动物造模,药效评价,肺炎 z-bio 2024-08-06 364

　　(1) The secretory Pseudomonas aeruginosa strain PAO1 and its variant strain PAOR were cultured overnight in tryptone soy broth at 37 ° C. After centrifugation, they were suspended in PBS (pH 7.4), washed by centrifugation, and the precipitate was suspended in an appropriate amount of PBS (pH 7.4). Add an appropriate amount of suspension to 2% agarose melted at 50 ℃ to prepare infected agarose beads with a final concentration of 10000000-100000 CFU/ml. Four week old SD rats were anesthetized with ketomine at a dose of 20mg/kg body weight via intraperitoneal injection. Ether was inhaled to alleviate pain, and then a small incision was made in the neck. 0.1ml agarose beads containing 1000000 or 10000000 CFU bacterial solution were injected into the rats via an air tube.

　　(2) In animal models of acute pneumonia caused by simple infection with Pseudomonas aeruginosa, the animals either die or the bacteria are cleared within 48 hours. Therefore, most animal models of pneumonia caused by acute or chronic Pseudomonas aeruginosa infection require encapsulating Pseudomonas aeruginosa in biofilms (agar, agarose, alginate) to prevent mechanical clearance of foreign objects by the trachea. This model uses Pseudomonas aeruginosa encapsulated in agarose, without the need for immunosuppressants or prior damage to the bronchi and lungs of the model animals, to obtain a typical Pseudomonas aeruginosa bronchopneumonia model. The method of making this model is simple, the results are reliable, and the repeatability is good.

　　(3) Comparative medical PA can be divided into two categories: mucinous and non mucinous, with mucinous PA having stronger pathogenicity. Therefore, there is a significant correlation between the severity of disease caused by model animal infection and the type of bacteria infecting the animal, and the amount of bacteria infected can also determine the severity of the disease. PA infected animals showed multifocal necrosis and inflammatory cell infiltration in the lungs; Inflammatory exudate can be seen surrounding small balls containing bacteria in adjacent tracheal walls, and sometimes peripheral bronchi may disappear; A large number of alveolar macrophages can be seen infiltrating the alveolar septa in the lung tissue surrounding the trachea, and phagocytosis of bacteria can also be observed in the macrophages. But after PAO1 infection in animals, acute pneumonia with parenchymal lesions such as vascular congestion and neutrophil infiltration appeared in the lungs, while after PAOR infection in animals, the lungs were mainly infiltrated by macrophages.