Selective chromogenic culture medium of listeria monocytogenes and preparation method of selective chromogenic culture medium

Abstract

The invention provides a selective chromogenic culture medium of listeria monocytogenes. Every 1000ml of the culture medium comprises the following components by weight: 5-20g of heart-brain extract, 2-6g of agar, 2-5g of peptone, 0.1-1g of a specific enzyme chromogenic substrate, 0.05-20g of dimethylformamide, 0.2-0.5g of magnesium sulfate, 0.2-0.5g of lithium chloride, 0.3-0.6g of an oxygen scavenger, 0.2-1.0g of 3-morpholino-propane-1-sulfonic acid, 6-17g of a bacteria inhibitor and the balance being water; the specific enzyme chromogenic substrate is 5-bromo-4-chloro-3-indolyl-inositol-1-phosphate. A listeria monocytogene specific chromogenic substrate is made into the selective chromogenic culture medium, so that the specific selection and chromogenic functions of listeria monocytogenes are realized at low cost, and the problem that the listeria monocytogenes are difficult to isolate, culture and identify is solved.

Description

technical field [0001] The invention relates to a selective chromogenic medium suitable for Listeria monocytogenes and a preparation method of the selective chromogenic medium. Background technique [0002] Listeria was first isolated from rabbits and guinea pigs in the United Kingdom in 1926, and its pathogenicity to humans was confirmed in 1929. There are 6 species of the bacterium, Listeria monocytogenes (referred to as Listeria monocytogenes, LM), Listeria innocua, Listeria sierra, Listeria welis, Listeria ovis bacterium and Listeria gravidarum. Among them, Listeria monocytogenes is pathogenic to humans and animals, Listeria ovis is pathogenic to animals, and the rest are non-pathogenic. Listeria monocytogenes is ubiquitous in soil, animals, and aquatic products. The foods most involved are soft cheeses, dairy products, sausages, smoked fish, lettuce foods, deli foods, and frozen ready-to-eat foods. Because of its unique physiological characteristics, it can cause hum...

AI Technical Summary

Problems solved by technology

However, to date no assay has met all the criteria listed above

The traditional method is time-consuming, heavy workload, and does not meet the current needs of rapid and sensitive detection of microorganisms

Compared with the traditional method, the molecular biology detection method greatly reduces the workload, but the positive samples detected should be compared with the traditional method, and the detection is prone to false negative and false positive results

[0004] At present, the selective medium used for the isolation of Listeria monocytogenes, including the chromogenic medium, can only selectively cultivate the Listeria group but cannot selectively cultivate the Listeria monocytogenes, and Listeria monocytogenes other than Listeria monocytogenes The genus is non-pathogenic or only pathogenic to animals. The microbiological identification of Listeria monocytogenes requires complex biochemical reaction tests, and the time required for identification is too long, which affects clinical diagnosis and treatment.

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