动物造模 z-bio 2022-10-13 331

　　Objective To explore the inflammatory response of sterile rats after deep second-degree scald wounds were infected with Staphylococcus aureus, the test used sterile rats and SPF rats to establish deep second-degree scald models and post-scald Staphylococcus aureus infection respectively. 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 scalding apparatus at 94°C for 8 s to cause deep second-degree burns in the ultra-clean workbench. They were randomly divided into two groups, and the wound infection concentration of one group was 1 ×108CFU/mL Staphylococcus aureus 0.5mL, one group was left untreated, and the wounds were kept 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 was 0.5 mL, and one group was not treated. The wound nodulation time, demagnification time and healing time of the four groups of rats were observed respectively, and serum was collected before scald (0h), 24h, 48h, 3d, 5d, 7d, 10d, and 14d after scald, and tumor necrosis factor was detected. Changes of -a (TNF-α), interleukin-1α (IL-1α) and epidermal growth factor receptor (ECFR): HE staining of the wounds at 24h, 34, 7d, and 10d after scalding to observe the pathological changes.

　　Results The wound shedding and healing time of the sterile rats infected with Staphylococcus aureus were significantly shorter than those of the other three groups (P<0.05). group (P<0.05); the SPF scalded rat group infected with Staphylococcus aureus increased the levels of serum inflammatory factors TNF-α and IL-1α due to double injury, and the levels were significantly higher than those of the other three groups at 72 h after scalding (P <0.05)); due to the intense reaction of germ-free rats to scald and Staphylococcus aureus stimulation, the serum levels of TNF-α, IL-1α and EGFR increased rapidly after scalding, and at 24 h after scalding, the levels of SPF were significantly higher than those in the two groups. The level of serum EGFR was significantly higher than that of the two groups of SPF rats (P<0.05) at 48h after scalding in rats (P<0.05). Pathology showed that the formation time of new blood vessels and granulation tissue in the wound of SPF scalded rats infected with Staphylococcus aureus was longer than that of the other three groups; the formation time of new blood vessels and granulation tissue in the wound of rats infected with Staphylococcus aureus aseptic scalded was shorter than that of other groups. 3 sets.

　　Conclusion Because the immune system of germ-free rats is in a dormant state, they are stimulated by both scald and Staphylococcus aureus, which rapidly activates their systemic immune system and accelerates wound healing. Immune evasion molecules aggravate the body's inflammatory response and delay wound healing.