Mycobacterium avium complex infection in pigs: A review

The Mycobacterium avium complex – an underestimated threat to humans and animals

“…This interaction leads to phagocytosis and the release of reactive metabolites, resulting in the initiation of intracellular signaling and the release of cytokines and MACs employ several mechanisms to survive in adverse conditions inside macrophages: they produce agents that inhibit the mechanisms associated with an oxidative burst (e.g. superoxide dismutase or heat shock proteins), or inhibit the fusion of phagosome and lysosome [42]. The recognition of MAC by macrophages mainly acts through toll-like receptor 2 (TLR2) [43]; this leads to the production of pro-inflammatory cytokines, such as interleukins IL-1β, IL-12, IL-18, tumour necrosis factor α (TNFα), as well as chemokines such as the C-X-C motif chemokine 10 (CXCL-10) [42].…”

“…superoxide dismutase or heat shock proteins), or inhibit the fusion of phagosome and lysosome [42]. The recognition of MAC by macrophages mainly acts through toll-like receptor 2 (TLR2) [43]; this leads to the production of pro-inflammatory cytokines, such as interleukins IL-1β, IL-12, IL-18, tumour necrosis factor α (TNFα), as well as chemokines such as the C-X-C motif chemokine 10 (CXCL-10) [42]. Chemokines and TNFα cause taxis of inflammatory cells such as lymphocytes, macrophages and dendritic cells, to the inflammation site.…”

“…The activated macrophages, together with the living mycobacteria, migrate to lymph nodes; here, the antigen is presented to T helper cells by the major histo-compatibility complex class II (MHC II). This mechanism induces a specific immune response in the host [42]. The ability of macrophages to kill mycobacteria is enhanced by the presence of Th1 lymphocytes, which secrete IFN-γ and IL-2.…”

“…The ability of macrophages to kill mycobacteria is enhanced by the presence of Th1 lymphocytes, which secrete IFN-γ and IL-2. In addition, mycobacteria can also be recognized by the MHC II independent pathway thanks to cluster of differentiation 1 (CD1) [42]. Such recognition is specific to γδT lymphocytes, which are highly reactive towards mycobacteria and capable of killing them [42].…”

“…Pathogenesis and clinical signs in animals. MAC bacteria are also known to cause disease in many animal species, such as dogs [55], cats [56], pigs [42], cattle [57], horses [12] and birds [58]. MAC infections are rarely diagnosed in dogs,; however, the presence of the disease is generally regarded to be associated with immunodeficiency.…”