Establishment Of Infection Model Of Actinobacillus Pleuropneumoniae Mice And Its Distribution In Vivo

Porcine Contagious Pleuropneumonia (PCP) is a highly contagious and lethal swinerespiratory infectious disease caused by Actinobacillus pleuropneumoniae (APP). In recent years,this disease has been commonly found in nursery pigs which are raised in large scale farms inmost districts of china. There have been fifteen serotypes for APP, the main popular serotypesare serotype1, serotype3, serotype5and serotype7in our country, the pathogenic mechanismof this disease is not clear, in order to reveal the pathology changes of various organizations andvisceral organs after pathogen infection and the rules of transitional distribution in vivo, thisexperiment plans to establish the animal model of Actinobacillus pleuropneumoniae disease.Experiment uses Actinobacillus pleuropneumoniae7strain, through artificial means of infectionin experimental animals, explore their susceptibility and the best way to experimental animals.The immunohistochemistry method is used to detect infection in animals and its transitionaldistribution in the model animals.Experimental results show that the APP-7type strain has strong pathogenicity to mice. Theresults indicated that obvious clinical symptoms have observed in mice and the median lethaldose (LD50) was6.7×107CFU. And found that the best way of infection was intraperitonealinjection. By observing the clinical symptoms of mice which were infected, pathological changesof various tissues and organs and mortality and so on. We found that these characteristics have ahighly similarity with the performance of porcine which infected with APP, and ascertained thatmice are suitable for an ideal animal model of the APP infected test. The results ofImmunohistochemical showed that there existed bacterial in lungs after2hours of bacterialinfection in mice, there existed bacterial in spleens4hours after infection. With the extension ofthe infection time, in the main tissue of mice liver, kidney, heart and other organs have beenmonitoring to the distribution of bacteria. In addition, the strains separated from organizationwas identified and found that was consistent with infection strains.This study successful established APP-7animal models of mice through the infection andconfirmed that the distribution of the bacterial in major organs of mice in different time ofinfection. In addition, revealed the association of distribution of bacteria with tissue damage. Itbuilt a solid foundation for exploring the pathogenesis of porcine pleuropneumonia infection, vaccine development in later period and scientific prevention for PCP.