动物造模,仓鼠莱姆病感染 z-bio 2023-09-26 765

　　1. Modeling method: Borrelia burgdorferi was extracted from the cerebrospinal fluid of infected patients, and this spirochete was cultured in a medium containing BSK at a temperature of 35 ℃, with a growth cycle of 5 days. Add fresh BSK to maintain the content of spirochetes in the suspension at 5 × 1000 000/ml. Select Syrian hamsters for modeling experiments, weighing 80-100g, and add 5 × 1000 000/ml suspension of Borrelia burgdorferi at 10000 rpm to remove impurities from the upper layer. The model can be made by intravenous injection or subcutaneous injection of the hind foot, with an injection volume of 0.2-0.4 ml of the aforementioned spirochete suspension. After 14 days, the presence of spirochetes can be detected in 6 organs. After 3 weeks of infection, the animal model experienced swelling and limping in the hind paws, and severe arthritis symptoms worsened as the disease progressed.

　　2. Model detection methods

　　(1) Serological testing: Enzyme linked immunosorbent assay is used to detect the titer of anti Borrelia burgdorferi antibodies in hamster infection models. The serum extracted from hamsters should be diluted 1:20 and detected using rabbit anti hamster immunoglobulin G antibodies. Simply put, add 100 serum containing Borrelia burgdorferi to the pore plate μ Incubate for 15 minutes. After incubation, rinse with alkaline phosphatase and add diluted rabbit anti hamster immunoglobulin G. The model infected with spirochete for 3 weeks began to show an increase in antibody titers in the blood, and by 5 weeks, the antibody titer reached its peak.

　　(2) Histopathological examination: Models infected for 1 or 3 weeks were euthanized by inhaling carbon dioxide. Myocardial, renal, brain, skin, joints, muscle tissue, etc. were fixed in a 10% formalin solution, dehydrated, paraffin embedded, sliced, stained with hematoxylin eosin, and detected with a dark field microscope for Chabsiella pneumoniae. Under the microscope, it can be seen that inflammatory cells such as neutrophils and monocytes infiltrate around the heart, joints and other tissues of the infected model animals. Thickening of joint synovium.

　　(3) Pathogen isolation and culture: Small pieces of skin tissue, cerebrospinal fluid, and visceral tissue from the injection site of the hamster model 3 weeks after infection were inoculated onto BSK II medium, with a temperature maintained at 33 ℃. After 5-7 days, a dark field microscope examination revealed a positive culture, which was passed down for further identification and confirmation.

　　(4) PCR method detection: After 3 weeks of infection, skin tissue or non injection site tissue is taken from the animal's injection site, and processed to detect the presence of Borrelia burgdorferi DNA using PCR method.

　　3. Model characteristics: The infection rate of hamsters against ticks on the shoulder process can reach 55% to 75%. Animals infected with Lyme disease can easily develop synovial hypertrophy of the posterior tibia and toe joints, accompanied by local ulcers and covering with adhesive fibrin. Under the microscope, it can be seen that a large number of neutrophils, lymphocytes, and microvascular dilation are easily present in the synovium and tendon tissues of the joint. Hamster Lyme disease infection models are often used in experimental transmission research, vector efficacy, and host potential analysis of Lyme disease.