动物模型,传染病 z-bo 2020-07-24 964

       After all, infectious animal models use animals for artificial infections and simulation studies. In particular, pathogens of human origin infect animals. It usually does not experience disease processes that are very similar to humans. This is also the limitation of infectious animal models. Understanding this limitation will help you better understand your animal model and use it correctly. On the other hand, it is also possible to consider why pathogens exhibit the same or different pathogenicity in different animals. This is also the focus of the research on the pathogenic mechanism of pathogenic diseases. In short, the limitations of infectious animal models include the following aspects:

　　 1. Animal restrictions

　　 Animal type and level will affect the animal model. Different animals have different genetic and biological characteristics, as well as different infectivity to pathogens. In addition, different species, breeds and strains of animals are also different, and individual differences will also affect the consistency of the model. For example, the avian influenza virus H5N1 can infect a variety of animals, including mice, rats, macaques, cynomolgus monkeys and ferrets, but the pathogenicity varies among different animals. In foreign countries, we recommend using ferrets as models. The process is similar to the patient. However, Chinese ferrets have not yet undergone laboratory animalization, and their sources are difficult. The animal's microbiology and parasite transmission status or microbiology level also affect the preparation of the model. Generally, it is recommended to use SPF-free animals for model preparation, and the influencing factors are small. In addition, animals do not suffer from all diseases when they are infected, and the model is usually based on the infection status (percentage) of the entire animal group.

　　 2. Pathogen restriction

　　The degree of activation, source, culture, quantification, standard pathogen strains, local strains and other biological characteristics of the pathogen will affect the preparation of the model. Some pathogens cannot be cultured, and interference with other microbial contamination will also affect the preparation of models. When a pathogen exists in an animal's body, it will be affected by resistance (such as immunity), and its biological characteristics will be changed accordingly through mutation or other means.

　　 3. Limitations of experimental methods

　　 Various methodologies or method conditions not found in the laboratory will affect the determination of model indicators. Many pathogens have different methods of transmission, and the planned route of infection may not be ideal. Some pathogens require quantitative detection, pathological biopsy, etc. If the laboratory conditions do not meet the requirements, the integrity of the model will be affected. Under normal laboratory conditions, the laboratory’s requirements for biological safety are different from those of animal models. For example, in the later normal environment, no AIDS primate model (SIV/SAIDS) appeared in the third-level biosafety laboratory. Severe co-infection. Fourth, the limitations of animals and humans Animals are different from humans after all, and pathogens may behave differently in different organisms. Therefore, theoretically, animals that are closer to human inheritance and evolution may be able to show similarities in disease, that is, the body's ability to respond. However, this is not absolute, because pathogens and various animals have long been accompanied, forming a complex relationship and a relatively stable drug resistance model, leading to models and disease analysis. This will be very difficult.

　　 Five application restrictions

The number and quantity of animals, the uncertainty of pathogen replication in the body, the specificity, sensitivity and reproducibility of detection methods, the frequency and requirements of killing animals, the special requirements of drugs and vaccines, and other aspects that affect and limit the model animals application. For example, primates cannot require a sufficient number of genetic homogeneity and small animals, nor can they require the number of groups required by statistics (only).