads. Background technique [0002] Methicillin-resistant Staphylococcus aureus ( Meticillin-resistant Staphylococcus aureus, MRSA ) is the most common pathogen of nosocomial infections. It is also an important pathogen causing suppurative diseases, food poisoning and toxic shock syndrome, and the infection caused by it has become a rather difficult problem in clinical treatment. Its purulent infection can range from small skin lesions such as boils and carbuncles to serious infections such as pneumonia, mastitis, phlebitis, meningitis, and inflammation of the urinary system, and can reach deep to cause osteomyelitis and endocarditis. MRSA It is a serious pathogenic bacterium of nosocomial infection, which is often found around the indwelling catheter in the body after trauma or operation. MRSA It can also cause fo...

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), which usually takes longer to specifically capture bacterial cells in the matrix; 3) Micron magnetic beads have poor monodispersity and are prone to self-aggregation or Precipitation; 4) The traditional immunomagnetic separation technology often directly couples antibody molecules to immunomagnetic beads. This process often leads to a greatly reduced activity of the antibody and changes in the spatial direction of the antibody, increasing the inter-antibody interaction. steric hindrance effect, which reduces the capture efficiency of antibodies. 5) Whole blood, secretions and other matrices have complex properties and the concentration of non-target pathogenic bacteria is high. Micron magnetic beads are prone to non-specific adsorption, and it is difficult to achieve sample detection. Specific separation of target bacteria in liquid; 6) Too high concentration of micron magnetic beads will cause damage to bacterial cells (magnetic field causes magnetic beads on the surface of cells to attract each other, causing cells to be squeezed or even ruptured, resulting in failure of separation; 7) Magnetic When beads are coupled to antibodies, hydrophobic adsorption or chemical coupling is generally used to couple active antibodies to 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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