动物造模 z-bio 2021-09-06 605

　　Objective To explore the inflammatory response of the body after deep second-degree scald wounds in sterile rats were infected with Staphylococcus aureus, and to test the use of sterile rats and SPF rats to establish deep second-degree scald models and post-scalded Staphylococcus aureus infections. Model to analyze the healing process, inflammatory response and pathological changes.

　　Methods Twenty 6-week-old female Wistar sterile rats were treated with a constant temperature and pressure scald instrument at 94°C for 8 seconds in a clean workbench to cause deep second-degree scalds. They were randomly divided into two groups, one group had a wound infection concentration of 1 ×108CFU/mL Staphylococcus aureus 0.5mL, one group is left untreated, and the wound remains sterile; 20 6-week-old female SPF Wistar rats, scalded under the same conditions, were randomly divided into two groups, one group of wounds The infection concentration was 1×108 CFU/mL. Staphylococcus aureus 0.5 mL, and one group was not treated. Observe the wound nodulation time, dementia time and healing time of the 4 groups of rats. Serum was taken before scald (0h), 24h, 48h, 3d, 5d, 7d, 10d, 14d after scald, and detected tumor necrosis factor -a (TNF-α), interleukin-1α (IL-1α) and epidermal growth factor receptor (ECFR) changes: HE staining of the skin at 24h, 34, 7 and 10 days after scald, observe the pathological changes.

　　Results Aseptic rats infected with Staphylococcus aureus had significantly shorter wound healing and healing time than the other three groups (P<0.05); SPF rats infected with Staphylococcus aureus had significantly longer nodulation, detumescence and healing time than the other 3 groups. Group (P<0.05); the level of serum inflammatory factors TNF-α and IL-1α increased in the SPF-grade scalded rat group infected with Staphylococcus aureus due to double injury, and was significantly higher than the other three groups at 72h after the scald (P <0.05)); As the sterile rats reacted fiercely to scald and Staphylococcus aureus stimulation, serum TNF-α, IL-1α and EGFR levels increased rapidly after scald, and were significantly higher than the SPF of the two groups at 24 hours of scald In mice (P<0.05), the serum EGFR level was significantly higher than the two groups of SPF rats (P<0.05) at 48h of burn. Pathology showed that the time of neovascularization and granulation tissue formation in the wound of rats infected with Staphylococcus aureus SPF was longer than that of the other three groups; the time of formation of neovascularization and granulation tissue in the wound of rats infected with Staphylococcus aureus aseptic scald was shorter than other groups. 3 groups.

　　Conclusion Because the immune system of sterile rats is in a dormant state, it is stimulated by scalds and Staphylococcus aureus, which quickly activates its systemic immune system and accelerates wound healing; SPF scalded rats are infected with Staphylococcus aureus and produce a variety of Immune evasion molecules aggravate the body's inflammatory response and delay wound healing.