动物造模,感染性肺炎模型 z-bio 2022-10-20 359

　　Objective To establish an animal model of pneumonia caused by Staphylococcus aureus, Streptococcus pneumoniae and Escherichia coli, and to provide animal model support for efficacy evaluation.

　　Methods 36 SD rats, half male and half female, were randomly divided into blank control group, model control group and erythromycin group, with 12 rats in each group. After anesthesia in each group, the model control group and erythromycin group were given intratracheal instillation of 1 × 108CFU/mL mixed bacterial solution, 0.5 mL each, and the blank control group was infused with equal volume of normal saline. After 2 hours of modeling, oral and nasal inhalation was used for administration, 3 times a day, 10 minutes each time, with an interval of 4 hours, and continuous administration for 7 days. During the administration, observe the general state of rats in each group; On the 3rd and 7th day of modeling, the pulmonary function of rats was checked, the number of leukocytes and the percentage of neutrophils in alveolar lavage fluid (BALF) were measured, and interleukin-6 (IL-6) and tumor necrosis factor (TNF) in BALF were detected by ELISA- α (TNF- α), HE staining was used to observe the pathological changes of lung tissue, and the bacterial culture of lung tissue was counted.

　　Results Compared with the blank control group, the body temperature, white blood cell (WBC), neutrophil count (Neu%) and TNF in the model control group- α、 IL-6 was significantly increased, forced vital capacity (FVC), forced expiratory volume to forced vital capacity (FEV200/FVC), and tidal volume (VT) were significantly reduced, the alveolar structure of rats was damaged, a large number of inflammatory cells infiltrated, and the pulmonary interstitium was thickened; Compared with the model control group, temperature, WBC, Neu%, TNF in erythromycin group- α、 IL-6 decreased significantly, FVC, FEV200/FVC, VT increased significantly, pathological changes of lung tissue in rats decreased significantly, and the number of Staphylococcus aureus, Streptococcus pneumoniae, and Escherichia coli in lung tissue decreased significantly.

　　Conclusion In this experiment, the mixed bacteria of Staphylococcus aureus, Streptococcus pneumoniae and Escherichia coli were used to drip into the lungs of rats through air tubes to establish a bacterial infectious pneumonia model, which can be used to evaluate the efficacy.