Test method for evaluating in-vitro antibacterial activity of antibacterial substance

Abstract

The invention specifically discloses a test method for evaluating the in-vitro antibacterial activity of an antibacterial substance, belonging to the technical field of biological control. According to the method, a methylene blue agar plate containing bacteria is used for agar-plate-diffusion-process in-vitro antibacterial activity test. The method is visual and simple, realizes evaluation through observation of a colored inhibition zone and overcomes the disadvantage of difficulty in accurate measurement of the diameter of an inhibition zone due to deep and turbid colors and complex components during in-vitro antibacterial test of traditional Chinese medicines or other to-be-measured substances with similar properties by using traditional agar plate diffusion processes.

Description

technical field [0001] The invention relates to the technical field of biological control, in particular to a test method for evaluating antibacterial activity of antibacterial substances in vitro. Background technique [0002] In vitro antibacterial test is a test to determine the sensitivity of microorganisms to a certain substance in vitro. It is often used to evaluate the activity of inhibiting and killing pathogenic bacteria. It has been widely used in scientific research, production and clinical, such as screening of antibacterial drugs, tracking during extraction, Determination of antimicrobial spectrum, drug susceptibility test to guide clinical medication, etc. The agar plate diffusion method is one of the most commonly used methods at present. [0003] The traditional agar plate diffusion method is to spread the indicator bacteria on the surface of the agar or evenly mix it into the agar, and then use the paper method, Oxford cup method, punching method and other ...

AI Technical Summary

Problems solved by technology

However, the extract of traditional Chinese medicine has special properties, and its diffusion phenomenon in the agar plate is different from that of antibiotics. The in vitro antibacterial test of traditional Chinese medicine cannot completely copy the in vitro antibacterial test of antibiotics.

The main characteristics of Chinese medicine extracts are: (1) Dark and turbid color: After the drug diffuses, a darker and turbid drug diffusion circle appears in the agar. This circle coincides with the transparent circle where bacteria do not grow, which affects the measurement of the diameter of the inhibition zone. It is difficult to visually evaluate the antibacterial activity

like figure 2 Shown: In the two wells (01)(02) on the agar plate, the antibacterial phenomenon of the water extract of Scutellaria baicalensis with deep color and turbidity is diffused, wherein b1 is the dark brown traditional Chinese medicine diffusion circle (inner circle), and b2 is the light brown traditional Chinese medicine diffusion circle (outer circle). circle); (03) (04) two holes are colorless and clear antibiotic ceftriaxone sodium diffusion antibacterial phenomenon, wherein b3 is a transparent antibacterial zone, it can be seen that when the traditional plate agar diffusion method is used for antibacterial test, the antibiotic is colorless and clear , the drug diffusion zone does not cover the transparent zone of inhibition and is easy to measure, while the dark and turbid color of traditional Chinese medicine covers the transparent zone of inhibition, which requires careful observation or even the area where bacteria do not grow, making it difficult to distinguish and measure the zone of inhibition; (2) The composition is complex: antibiotics Generally, the composition is single, and the distance from the diffusion center is different for different drugs, but the concentration is different but the composition is the same

However, traditional Chinese medicine extracts often have complex components, and the diffusion speed of each component is different. The concentration and composition of the drug at different positions from the diffusion center are different. Therefore, the size of the bacterial non-growth circle is not only related to the concentration of the drug but also related to the complex components of the drug.

[0005] To sum up, the traditional agar plate diffusion test still has disadvantages in the in vitro antibacterial activity evaluation of traditional Chinese medicine and its similar properties of dark turbidity and complex components. Looking for a more intuitive and effective indicator of its antibacterial activity In vitro antibacterial methods have important application value for the development of antibacterial substances

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