Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0017160 (gastroenteritis)
 11,398 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Salmonella causes a wide range of diseases from acute gastroenteritis to systemic typhoid fever, depending on the host. To invade non-phagocytic cells, Salmonella has developed different mechanisms. The main invasion system requires a type III secretion system (T3SS) known as T3SS-1, which promotes a Trigger entry mechanism. However, other invasion factors have recently been described in Salmonella, including Rck and PagN, which were not expressed under our bacterial culture conditions. Based on these observations, we used adhesion and invasion assays to analyse the respective roles of Salmonella Enteritidis T3SS-1-dependent and -independent invasion processes at different times of infection. Diverse cell lines and cell types were tested, including endothelial, epithelial and fibroblast cells. We demonstrated that cell susceptibility to the T3SS-1-independent entry differs by a factor of nine between the most and the least permissive cell lines tested. In addition, using scanning electron and confocal microscopy, we showed that T3SS-1-independent entry into cells was characterized by a Trigger-like alteration, as for the T3SS-1-dependent entry, and also by Zipper-like cellular alteration. Our results demonstrate for what is believed to be the first time that Salmonella can induce Trigger-like entry independently of T3SS-1 and can induce Zipper-like entry independently of Rck. Overall, these data open new avenues for discovering new invasion mechanisms in Salmonella.
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PMID:Heterogeneity of type III secretion system (T3SS)-1-independent entry mechanisms used by Salmonella Enteritidis to invade different cell types. 2110 65

The Salmonella enterica species includes about 2600 diverse serotypes, most of which cause a wide range of food- and water-borne diseases ranging from self-limiting gastroenteritis to typhoid fever in both humans and animals. Moreover, some serotypes are restricted to a few animal species, whereas other serotypes are able to infect plants as well as cold- and warm-blooded animals. An essential feature of the pathogenicity of Salmonella is its capacity to cross a number of barriers requiring invasion of a large variety of phagocytic and nonphagocytic cells. The aim of this review is to describe the different entry pathways used by Salmonella serotypes to enter different nonphagocytic cell types. Until recently, it was accepted that Salmonella invasion of eukaryotic cells required only the type III secretion system (T3SS) encoded by the Salmonella pathogenicity island-1. However, recent evidence shows that Salmonella can cause infection in a T3SS-1-independent manner. Currently, two outer membrane proteins Rck and PagN have been clearly identified as Salmonella invasins. As Rck mediates a Zipper-like entry mechanism, Salmonella is therefore the first bacterium shown to be able to induce both Zipper and Trigger mechanisms to invade host cells. In addition to these known entry pathways, recent data have shown that unknown entry routes could be used according to the serotype, the host and the cell type considered, inducing either Zipper-like or Trigger-like entry processes. The new paradigm presented here should change our classic view of Salmonella pathogenicity. It could also modify our understanding of the mechanisms leading to the different Salmonella-induced diseases and to Salmonella-host specificity.
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PMID:Multiplicity of Salmonella entry mechanisms, a new paradigm for Salmonella pathogenesis. 2317 Feb 25