动物造模,狗莱姆病感染动物模型 z-bio 2023-09-26 841

　　1. Modeling method: Select dogs without other pathogen infections, aged 6-8 weeks, each animal has a separate room, and is fed with commercial feed and sterile drinking water. Expose the puppy to an environment containing ticks carrying Borrelia burgdorferi. The ticks come from areas with high incidence of Lyme disease in China and have been tested in the laboratory for carrying pathogens. Before being used in the experiment, they were raised in an environment at 10 ℃ and a humidity of 94%. Cut off the hair on the left chest of the experimental animal, and place the hard tick carrying the pathogen in that area, so that its body is completely congested by biting the host and removed on the 7th day. To ensure that the experimental animals are completely infected, the above experiment was repeated on the 14th day. Conduct daily clinical signs testing to check the dog's body temperature, weight, and presence of affected limbs, as well as swelling. After the tick bites the experimental animal dog, only a few model animals experienced a temperature increase above 39.4 ℃ for 1 day, and occasionally a temperature increase continued for 2 days. Dogs infected with Lyme disease can experience limb or one limb limping, which can last for 3-5 days without any medication treatment. Limping occurs approximately 71 days after infection in the model animal, mainly in the left foreleg near the tick bite site, which is prone to arthritis symptoms. As the infection time prolonged, claudication was observed in all limbs of the experimental model, and it occurred every 2-14 days.

　　2. Model detection methods

　　(1) Serological testing: Two weeks after the initial infection, serum samples from the model were taken for anti Borrelia burgdorferi antibody testing. Using computer-controlled dynamic enzyme-linked immunosorbent assay technology for testing. Detect the serum of all animal models together to avoid bias errors in experimental results. Within 90 days after infecting experimental dogs with Borrelia burgdorferi, the titer of antiviral spirochetes in the body significantly increased, and thereafter, the antibody titer only showed a slight increase.

　　(2) Pathogen isolation and culture: After 4 weeks of modeling, the animal model was euthanized and tissues from 25 parts such as the skin and heart were collected. To avoid cross infection, each animal model was treated with a set of surgical instruments. The collected tissues include skin tissue near the bite site, tissue from six synovial regions (shoulder, elbow, knee), forelimb muscles and fascia (triceps, forelimb fascia), neck skin, axillary skin, lymph nodes, pericardium, etc. Place 0.5g of the obtained tissue into 9ml BSK medium for cultivation, and after 5 weeks, live B. burgdorferi spirochetes can be detected under a microscope. Place the skin and lymph nodes of the bite site of the model in BSK medium, culture at 32 ℃, and after 5 weeks, live B. burgdorferi spirochetes can be detected under a microscope.

　　(3) Polymerase chain reaction (PCR) detection: PCR can be used to detect specific DNA fragments of Borrelia burgdorferi in animal blood and tissues. This method can detect Borrelia burgdorferi DNA in blood, skin, tissue, and cerebrospinal fluid. The skin sample culture and PCR results of the model dog showed positive infection with Borrelia burgdorferi.

　　(4) Histopathological examination: experimental model for infection of 505-600 days