动物造模,脑脊髓炎病毒 z-bio 2022-06-07 378

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

　　METHODS: Enzyme-linked immunosorbent assay (ELISA) and quantitative RT-PCR (qRT-PCR) detection methods were used to detect SPF mice collected in Guangdong from 2010 to 2015, mice raised in an open environment and wild Rattus norvegicus. 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 0th, 3rd, 7th, 10th, 17th, 21st, 31st, 39th, and 46th day of inoculation, 3 animals were treated at each time point. Euthanasia, necropsy and taking serum and tissue organ samples for TMEV detection.

　　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 rate of antibody and nucleic acid in mice raised in an open environment were 71.95% (n= 82) and 53.66% (n=82); the nucleic acid positive rate in wild Rattus norvegicus was 25.93% (n=27). Only two of the TMEV-positive mice exhibited significant clinical symptoms. Cecal contents, feces, and brain are the best samples for qRT-PCR detection. On the 3rd day after inoculation of TMEV BeAn virus in the brain of ICR mice, viral nucleic acid was detected in the brain, heart, liver, lung and stomach, but no viral nucleic acid was detected in the spleen, kidney and cecum. The virus in the liver, heart, lungs, and stomach was completely cleared by day 10 post-inoculation, and the virus in the brain persisted until the end of the trial on day 46. Antibodies could be detected on the 7th day after infection in mice, and then the antibody levels gradually increased. The positive rate of antibodies reached 100% on the 17th day after inoculation, and the high antibody level could be maintained until the 46th day. The artificially infected mice showed a latent infection, and there were no obvious clinical symptoms and pathological changes in the eyes.

　　Conclusion: TMEV infection exists in both experimental mice and wild Rattus norvegicus in Guangdong, and the infection rate is high. Mice inoculated with the TMEV BeAn strain showed a latent infection, and the infected mice could produce antibodies and persisted on the 7th day. The virus persisted for a short time in the liver, heart, lung and stomach of infected mice and long-term in the brain. The two detection methods of qRT-PCR and ELISA have good consistency, and the qRT-PCR detection method can be used as a powerful supplement to the national standard for experimental animals.