动物造模,猪链球菌2型仔猪模型 z-bio 2021-12-21 443

　　(1) Replication method (1) Intravenous vaccination: SPF pigs are weaned 12 days after birth, and the piglets are given an intravenous injection of 2 ml of 1.185 x 1000000000 CFU/ml Streptococcus suis type 2 bacterial solution. On the second day after intravenous injection of Streptococcus suis, pigs developed central nervous system symptoms, joint swelling, high fever up to 40°C, fibrin nodules in the liver and intestines after dissection, excessive joint effusion, and moderate fibrosis. Symptoms may appear. Synovitis of lymphatic tissue. ②Intranasal inoculation: 1 hour before bacterial inoculation, first instill 5 ml of 1% acetic acid (pH 3.3) into the nose, and then inoculate the nose with 1.23 x 1000000000 CFU/ml 2 ml bacterial solution and store it in the environment. At 26.5°C. Coats appeared on the second day of vaccination, and some animals showed lethargy, severe central nervous system symptoms and high fever (up to 41°C) on the fourth day. After an autopsy, fibrin nodules, excessive joint effusion and lungs were found. Under the microscope, there are purple-red solid lesions, severe fibrous purulent meningitis and multiple suppurative interstitial pneumonia.

　　(2) Model characteristics The advantage of intravenous injection of Streptococcus suis is that it is convenient, the number of bacteria inoculated is easy to control, and the clinical symptoms produced are similar to human infections, but the method of infection is different from the natural infection method. }The disease is natural, because the route of exposure is oral and nasal infections, so the intranasal vaccination model is of great value for pathogen research and vaccine efficacy testing. Intranasal vaccination usually does not or only causes self-limiting disease. Acetate may be allergic to animal models caused by Streptococcus suis. Stimulation of the upper respiratory tract After treating animals with acetic acid and injecting Streptococcus suis into the nose, the symptoms are similar to spontaneous infections.

　　(3) Comparative medicine The clinical symptoms of people infected with Streptococcus suis are acute attack, high fever, headache and other systemic poisoning symptoms, toxin shock, meningitis are the main clinical symptoms, and even severe, if they have died. Streptococcus suis infection can cause meningitis, sepsis, pneumonia, arthritis and sudden death. Experimental pigs are good model animals because the two symptoms are similar. Stimulating the nasal cavity with intravenous bacteria and acetic acid, and then inoculating the nasal cavity can establish a good model for studying the pathogen, pathogenic mechanism and vaccine of Streptococcus suis.