Construction Of A Rat Model Of Complex Skin And Soft Tissue Infection

Objective:To establish a stable and reproducible rat model of complex skin and soft tissue infections,to explore the fluctuation of local tissue colony number,pathological changes and systemic state changes in rats after infection,so as to provide a complete animal model for the subsequent development of local antibacterial materials.Method:Experimental animals were divided into control group(normal saline),low concentration group(10~6CFU/ml),medium concentration group(10~8CFU/ml)and high concentration group(10~9CFU/ml).Use a weight of 200g to fall freely at a height of 80 cm,ca use stable local soft tissue damage to the right hind limb muscles of the rat,expose the damaged muscle tissue,and inoculate different concentrations of methicillin-resistant Staphylococcus aureus suspension.The rats were weighed on the 2nd,4th,6th,a nd 8th day after the operation,and local tissues were taken for colony counting and HE staining.Results:The control group had no symptoms of infection,and no colonies were detected in local tissues.In the low-concentration group,local tissue infectio n occurred on the 2nd and 4th day after the operation,and then the symptoms of infection subsided.No colonies were detected in the tissue on the 8th day,and the infection healed itself.Rats in the medium and high concentration group were seriously infe cted.On the 2nd and 4th day after the operation,the local soft tissue was partially necrotic and pus moss was attached.On the 6th and 8th day,the infection spread to the surrounding and deep tissues,the tissue necrosis was severe,and obvious purulent Change.Compared with the control group,the average body weight of the high-concentration group continued to decrease,and there was a significant difference,while there was no significant difference between the low-concentration and medium-concentratio n groups.Conclusion:A model of complex skin and soft tissue infection in SD rats has been successfully established.The modeling equipment of this model is simple and easy to obtain,the technical operation method is convenient,stable and repeatable,an d it is a complex skin and soft tissue infection model that can be widely promoted..When 100μl of 10~8CFU/ml bacterial suspension was inoculated,a stable skin and soft tissue infection of rat hind limbs could be formed,the number of local tissue colonie s was always greater than 10~8CFU/g,and obvious tissue necrosis and purulent changes could be observed by HE staining of muscle tissue.And it does not affect the general state of experimental animals...