动物造模,肺炎链球菌肺炎模型 z-bio 2023-09-26 923

　　1. Modeling method: HMPV strain C-85473 was cultured with LLC-MK2, and female BALB/c mice were cultured with 1.5 × HMPV nasal drip infection with a dose of 100000 TCID50, followed by pneumococcal nasal drip infection with a dose of 1000 cfu after 5 days. The experiment was divided into three groups: individual infection with HMPV group, infection with inactivated hMPV and pneumococcal group, secondary infection with pneumococcal group after 5 days of infection with HMPV group, and infection with pneumococcal group after 14 days of infection with HMPV group. Observe the general condition of the animals every day, weigh them, and measure the airway obstruction in the mouse model. Animals were euthanized 6 days, 7 days, and 8 days after virus infection (corresponding to 1 day, 2 days, and 3 days after bacterial infection), and the viral and bacterial titers in lung tissue homogenate were measured, pathological changes were observed, and changes in cytokines were measured.

　　2. Results: After infection with HMPV virus, secondary pneumococcal infections caused significant weight loss, with an average decrease of 15% on the 8th day, accompanied by respiratory difficulties, erectile hair, and reduced movement; After 3 days of secondary bacterial infection, 100% of the animals died. Animals infected with viruses or bacteria alone have no obvious clinical symptoms or weight changes. The co infection group showed significant airway obstruction compared to the single infection group, but there was no significant change in virus titer. Compared with the group infected solely with bacteria, animals infected with pneumococcus after virus infection had an increase in bacterial count on the 8th day. The lung tissue of animals infected with HMPV alone showed mild lesions, which decreased over time from day 6 to day 8. The lung tissue of animals infected with pneumococcus alone showed no significant pathological changes, while the lesions of animals infected with pneumococcus after virus infection worsened over time, showing obvious inflammation and congestion. Compared to individual viral infections, there are 13 types of cytokines significantly increased in lung tissue.