I will finally make some points about the potential benefits to the host of a diarrheal response, based in part on some new studies we have initiated with another invasive pathogen, Salmonella typhi. This organism is very closely related to S typhimurium at the genetic level, yet causes a quite different clinical picture . Thus, while S typhimurium produces disease that is essentially limited to the gastrointestinal tract in normal individuals, with significant diarrhea, S typhi usually causes typhoid fever, a disease that is characterized by sepsis due to rapid bacterial dissemination to extraintestinal sites, but with little or no diarrhea . We have shown that, unlike S typhimurium, S typhi fails to elicit a delayed hypersecretory response in infected intestinal epithelial cells, and has qualitatively different effects on epithelial cell signaling.
We speculate, therefore, that the diarrheal response to S typhimurium may represent a protective adaptation that limits additional bacterial invasion. In the absence of such a response, as seen with S typhi, the host may be rendered susceptible to ongoing bacterial invasion followed by disseminated infection. Further studies, currently ongoing in our laboratory, will be required to confirm or refute our hypothesis. Nevertheless, the preliminary findings are intriguing in that they are consistent with the long-held, but unproven, view that diarrhea is beneficial to the host because it reduces the infectious load as well as the luminal concentration of toxins and other injurious agents. Before according universal enthusiasm for this primitive host defense mechanism and its benefits, we must ask ourselves which party stands to gain the most in the equation. The diarrheal response also represents a mechanism for spreading disease to additional individuals, to say nothing of the risk it represents to the initial victim in terms of dehydration and electrolyte imbalance. Thus, particularly in vulnerable hosts like young children, this ‘protection’ may come at too high a price. You finally have a choice and can find yourself a perfectly reliable pharmacy to shop with for best medications available: cialis professional 20 mg and see how quick and easy it could be to spend less money.