耐甲氧西林金黄色葡萄球菌,小鼠模型 z-bo 2020-12-03 444

　　Objective: To use clinically isolated methicillin-resistant Staphylococcus aureus (MRSA) to infect ICR mice and establish a mouse model of MRSA systemic infection. Methods: After 3 consecutive days of intraperitoneal injection of cyclophosphamide (100 mg/kg) for immunosuppression, the MRSA bacterial solution with a concentration of 1×107 cfu/mL was inoculated into ICR mice through the tail vein. Survival analysis and peripheral blood leukocytes Count, tissue load and pathological examination to evaluate the model. Results: The mice began to die on the second day after MRSA inoculation, and the cumulative mortality rate reached 60% within 14 days; the total number of white blood cells in the peripheral blood increased significantly, and the bacteria colonized multiple organs. The bacterial load was kidneys and joints in descending order , Lung, liver, and brain, the kidneys contain up to 109 CFU/g, and the joints, lungs, liver, and brain contain 104~109 CFU/g. Pathological observation showed histopathological changes of multiple organ infections in kidney, heart, lung, liver, brain and joints.

　　Conclusion: The method of intravenous inoculation of MRSA after cyclophosphamide immunosuppression is the first successful establishment of a mouse model of MRSA systemic infection. This model can be applied to research fields such as MRSA pathogenesis and drug screening.