动物造模 z-bio 2021-02-07 314

　　Introduction: Animal models are the key to the study of serious infectious diseases, and are of great significance for determining the pathogenesis of diseases and developing vaccines and drugs. Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV), Human Immunodeficiency Virus (HIV), Mycobacterium Tuberculosis (M.tb), H7N9 Influenza Virus and Brucella can cause serious or fatal human diseases, and Public health causes major harm. Animal experiments involving these highly infectious pathogens need to be carried out in the ABSL-3 facility. There is no doubt that ensuring biosafety is the highest priority for animal experiment management in ABSL-3 facilities. At the same time, we cannot ignore the scientific value of animal experiments conducted in the ABSL-3 laboratory. Therefore, it is of great significance to study the key points of animal experiment management practices that consider data quality under the premise of biosafety.

　　Biological safety concept: The goal of ABSL-3's animal experiment management is to ensure reliable animal experiment data (scientific and reliable data) while ensuring safety. This goal has two meanings: one is "biosafety first", that is, ensuring the safety of personnel, the environment, and animals in experiments is the primary consideration. The second is "scientific and reliable data quality" to ensure the integrity and reliability of scientific research data, and to ensure that scientific research goals are achieved based on safety. Both the "biosafety" and the "quality of scientifically reliable data" should be considered. Therefore, we need to first establish a holistic view of biological safety that ensures the safety of animal experiments, and then optimize animal care and research procedures to obtain reliable, scientifically reliable data from animal experiments. The overall biosafety concept needs to follow the following principles:

　　 The combination of biological safety and animal welfare: Animal welfare is closely related to scientific quality, and good animal welfare conditions are conducive to the reliability of scientific data. The welfare of experimental animals requires animals to provide living conditions according to their own characteristics while achieving research purposes, so as to reduce the stress and pain of animals in experiments as much as possible, so as to maintain physical and mental health. Reducing animal stress and pain can reduce aggression, reduce aerosol pollution and animal scratches and bites, and make workers safer. When their physical and mental health is maintained, they will minimize the stress response to the environment and operation. Therefore, they have more stable physiological and biochemical indicators, and the results of animal experiments are more reliable.

　　 Combination of biological safety and experimental operation: Non-human primates (NHP) are one of the most useful experimental animals in the ABSL-3 laboratory human pathogen infection experiments. However, unlike general commercial mouse biological isolation cages (IVC), NHP animal cages sometimes need to be customized according to experimental requirements. Under the premise of considering biological safety, a customized NHP cage should be designed according to the requirements of animal welfare and convenient operation. Animal biological isolation cages make it difficult for animals to care for and handle and are not applicable. Personal protective equipment (PPE) is the main barrier to protect workers. PPE worn in an ABSL-3 facility may restrict workers’ eyesight and reduce their sense of touch. . These restrictions reduce the accuracy of the staff. Therefore, when workers use needles and other sharp tools for surgery, their chance of injury increases. Therefore, according to the specific requirements of personal protective equipment, standard operating procedures (sop) and training plans should be optimized to improve the accuracy and stability of operations, and ensure "biological safety" and "scientific and reasonable data quality." The following are the main safety issues and factors that affect the results of ABSL-3 animal experiments. On this basis, the key points of management practice are put forward.

　　 The main safety issues in the ABSL-3 facility: The safety issues of laboratory animals: When the cage lid or cage door is not properly locked, infectious animals may escape, causing potential harm to humans and the environment. Zoonoses: The pathogens of zoonotic diseases carried in animals are potentially harmful to workers. For example, herpes B virus is usually carried in rhesus monkeys, and infected animals have no symptoms. However, herpes virus B is fatal to humans. Animal scratching, biting, and kicking: If the animal is not sufficiently sedated with analgesics or anesthetics, some invasive procedures can easily cause overreactions. Workers will be scratched and bitten by infected animals. When entering the room, the staff may invade the animal's safe "flying distance" and make the animal feel trapped and unable to escape, especially in the enclosed space of ABSL-3. In this case, the animal may exhibit aggressive behaviors such as biting, scratching and kicking at people.

　　 Pathogenic microorganism safety issues: infectious aerosols: In the process of handling animals, changing cages, dumping bedding, etc., infectious aerosols are easily generated from infected animal skins, furs and bedding. These infectious aerosols are potentially harmful to workers and the environment. Sharp instrument injury: Sharp instruments such as needles, knives, and scissors are commonly used in animal operations, including but not limited to blood collection, sampling, biopsy, biopsy, anesthesia, euthanasia and autopsy. Workers may be injured by contaminated sharps and exposed to pathogens. Infectious materials for in vivo experiments and autopsy: During in vivo experiments and autopsy, workers may be exposed to animal infectious materials, such as blood, urine, feces, nasopharyngeal swabs, samples containing bacteria or viruses, body fluids, and infected animals organ. These infectious substances are potentially harmful to workers and the environment. Wastes such as animal litter, pathogen-containing culture medium and infected animal carcasses are very likely to expose people and the environment to pathogenic microorganisms.

　　 Infectious substance spills and splashes: When laboratory workers accidentally leak or splash on the workbench or on the ground, infectious substances can cause biological safety hazards to personnel and the environment. Transport of infectious disease samples: Some samples collected from infected animals can be evaluated in ABSL-3, while other samples need to be transferred from ABSL-3 for testing. Failure to safely transfer the sample from ABSL-3 poses a potential hazard to personnel and the environment. Transfer of animals between rooms in ABSL-3: Infected animals sometimes need to be transferred from the animal room to a specific operating room or autopsy room in ABSL-3 for related biopsy or autopsy. During animal transportation, people and the environment may be exposed to pathogens. Personal safety issues: In some experiments, special equipment such as X-ray, PET/CT or nuclear magnetic resonance equipment can be installed in the ABSL-3 device. This kind of equipment will produce ionizing or radioactive radiation, and we cannot ignore the related physical safety issues. Ionizing radiation damage: X-ray, CT and other imaging equipment are used to provide live imaging data during animal experiments. For example, in the monkey model studying SARS-CoV, both chest X-rays and CT scans can provide images of lung lesions. Workers exposed to X-rays of imaging equipment may be at risk of skin, hematopoietic and intestinal damage.

　　 Radiological hazards: PET/CT scans, as a biological and molecular imaging method, can non-invasively, quantitatively and dynamically monitor the functional information of labeled compounds in the body, specific organs or diseased tissues, and biological and biochemical changes in animals. It is precisely because of these advantages that PET/CT imaging is more and more widely used in animal research of infectious diseases. However, these animals need to be injected with a radiolabeled tracer for PET/CT scans. Therefore, animal litter, excrement and carcasses may contain radioactive materials. These materials pose risks to people and the environment.

　　 Anesthesia: Anesthetics are often used in animal experiments. Anesthetics are also harmful to human health. As an inhalation anesthetic, isoflurane has been widely used in animal experiments due to its excellent anesthetic quality. However, if workers come into contact with waste anesthetic gas, it may cause health problems. Safety issues caused by insufficient facilities and equipment: The main barriers include laboratory safety equipment, such as biological safety cabinets (BSC), animal isolators, and personal protective equipment (PPE). Workers are protected or isolated by the main barrier of pathogens, infectious materials and infected animals.

　　 Factors affecting the results of animal experiments: Animals themselves: Different animals have different characteristics in anatomy and pathophysiology. Different species react differently to the test material. The sex, age, weight, and physical health of the animal will also affect the results of the experiment. Healthy laboratory animals have better tolerance to various stimuli than unhealthy animals. Animal feeding environment and nutritional factors: Animal feeding environment factors including temperature, humidity, air exchange rate, air cleanliness, light, noise, etc. have an impact on the health of laboratory animals. If the animals involved in the experiment are malnourished, the results will be unreliable. The proficiency and technical procedures of the workers involved in laboratory animals. Key elements of ABSL-3 animal experiment management practices: training and experience of project team members; worker health and safety; animal carcasses and waste disposal; laboratory management practices; purchasing healthy laboratory animals from qualified laboratory animal suppliers ; Set up the quarantine and domestication period of experimental animals; scientific care of experimental animals; prevent the escape of infected animals; set up devices to prevent wild rodents from entering the facility; Safety management practices: safety management of pathogenic microorganisms; personnel access management; prevention of infectious aerosols; safe use of sharp objects; avoiding animal bites or scratches; formulating good standard operating procedures for animal experiments involving highly infectious drugs; Safe disposal of waste; emergency response; chemical safety management procedures; physical hazard safety management procedures; facility equipment management; personnel training.

　　 Conclusion: The management goal of the ABSL-3 laboratory is to ensure the safety of animal experiments with highly infectious drugs and obtain high-quality experimental data. In order to achieve this goal, we need to establish a comprehensive biosafety concept, which includes both overall consideration of safety (workers, environment) and data quality. These two aspects are critical to the successful implementation of animal experiments on ABSL-3. Comprehensive measures must be taken to do a good job in AUP review, laboratory animal management, laboratory safety management, facility equipment management, and personnel training. These measures can not only ensure the safety of ABSL-3, but also ensure the results of scientific animal experiments.