动物造模 z-bio 2022-08-05 493

　　Objective To establish a mixed bacterial infection pneumonia model of Staphylococcus aureus, Streptococcus pneumoniae and Escherichia coli, and provide animal model support for drug efficacy evaluation.

　　Methods Thirty-six SD rats, half male and half male, 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 instilled with 1 × 108 CFU/mL mixed bacterial solution, 0.5 mL each, and the blank control group was instilled with an equal volume of normal saline. Two hours after the modeling, oral and nasal inhalation was administered, 3 times a day, 10 min each time, with an interval of 4 hours between each time, and the drug was administered continuously for 7 days. During the administration period, the general state of the rats in each group was observed; on the 3rd and 7th day of modeling, the lung function of the rats was examined, the number of white blood cells and the percentage of neutrophils in bronchoalveolar lavage fluid (BALF) were determined, and BALF was detected by ELISA. Interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), HE staining was used to observe the pathological changes of lung tissue, and bacterial culture was counted in lung tissue.

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

　　Conclusion In this experiment, the mixed bacteria of Staphylococcus aureus, Streptococcus pneumoniae, and Escherichia coli were used to instill in the lungs of rats through trachea to establish a bacterial infection pneumonia model successfully, which can be used to evaluate the efficacy of the drug.