动物造模,小鼠脑脊髓炎 z-bio 2021-11-30 741

　　Purpose: To understand the natural infection of mouse encephalomyelitis virus (TMEV), and to explore the distribution of the virus and changes in serum antibodies in various organs and tissues of mice infected with TMEV.

　　Methods: Enzyme-linked immunosorbent assay (ELISA) and fluorescence quantitative RT-PCR (qRT-PCR) were used to detect SPF mice, mice raised in an open environment and wild Rattus norvegicus collected in Guangdong from 2010 to 2015. Clinical samples were tested for TMEV. 36 ICR mice were inoculated with TMEV BeAn virus in the brain, and the clinical symptoms of the animals were observed every day. On the 0, 3, 7, 10, 17, 21, 31, 39, and 46 days of inoculation, 3 animals were treated at each time point. Euthanasia, necropsy and take serum and tissue samples for TMEV testing.

　　Results: The positive rate of TMEV antibody in SPF mice was 5.29% (n=2834), and the positive rate of nucleic acid was 27.27% (n=457); the positive rates of antibody and nucleic acid in mice raised in an open environment were 71.95% (n= 82) and 53.66% (n=82); the positive rate of nucleic acid in wild Rattus norvegicus was 25.93% (n=27). Only two of the TMEV-positive mice showed obvious clinical symptoms. The contents of the cecum, feces and brain are the best samples for qRT-PCR detection. Viral nucleic acid was detected in the brain, heart, liver, lung and stomach on the 3rd day after ICR mice were inoculated with TMEV BeAn virus in the brain, but no viral nucleic acid was detected in the spleen, kidney and cecum. The virus in the liver, heart, lungs and stomach was completely eliminated on the 10th day after vaccination, and the virus in the brain continued to exist until the end of the 46th day. Antibodies can be detected in mice on the 7th day after infection, and then the antibody level gradually rises. The positive rate of antibody reached 100% on the 17th day after vaccination, and the high antibody level can be maintained up to 46 days. The artificially infected mice showed a recessive infection, and did not show obvious symptoms and pathological changes in the eye.

　　Conclusion: Both experimental mice and wild Rattus norvegicus in Guangdong area have TMEV infection, and the infection rate is relatively high. Mice were inoculated with TMEV BeAn strain and showed a recessive infection. The mice can produce antibodies and persist on the 7th day after infection. The virus exists for a short time in the liver, heart, lungs and stomach of infected mice, but for a long time in the brain. The qRT-PCR and ELISA detection methods have good consistency, and the qRT-PCR detection method can be used as a powerful supplement to the national standards for laboratory animals.