Studies On The Pathology Of KM Mice Infected With Porcine Circovirus Type 2 And Haemophilus Parasuis

To study the pathogenesis of coinfection and interaction between virus and bacteria,offer accurate method for differential diagnosis and early diagnosis,cut down economy missing caused by mixed infection.The experiments observed the pathological changes of KM mice in the system by intraperitoneal inoculation of porcine circovirus 2 and Haemophilus parasuis. This is for the the basis of establishes the pathological model of KM mice infected with porcine circovirus and Haemophilus parasuis.Screening the best medium of Haemophilus parasuis for animal experiments, successfully infected KM mice, and the LD50 was 3.4291×109 CFU by Bliss method.The KM mice were injected with different doses of PCV-2 virus solution, and set a blank control. Found that the mice injected with the virus have no significant clinical symptoms. We can see obvious and regular of pathological changes after the mice were killed.And the pathological changes of PCV-2 showed the Minimum amount of virus infection is the PCV-2 solution that the TCID50 was 106 diluted 100 times.The characteristic changes are lung hemorrhage, splenomegaly, swollen lymph nodes, liver focal necrosis, and apoptosis or necrosis in lymphocytes, macrophages of immune organs.The mice were injected with PCV-2 virus solution, then injected with different doses of Haemophilus parasuis after 7 days.Found that with the increasing dose of bacteria, their mortality. The resulting pathological changes also showed a more regular changes.HPS/PCV-2.mixed infection group, except for HPS infection alone appears pathological changes, but also appeared PCV-2 alone expressed in lymphocytes serious injury. So that Significantly increased the pathological changes in mice. Described above showed that mixed infection with two pathogens significant synergistic pathogenicity. Dead mice were more serious than mice survived,and Longer course of mice were more serious.