Experimental Study Of Pathophysiology In Invasive Pulmonary Aspergillosis Murine Model Immunosuppressed By Different Immunosuppressive Agents

[Objective] To compare the morbidity, mortality and patterns of infection in murine models after infected with aspergillus fumigatus.The murine models were immunosuppressed by different immunosuppressive agent that are normally used after renal tranplantation. [Methods] Forty male KM mice were randomly divided into four groups (n=10):group P, group F, group M and the control group, mice in group P were immunosuppressed with prednisone; mice in group F were immunosuppressed with tacrolimus; mice in group M were immunosuppressed with mycophenolate mofetil; the immunosuppressive agent was repalced by sterile saline in the control group. All mice were intranasally inoculated with a conidial suspension of Aspergillus fumigatus except the control group after 96 hours, mice in the control group were intranasally inoculated with sterile saline. Animals were observed after infection and weighed daily, mortality was recorded.96 hours after inoculation, survival mice were euthanized. Blood routine was examined. Lungs were removed after euthanization of the animals,20mg of the lung tissue was homogenized in sterile saline with sterile tissue grinders. Numbers of CFU were determined by performing the lung homogenate on 100-mm-diameter potato dextrose agar plates, and the infection rate was recorded. The rest of lung tissue were performed with pathological section to compare the patterns of infection. [Results] The weight of mice in group M and group F decreased obviously; mortality after inoculation: group P 0%, group F 37.5%, group M 62.5%, the control group 0%; infection rate:group P 22.2%, group F 50%, group M 75%, the control group 0%; infection rate was a little higher than mortality. Blood routine shows that the WBC level of the four group were of no significant difference. Numbers of CFU were of significant difference, group M had the most CFU, followed by group F and group P. Pathological section shows the primary pathological change of group M and group F is Intra-alveolar hemorrhage, the primary pathological change of group P is inflammatory necrosis. [Conclusion] Being exposured to high concentrations of Aspergillus fumigatus conidia, mice in group M had the highest morbidity and mortality of IPA. Its pathological change is charactered by Intra-alveolar hemorrhage.