The book discussed Multi Drug Resistant Salmonella at a molucular level and its inhabitant in various geographical regions. This study at molecular level on MDR Salmonella spp. may afford a promising therapy to control the emerged strains as well as it will prevent the further development of MDR in environment. As drug treatment may cause further development of MDR strains via genetic modification, molecular level approaches will be the best choice and more effective to control MDR stains. Apart from Salmonella spp. many pathogens develop MDR particularly, Staphylococcus aureus, Streptococcus and Enterococcus, Pseudomonas aeruginosa, Clostridium difficile, Klebsiella pneumoniae, Mycobacterium tuberculosis.Alterations in PhoP-PhoQ by proteomic approach and will lead to a better understanding of Salmonella pathogenesis and may lead to the development of safe, suitable vaccine development in future and also this mechanism at a molecular level provide promising tool in the treatment of enteric fever and also prevent further emerging of MDR Salmonella strains. Ultimately this report makes a start of deepness study of PhoP/q regulon.