Method for rapidly detecting cronobactersakazakii based on magnetically-captured nanogold colorimetric method

Abstract

The invention discloses a method for rapidly detecting cronobactersakazakii based on a magnetically-captured nanogold colorimetric method, and belongs to the technical field of food safety. The methodcomprises the following steps: disrupting bacterial cells in a substance to be detected to release DNA, extracting for removing impurities to obtain a crude extruded DNA solution, adding amino magnetic beads into the crude extruded DNA solution, and incubating and capturing the DNA; establishing a cronobactersakazakii-specific PCR, and using the captured DNA as a template for PCR amplification; and designing a DNA probe of the cronobactersakazakii, incubating the colloidal gold and the DNA probe, then aging to obtain a colloidal gold probe, hybridizing a PCR product with the colloidal gold probe, adding a MgSO4 solution and observing the color change. By the method, the steps are simple, the specificity is high, the time is short, rapid detection can be achieved, expensive reagents such as an antibody are not needed, and the cost is low; and the method is applicable to rapid detection of the cronobactersakazakii in food.

Description

technical field [0001] The invention relates to a method for rapidly detecting Cronobacter sakazakii using a magnetically captured nano-gold colorimetric method, which belongs to the technical field of food safety. Background technique [0002] Cronobacter sakazakii (Cronobacter sakazakii), formerly Enterobactersakazakii, is a Gram-negative, non-spore-forming, stubby bacillus with flagella all over the body, motile and facultatively anaerobic. The bacterium can cause death in infants and young children, especially for premature infants, infants with low birth weight or immunocompromised infants. In severe cases, it can cause sepsis, meningitis or necrotizing enterocolitis, and the case fatality rate of the reported cases is as high as 20 % to 50%, survivors often have severe neurological sequelae. Cronobacter sakazakii is the main microbial safety indicator of infant formula milk powder. The detection and control of Cronobacter sakazakii has become an important factor affec...

AI Technical Summary

Problems solved by technology

[0006] In order to solve the problem in the prior art that the method for capturing Cronobacter based on immunomagnetic bead technology requires specific antibodies, and the preparation of antibodies is very difficult and costly, and is not suitable for batch on-site detection, the present invention provides a method based on The method for rapid detection of Cronobacter sakazakii by magnetically captured nano-gold colorimetric method adopts the following technical scheme:

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