Mammalian cell entry operons; novel and major subset candidates for diagnostics with special reference to Mycobacterium avium subspecies paratuberculosis infection

摘要

Mammalian cell entry ( ) genes are the components of the operon and play a vital role in the entry of Mycobacteria into the mammalian cell and their survival within phagocytes and epithelial cells. operons are present in the DNA of Mycobacteria and translate proteins associated with the invasion and long-term existence of these pathogens in macrophages. The exact mechanism of action of genes and their functions are not clear yet. However, with the loss of these genes Mycobacteria lose their pathogenicity. subspecies (MAP), the etiological agent of Johne’s disease, is the cause of chronic enteritis of animals and significantly affects economic impact on the livestock industry. Since MAP is not inactivated during pasteurization, human population is continuously at the risk of getting exposed to MAP infection through consumption of dairy products. There is need for new candidate genes and/or proteins for developing improved diagnostic assays for the diagnosis of MAP infection and for the control of disease. Increasing evidences showed that expression of genes is important for the virulence of MAP. Whole-genome DNA microarray representing MAP revealed that there are 14 large sequence polymorphisms with LSPP12 being the most widely conserved MAP specific region that included a cluster of six homologs of -family involved in lipid metabolism. On the other hand, LSP11 comprising part of 2 operon was absent in MAP isolates. This review summarizes the advancement of research on genes of Mycobacteria with special reference to the MAP infection.