Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0009319 (colitis)
 19,384 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

There are four major categories of diarrheagenic Escherichia coli: enterotoxigenic (a major cause of travelers' diarrhea and infant diarrhea in less-developed countries), enteroinvasive (a cause of dysentery), enteropathogenic (an important cause of infant diarrhea), and enterohemorrhagic (a cause of hemorrhagic colitis and hemolytic uremic syndrome). Besides manifesting distinct clinical patterns, these categories of E. coli differ in their epidemiology and pathogenesis and in their O:H serotypes. Common features (albeit distinct for each category) include plasmid-encoded virulence properties, characteristic interactions with intestinal mucosa, and elaboration of various types of enterotoxins or cytotoxins. A less-well-defined fifth category of diarrheagenic E. coli is that of enteroadherent E. coli, so far identifiable only by their pattern of adherence to Hep-2 cells in tissue culture.
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PMID:Escherichia coli that cause diarrhea: enterotoxigenic, enteropathogenic, enteroinvasive, enterohemorrhagic, and enteroadherent. 354 52

Toxigenic Escherichia coli of human and animal origin have been classified into three categories: enterotoxigenic E. coli (ETEC), verotoxigenic E. coli (VTEC), and necrotoxigenic E. coli (NTEC), ETEC are a major cause of infant diarrhoea in less-developed countries and frequently cause colibacillosis in domestic animals. Human ETEC strains may synthesize LT-I and/or STa enterotoxins and they may possess the colonization factors CFA/I to CFA/IV; porcine strains synthesize LT-I, STa and/or STb, and possess the colonization antigens K88, P987, K99 or F41; and bovine strains are usually STa producers harbouring on the bacterial surface K99 or F41 colonization factors. There is a high host-specificity, because of that ETEC from animals are not pathogen for humans. VTEC strains may produce three mainly types of verotoxins (VT1, VT2, VT2vp1) that are functionally and structurally related to the shiga toxin. The VTEC of human and bovine origins produce VT1, VT2 or both, whereas VT2vp1 is elaborated by E. coli that cause edema disease in swine. The VTEC strains belonging mainly to serotypes O157:H7 or H-, O26:H11 and O111:H-, are now considered to be the major cause of two human syndromes of hitherto unknown cause: hemorrhagic colitis and hemolytic uremic syndrome. Most outbreaks of VTEC infection occurred in USA, Canada and United Kingdom during the last ten years and have been linked to consumption of undercooked ground beef, and, to a lesser extent, to the drinking of unpasteurized milk. Thus, the principal reservoir of VTEC is the intestinal tract of cattle. By contrast, it is presumed that human beings are the major reservoir of ETEC, and that contaminated water is a principal vehicle for transmission of ETEC infections. NTEC strains are able to elaborate two types of cytotoxic necrotizing factors (CNF1 and CNF2). Strains of human origin usually produce CNF1, whereas bovine NTEC generally synthesize CNF2. NTEC strains are not responsible for food-associated outbreaks of gastroenteritis, but CNF1 and CNF2 are very good markers of the source of food contamination.
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PMID:[Enterotoxigenic, verotoxigenic, and necrotoxigenic Escherichia coli in food and clinical samples. Role of animals as reservoirs of strains pathogenic for humans]. 754 50

Intimin is an important virulence factor in two groups of enteric pathogens: enteropathogenic Escherichia coli (EPEC), which is a major cause of infant diarrhea in the developing world, and enterohemorrhagic E. coli (EHEC), which has caused large food-borne outbreaks of hemorrhagic colitis in the United States and other developed countries. Intimin is encoded on a 35-kb pathogenicity island called the locus of enterocyte effacement (LEE). At least five antigenic types have been described for the highly variable gene, and each type is generally characteristic of particular evolutionary lineages. We determined the nucleotide sequences of intimin and other LEE genes in two O111 clones that have not been amenable to typing. The sequences from both O111:H8 and O111:H9 differed from the Int-beta that is typical of other clones in the same evolutionary lineage. The sequence from the O111:H8 strains was a mosaic of divergent segments that alternately clustered with Int-alpha, Int-beta, or Int-gamma. The sequence from the O111:H9 clone consistently showed a close relationship with that from E2348/69, a distantly related strain that expresses Int-alpha. The results suggest that there have been multiple acquisitions of the LEE in the EHEC 2/EPEC 2 clonal lineage, with a recent turnover in either O111:H8 or its close relatives. Amino acid substitutions that alter residue charge occurred more frequently than would be expected under random substitution in the extracellular domains of intimin, suggesting that diversifying selection has promoted divergence in this region of the protein. An N-terminal domain that presumably functions in the periplasm may also be under positive selection.
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PMID:Molecular evolution of the intimin gene in O111 clones of pathogenic Escherichia coli. 1175 25