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 species represent a leading cause of gastroenteritis worldwide. More recently, they have been proposed as putative vaccine delivery vehicles in humans. Oral infection with Salmonella leads to invasion of the intestinal epithelial barrier and subsequent interaction with mucosal macrophages. In this study, we investigated the fate of Salmonella typhimurium-infected human macrophages differentiated from blood monocytes by GM-CSF. Wild type S. typhimurium strain SL1344 induced macrophage surface blebbing and caused the release of host cytoplasmic lactate dehydrogenase beginning 30 min post-infection. Three hours later more than 80% of the macrophages in the culture were killed. In contrast, during the same period, macrophages infected with the non-invasive S. typhimurium strain BJ66 remained viable. Chromatin fragmentation is a hallmark of cells undergoing apoptosis. Using TUNEL analysis, we observed chromatin fragmentation in macrophages infected with SL1344 but not in BJ66 infected cells. Consistent with this observation, we found that pretreatment of human macrophages with an inhibitor of caspase-3, a member of the pro-apoptotic enzyme family shown to be involved in S. typhimurium-induced killing of mouse macrophages, reduced SL1344-mediated cytotoxicity by 40%. Our study provides the first evidence that invasive S. typhimurium induces apoptosis in human macrophages that were differentiated from blood monocytes by GM-CSF, and that cell death is a caspase-dependent phenomenon.
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PMID:Salmonella typhimurium induces apoptosis in human monocyte-derived macrophages. 1122 Jun 87

Several species of Vibrio are the causative agent of gastroenteritis in humans. In aquaculture, Vibrio harveyi (Vh) and V. parahaemolyticus (Vp) have long been considered as shrimp pathogens in freshwater, brackish and marine environments. Here we show by using scanning electron microscopy (SEM) that Penaeus monodon orally inoculated with each of these two pathogens via an Artemia diet had numerous bacteria attached randomly across the stomach surface, in single and in large biofilm-like clusters 6 h post-infection. A subsequent marked proliferation in the number of V. harveyi within the biofilm-like formations resulted in the development of infections in the stomach, the upper and middle midgut, but neither in the posterior midgut nor the hindgut. SEM also revealed the induced production of peritrichous pili-like structures by the Vp attaching to the stomach lining, whilst only a single polar fibre was seen forming an apparent physical bridge between Vh and the host's epithelium. In contrast to these observations, no such adherences or linkages were seen when trials were conducted with non-pathogenic Vibrio spp. or with Micrococcus luteus, with no obvious resultant changes to the host's gut surface. In naive shrimp, the hindgut was found to be a favorable site for bacteria notably curved, short-rod shaped bacteria which probably belong to Vibrio spp. Data from the current study suggests that pathogens of P. monodon must be able to colonize the digestive tract, particularly the stomach, where chitin is present, and then they use an array of virulent factors and enzymes to infect their host resulting in disease. Oral infection is a better way of mimicking natural routes of infection; investigating the host-bacteria interactions occurring in the digestive tract may lead to new strategies for the prevention or control of bacterial infections in penaeids.
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PMID:Interaction of Vibrio spp. with the Inner Surface of the Digestive Tract of Penaeus monodon. 2628 30