Research on the function and application of lecithin-Tween tryptone soy culture medium_Industrial additives

Background^[1-3]

Lecithin Tween Tryptone Soy Medium is mainly used for the culture and enumeration of most bacteria on the surface of objects, and does not have the function of microbial identification and drug susceptibility identification.

In the lecithin-Tween tryptone soy culture medium, peptone provides nitrogen source, vitamins and growth factors; glucose provides energy; potassium dihydrogen phosphate is the buffer; agar is the coagulant of the culture medium. Provides a richer nutrient base, suitable for the growth of most microorganisms.

Lecithin Tween Tryptone Soy Culture Medium is mainly used for the detection of sedimentation bacteria in clean environments, and is used in conjunction with planktonic bacteria samplers for the detection of planktonic bacteria in clean environments. Sterility inspection should be carried out in a one-way air area with a local cleanliness level of 10000 or in an isolation system. The entire process should strictly comply with aseptic operations to prevent microbial contamination. Measures to prevent contamination must not affect Detection of microorganisms in test products. The one-way flow air area, work surface and environment should be regularly tested for cleanliness according to the current national standards of “Test Methods for Suspended Particles, Planktonic Bacteria and Sedimented Bacteria in Clean Rooms (Areas) of the Pharmaceutical Industry” to verify the role of antioxidants. The isolation system should be verified according to relevant requirements, and the cleanliness of its internal environment must meet the requirements of sterility inspection. Routine inspections also require monitoring of the test environment. The sterility inspection method is a method used to check whether drugs, medical devices, raw materials, excipients, and other items that require sterility in the Pharmacopoeia are sterile. If the test product meets the requirements of the Sterility Inspection Law, it only means that no microbial contamination was found in the test product under the inspection conditions.

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For the isolation and identification of Riemerella anatipestifer and the development of bivalent inactivated vaccine

Duck infectious serositis is a contagious disease caused by Riemerella anatipestifer. Ducks aged 2 to 8 weeks are most susceptible to the disease, with acute or chronic septicemia. Sick ducks often have symptoms such as increased eye and nasal secretions, diarrhea, ataxia, and head and neck tremors. Necropsy revealed fibrinous pericarditis, perihepatitis, airsacculitis, and meningitis in some cases, caseous salpingitis, conjunctivitis, and arthritis, with a mortality rate of 10% to 80%. The growth of over-resistant ducks was retarded, and feed return was significantly reduced. Because the disease can be transmitted through contaminated feed, drinking water, droplets, dust, etc. through the respiratory tract, digestive tract, and skin lesions, it persists in infected duck farms and is difficult to extinguish. Therefore, it is considered to cause the most serious economic losses to the duck industry. One of the epidemics. The serotype 1 RA-sd3 strain and the serotype 2 RA-sd2 strain with good immunogenicity were selected to prepare Riemerella anatipestifer hyperimmune serum, and a method for detecting Riemerella anatipestifer antibodies in duck serum was established. Microagglutination test (MAT) method. In a 96-well V-type microreaction plate, use 50 μL of 0.85% sterile saline to dilute 50 μL of the serum to be tested, add 50 μL of agglutination antigen (OD600 value = 1.452), and place it in a wet box at 37°C for reaction. After 4 hours, you can view the reaction results. The prepared agglutination antigen can be stored for 5 months at 4°C. This method is specific, sensitive, low-cost, simple and easy to promote and use. Select Riemerella anatipestifer type 1 RA-sd3 strain and type 2 RA-s BASF pigment d2 strain with good immunogenicity to inoculate the tryptone soy broth medium, harvest the culture, and adjust the bacterial count to 1.2×1010CFU/ml , inactivate with formaldehyde solution with a final concentration of 0.3%, mix in equal amounts, and emulsify according to the ratio of water phase: oil phase = 1:2 to prepare a bivalent inactivated vaccine for duck infectious serositis. Use safety-tested vaccines to subcutaneously immunize 3-7-day-old ducklings around their necks, 0.3ml/bird. After 21 days, the protection rate against the virus can reach over 9/10, and the immune protection period can last for two months.