Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023241 (Legionella)
 6,990 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Shigella infection, the cause of bacillary dysentery, induces caspase-1 activation and cell death in macrophages, but the precise mechanisms of this activation remain poorly understood. We demonstrate here that caspase-1 activation and IL-1beta processing induced by Shigella are mediated through Ipaf, a cytosolic pattern-recognition receptor of the nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family, and the adaptor protein apoptosis-associated speck-like protein containing a C-terminal caspase recruitment domain (ASC). We also show that Ipaf was critical for pyroptosis, a specialized form of caspase-1-dependent cell death induced in macrophages by bacterial infection, whereas ASC was dispensable. Unlike that observed in Salmonella and Legionella, caspase-1 activation induced by Shigella infection was independent of flagellin. Notably, infection of macrophages with Shigella induced autophagy, which was dramatically increased by the absence of caspase-1 or Ipaf, but not ASC. Autophagy induced by Shigella required an intact bacterial type III secretion system but not VirG protein, a bacterial factor required for autophagy in epithelial-infected cells. Treatment of macrophages with 3-methyladenine, an inhibitor of autophagy, enhanced pyroptosis induced by Shigella infection, suggesting that autophagy protects infected macrophages from pyroptosis. Thus, Ipaf plays a critical role in caspase-1 activation induced by Shigella independently of flagellin. Furthermore, the absence of Ipaf or caspase-1, but not ASC, regulates pyroptosis and the induction of autophagy in Shigella-infected macrophages, providing a novel function for NLR proteins in bacterial-host interactions.
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PMID:Differential regulation of caspase-1 activation, pyroptosis, and autophagy via Ipaf and ASC in Shigella-infected macrophages. 1769 8

Despite considerable advances in drinking water safety assurance and adherence to the public health standards, waterborne diaseases outbreaks have still been observed even in industrialized countries. The study objective was to map such outbreaks in the Czech Republic in 1995-2005. In this study, an outbreak is the occurrence of more cases of disease than normally expected within a specific place over a given period of time and a waterborne disease is a disease where water is the vehicle or source of infection. The data on waterborne outbreaks was obtained from the EPIDAT database (national infectious diseases reporting system) information provided by epidemiologists of all regional public health authorities and the National Reference Laboratory for Legionella. In 1995 - 2005, 33 outbreaks with water indicated as the route of transmission were recorded in the Czech Republic. The leading cause was unsafe drinking water (27 outbreaks), mainly from wells (19 outbreaks); nevertheless, the most serious consequences were observed in two outbreaks caused by microbiologically contaminated hot water. Other sources of waterborne infection were mineral water springs, a swimming pool and a brook. The total of reported cases of waterborne diseases was 1655, 356 hospitalisations and ten deaths due to legionellosis were recorded. The highest number of outbreaks (7) as well as the highest number of cases (841) were reported in 1997. Comparison of two five-year periods, i.e. 1996-2000 and 2001-2005, showed a nearly one third decrease in the total of outbreaks and a half reduction in the total of cases in the latter. In view of the limited length of monitoring, it is not possible to say with certainty whether it is a random distribution or an actual trend. Almost two thirds of cases were diagnosed as acute gastroenteritis of probable infectious origin and other frequent waterborne diseases were viral hepatitis A and bacillary dysentery. When analyzing the described outbreaks, it should be taken into account that only the diagnosed and reported outbreak cases are covered, while the actual number of cases is likely to be underreported. Although no evidence is available that any vast and serious waterborne diseases outbreaks escaped reporting, some small and less serious outbreaks may have occurred unnoticed. In the future, the diagnosis, investigation and evaluation of waterborne diseases outbreaks should be improved, among others by implementing an evidence-based classification system and issuing regular surveys of outbreaks and their causes which would be helpful in preventing failures in other similar water sources.
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PMID:[Waterborne diseases outbreaks in the Czech Republic, 1995-2005]. 1975 Aug 23