Mycobacterium Avium Sub Species Paratuberculosis: Virulence Mechanism and Recent Vaccine Developments: A Review

Abstract

Misgana Bekele Daba

Mycobacterium avium subsp. Paratuberculosis (MAP) causes chronic inflammation of the intestine known as Johne’s disease in domestic and wild ruminants. This bacterium has also been linked to Crohn's disease, an inflammatory bowel illness in humans. Young animals are thought to be the most vulnerable to infection via oral uptake of the bacterium from a polluted environment. Following oral uptake, the bacterium can move through the intestinal wall to the basolateral side of the gut via the M cells. Following their discharge into the extracellular fluid of the lami- na propria, these bacteria are picked up by macrophages, which ordinarily digest bacteria by enzymatic activities. Mycobacterium paratuberculosis, on the other hand, is specialized in preventing phagosome-lysosome fusion, al- lowing it to survive inside macrophages. Furthermore, they send anti-apoptotic signals, allowing their host cell to live longer. By inhibiting IL-12, MAP is able to upregulate interleukin (IL)-10, an immunomodulatory cytokine that reduces macrophage destruction of MAP as well as Th1-type immune responses, which are most desirable to battle intracellular infections. New paratuberculosis vaccines are being developed using live attenuated vaccines or sub- units, usually recombinant MAP proteins that have been potentiated with adjuvants. Some Th1 antigens have been found by genomic and proteomic studies, including antigen 85 complex proteins (A, B, and C), superoxide dismutase, and heat shock protein 70 in cattle. However, Research on M. paratuberculosis is hindered by its slow growth rate and complex pathogenesis, leading to a lack of comprehensive information. Therefore, this review aims to provide an in-depth understanding of the pathogenesis of Mycobacterium paratuberculosis and explore recent developments in vaccines against this pathogen.

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