动物造模,肠出血性大肠杆菌猪感染模型 z-bio 2023-10-12 1714

　　When using pigs as infection model animals, it is common to use sterile piglets obtained from cesarean section surgery and feed them with reconstituted milk in a microbial isolation environment throughout the experimental process. If the feeding is smooth and healthy, it can be used for experiments 24 hours after birth. The bacterial restriction pig model successfully simulated symptoms such as A/E damage to the large intestine and disappearance of microvilli near the adhesion site after EHEC infection.

　　(1) Infection method: Oral Escherichia coli.

　　(2) Infection dose: Each animal is given 10ml of bacterial solution washed and toxin removed by gavage with a gavage needle, which contains 4 viable bacteria × 10 to the 9th power.

　　(3) Result: Diarrhea occurs 2 hours after infection, until neurological symptoms, lying down or death occur. Except for diarrhea symptoms, almost all infected piglets have neurological symptoms, including motor disorders, ataxia, reclining position, and some piglets die overnight. But the results of blood culture showed that severe neurological symptoms were not related to systemic bacterial infections in the body as a whole. Animals vaccinated with wild-type E. coli experienced A/E damage to the surface and glandular epithelium of the cecum and colon, and the damage area continued to expand with the prolongation of infection time. The severely damaged mucosal surface is flat, disorderly arranged, and lacks or lacks goblet cells. The surface of the glandular epithelium is also affected. All animals with observed neurological symptoms observed micro hemorrhagic lesions in the cortex histologically, and no renal lesions in human infections were observed.

　　The study using this model shows that eae plays an important role in the formation of A/E injury, and Stx2 producing strains are more toxic than Stx1 producing strains. Due to the need for special animal facilities and the higher cost of animal model preparation, the application of EHEC infection models in bacteria limited pigs is limited.