Abstract:ObjectiveTo establish a stable and reliable mouse model of systemic infection induced by methicillin-resistant Staphylococcus aureus strain 252 (MRSA-252), and to provide reference and experimental foundation for the studies on pathogenesis of MRSA infection and development of MRSA vaccine. MethodsBased on the establishment of MRSA-252 OD600-CFU standard curve, BALB/c mice were infected with bacterial suspension via tail vein injection. Then we systematically evaluated the mouse model at different levels, including the selection of infection dose, the survival rate and change of body weight, bacterial number assay of blood samples and major organs, and the histopathological changes among different groups. ResultsThe lethal dose was 5.0×109 CFU/mouse and sublethal dose was 1.0×109 CFU/mouse, with a survival rate of 60%-70%. It showed a typical manifestation of systemic infection in the mice, including low survival rate, high bacterial load in blood and major organs, with a peak on the 3rd day after infection, and extensive histopathlogical changes including cell death and infiltration of inflammatory cells. ConclusionsA mouse model of systemic MRSA infection is successfully established. It provides a reliable technical support for efficacy study and safety evaluation of MRSA vaccines.
