Molecular mechanisms of Salmonella pathogenicity: Review

Abstract

Pathogenic Salmonella strains are cause disease in humans and many other mammalian species. Salmonella serotypes may cause a wide spectrum of diseases ranging from gastroenteritis, typhoid fever, bacteriemia, focal infections, to lifetime carrier state. These diseases are differ significantly from each other when considering their ethiology. However, similarities on basic molecular mechanisms of host-pathogen interactions have brought the Salmonella as a model microorganism to explain these interactions. Newer studies on the molecular pathogenesis of Salmonella enterica serotype typhimurium (S. typhimurium) induced enterocolitis in tissue culture models and the neonatal calf model have led to an improved to explaining of key events occurring during the complex series of host-pathogen interactions leading to diarrhea. On the other hand, latest epidemiological observations made among patients with AIDS in Africa, seem to support the concept that serotype S. typhi is able to evade adaptive immunity. In healthy individuals, nontyphoidal Salmonella serotypes are unable to overcome defense mechanisms that limit bacterial dissemination from the intestinal mucosa to systemic sites of infection. Advances in our understanding of the mechanisms by which nontyphoidal Salmonella serotypes cause gastroenteritis have helped us defining the unique properties that enable serotype Typhi to trigger host responses in humans leading to the development of typhoid fever rather than gastroenteritis. Especially, identification of genetic and biochemical basis of pathogen associated molecular patterns in Salmonella leads to explaining the biological process of infecton diseases. This review focuses on the new findings on molecular mechanisms of Salmonella pathogenicity. © 2010 by Türkiye Klinikleri.