Pigs as an experimental model for systemic Mycobacterium avium infectious disease

Mycobacterium avium complex (MAC) is an opportunistic pathogen in AIDS patients and pigs, and causes dissemination through primary intestinal lesions. However, its pathogenesis is not well understood. In this article, we hypothesize that pigs can provide a suitable experimental model of disseminated MAC disease. We compared the initial route of infection, the characteristics of the pathogenic strains, the immunological status of the hosts, and the histological characteristics. The route of infection and infective strains are similar in AIDS patients and pigs. Pigs can respond to infection by the formation of systemic epithelioid granuloma with sufficient cell-mediated immunity. However, there are differences in immunological status and histological features between AIDS patients and pigs. Therefore, pigs might be used as an appropriate animal model because of their good cell mediated immunity triggered by systemic mycobacterial infection. In conclusion, MAC infections in AIDS patients and pigs show similarities in terms of the initial route of infection and the genetic characteristics of the pathogenic strains.