动物造模,金黄色葡萄球菌 z-bio 2021-11-26 420

　　OBJECTIVE: To study the inflammatory response in sterile rats with deep second-degree burns after infection by Staphylococcus aureus, and to establish models of deep second-degree burns in sterile rats and SPF rats and subsequent burn models. Each burn model of Staphylococcus aureus infection analyzes its healing process, inflammatory response and pathological changes.

　　 Method: 206-week-old female Wistar infertile rats were treated on a clean workbench with a constant temperature and pressure combustion device at 94°C for 8 seconds, causing 2 deep burns. Randomly divided into two groups. The wound infection concentration of one group was 1 x 108 CFU/mL Staphylococcus aureus 0.5 mL, and the other group was untreated, and the wound remained sterile. Twenty 6-week-old SPF Wistar female rats were cauterized under the same conditions and randomly grouped. The wound infection concentration of the two groups and one group was 1×108 CFU/mL. Staphylococcus aureus 0.5 mL, this group was not treated. Observe the wound nodule formation time, dementia time and healing time of the four groups of rats. Serum was collected before burn (0 hour), 24 hours, 48 hours, 3 days, 5 days, 7 days, 10 days and 14 days, and tumor necrosis factor-a was detected. (TNF-α), interleukin-1α (IL-1α) and epidermal growth factor receptor (ECFR) changes: HE staining of the skin, pathological changes observed at 24 hours, 34, 7 and 10 days after burns. Results: The burn healing and healing time of infertile rats infected with Staphylococcus aureus was significantly shorter than that of the other three groups (P\u003c0.05); SPF rats infected with Staphylococcus aureus appeared nodules, which contracted, tumors were removed and healed Significantly longer time (three) (P\u003c0.05); SPF burn rats infected with Staphylococcus aureus were double-damaged by the serum inflammatory factor TNF-α, and the level of IL-1α was significantly higher at 72 hours after the burn The other three groups (P\u003c0.05); the sterile rat serum responded strongly to burns and staphylococcal stimulation, and the levels of TNF-α, IL-1α and EGFR increased rapidly after burns, and were significantly higher in 24-hour burns Group 2. The serum EGFR level (P\u003c0.05) of rats at 48 hours of burn injury was significantly higher than that of the two groups of SPF rats (P\u003c0.05). Pathology showed that the time of angiogenesis and granulation tissue formation in SPF-infected rats with Staphylococcus aureus was longer than that of the other three groups; blood vessels in wounds of rats infected with Staphylococcus aureus aseptic burns were hemangiomas and granulation tissue formation time.

　　 Conclusion: Since the immune system of sterile rats is in a dormant state, they will be stimulated by burns and Staphylococcus aureus, thereby rapidly activating the systemic immune system and promoting wound healing. SPF burned rats were infected with Staphylococcus aureus. Various immune evasion molecules can intensify the body's inflammatory response and slow down wound healing.