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

We analyzed Escherichia coli O157:H7 isolates from stool samples of five patients who had bloody diarrhea and were infected during a large food-borne outbreak of hemorrhagic colitis in Washington state. The isolates were assessed for Shiga-like toxin profile, adherence and plasmid traits, mouse virulence, capsule, and enterohemolysin production. The profiles of the five isolates were indistinguishable from each other and similar to that of E. coli O157:H7 strain EDL933, an organism responsible for a similar hamburger-associated food poisoning episode in 1982.
 ...
PMID:Profile of Escherichia coli O157:H7 pathogen responsible for hamburger-borne outbreak of hemorrhagic colitis and hemolytic uremic syndrome in Washington. 825 89

Gnotobiotic pigs were used as a model to study the contribution of Shiga-like toxin I to natural disease caused by enterohemorrhagic Escherichia coli in calves and human beings. Eleven 2- to 7-day-old gnotobiotic pigs of either sex, obtained by closed hysterotomy, were injected intramuscularly with graded doses of partially purified Shiga-like toxin I derived from a lysogenized Escherichia coli strain. Four other gnotobiotic pigs were injected with a mock toxin preparation obtained from a nonlysogenized culture of the same E. coli strain. All toxin-injected pigs developed diarrhea, and three displayed signs of neurologic disease. Pigs either died or were euthanatized 2 to 4 days post-inoculation. Necrosis of muscle was grossly evident at the site of injection in all toxin-inoculated pigs. Hemorrhage in the lumen of the small and large intestines and blood in the feces were also evident in two toxin-inoculated pigs. Microscopically, severe necrotizing myositis at the injection site, multifocal encephalomalacia, and mucosal infarcts and hemorrhage in the small and large intestines were seen. In small vessels at lesion sites, endothelial cells were frequently swollen or necrotic. Pigs inoculated with mock toxin did not develop diarrhea or exhibit signs of neurologic disease, and the only apparent lesion was mild microscopic myositis at the injection site in 1/4 pigs. The results of this study indicate that Shiga-like toxin I causes vascular damage and ischemic necrosis in the intestines and brains of gnotobiotic pigs. These lesions are similar to those seen in the intestines of calves and human beings with hemorrhagic colitis and in the brains of human beings with thrombotic thrombocytopenic purpura.
 ...
PMID:Clinical signs and lesions in gnotobiotic pigs inoculated with Shiga-like toxin I from Escherichia coli. 826 23

The majority of cases of hemolytic-uremic syndrome and a smaller proportion of cases of thrombotic thrombocytopenic purpura have recently been shown to result from a toxin produced by enteric bacteria, referred to as verotoxin, or Shiga-like toxin. The predominant toxin-producing bacterial strain in North America is E. coli O157:H7, which causes hemorrhagic colitis in humans after ingestion of contaminated meat. The toxin is believed to gain entry to the circulation from the bowel wall; it then binds to specific glycolipid receptors abundant on renal vascular endothelial cells. The toxin inactivates ribosomes inside the cells, thereby killing them and producing the clinical manifestations of hemolytic-uremic syndrome. Recognition of the etiology of hemolytic-uremic syndrome may lead to better prospects for prevention and treatment.
 ...
PMID:Southwestern Internal Medicine Conference: Shiga-like toxins in hemolytic-uremic syndrome and thrombotic thrombocytopenic purpura. 826 83

Escherichia coli K-12 strains producing high levels of Shiga-like toxin type II (SLT-II) but not SLT-I were previously shown to be virulent in an orally infected, streptomycin-treated mouse model. In this investigation, we tested the virulence of several SLT-II-producing enterohemorrhagic E. coli (EHEC) isolates from patients with hemorrhagic colitis or hemolytic uremic syndrome. All of the strains tested were able to colonize the mouse intestine. However, only two strains were consistently virulent for mice: O91:H21 strain B2F1 (Strr), which was previously shown to carry two copies of slt-II-related toxins, and O91:H21 strain H414-36/89 (Strr), which was found in this study to contain three genes from the slt-II group. The oral 50% lethal doses of strains B2F1 (Strr) and H414-36/89 (Strr) when fed to streptomycin-treated mice were less than 10 bacteria. Histological sections from moribund mice fed the O91:H21 strains demonstrated extensive renal tubular necrosis; however, hematological results were not consistent with a diagnosis of hemolytic uremic syndrome. The central role of SLT in the virulence of the O91:H21 EHEC strains was supported by the finding that streptomycin-treated mice preinoculated with monoclonal antibody specific for SLT-II survived oral challenge with either B2F1 (Strr) or H414-36/89 (Strr). The basis for the variation in virulence among the SLT-II-producing EHEC strains tested was not determined. However, a correlation between the capacity of an EHEC strain to grow in small intestinal mucus and lethality in the streptomycin-treated mice was observed.
 ...
PMID:Virulence of enterohemorrhagic Escherichia coli O91:H21 clinical isolates in an orally infected mouse model. 835 4

Serum interleukin 6 (IL-6) and tumour necrosis factor (TNF) were measured in children with dysentery during an epidemic caused by Shigella dysenteriae 1. IL-6 and TNF were also measured in fresh stool filtrates from children with acute gastroenteritis. The median serum IL-6 concentration was raised significantly in the children with complications (haemolytic uraemic syndrome, leukemoid reaction, thrombocytopenia, thrombocytosis, and severe colitis lasting more than one week) during the first week (n = 18, 9-7728 pg/ml; median 107) and in the second week (n = 13, 5-312 pg/ml; median 77), compared with convalescent sera (n = 10, < 3-85 pg/ml; median 39; p < 0.02 and < 0.05 respectively). The median IL-6 concentration during the first week was significantly higher in the group with complicated disease than in those with no complications (n = 8, < 3-37 pg/ml; median 5; p < 0.001). Although serum TNF concentrations were significantly raised in the complicated group during the first and second weeks of the illness and in the uncomplicated group compared with convalescence, there was no significant difference in the TNF concentrations between the complicated and uncomplicated groups. IL-6 was detectable in stool filtrates from eight of 13 children with S dysenteriae 1 infection and four of eight children with S flexneri infection. It was not detectable in Cryptosporidia, rotavirus, or adenovirus infections, those with pathogen-negative acute diarrhoea or controls. Seven of 13 children with S dysenteriae 1 and three of nine children with S flexneri infections had TNF detectable in stools. None of the children with Salmonella, Cryptosporidia, rotavirus of children with pathogen-negative diarrhoea and controls had detectable TNF in stool filtrates. It is postulated that the local and generalised vasculitis observed in shigellosis may be related to a direct effect of Shiga toxin on endothelial cells or caused by cytokine production stimulated by endotoxin, or both.
 ...
PMID:Concentrations of interleukin 6 and tumour necrosis factor in serum and stools of children with Shigella dysenteriae 1 infection. 830 92

Shiga-like toxin (SLT)-producing Escherichia coli (SLTEC) O101 has recently been associated with hemorrhagic colitis and hemolytic-uremic syndrome in humans. In this study, SLTEC O101 strains from humans and pigs were characterized for clonal relatedness by nucleotide sequence analysis of their slt genes, DNA finger-printing of genomic DNA, and determination of virulence factors. The slt genes of five E. coli O101 strains were cloned and sequenced. For all strains, the deduced amino acid sequences of the B subunits were identical to those of the SLT-IIe present in the classical SLTEC O139 strains that cause edema disease in pigs. The A subunit revealed more than 99% homology to that of SLT-IIe. DNA fingerprinting revealed a high degree of genetic relatedness between the human and porcine O101 isolates. None of the O101 strains investigated had virulence factors frequently found in porcine (F107 fimbriae or heat-stable or heat-labile enterotoxins) or human SLTEC strains (eaeA or enterohemorrhagic E. coli hemolysin). The absence of virulence factors typical of SLT-I- and SLT-II-producing E. Coli together with the presence of SLT-IIe, a toxin previously seen only in porcine E. coli, suggests a new pathogenic mechanism for E. coli O101 infection of humans. For diagnostic purposes, we recommend the use of PCR primers and DNA probes complementary to slt-IIe to correctly identify such strains and to further evaluate their role in human diseases.
 ...
PMID:Clonal relatedness of Shiga-like toxin-producing Escherichia coli O101 strains of human and porcine origin. 858 96

Shiga-like toxin-producing Escherichia coli (SLTEC) strains are a diverse group of organisms which are known to cause diarrhea and hemorrhagic colitis in humans. This can lead to potentially fatal systemic sequelae, such as hemolytic-uremic syndrome (HUS). Strains belonging to more than 100 different O:H serotypes have been associated with severe SLTEC disease in humans, of which only O157 strains (which are uncommon in Australia) have a distinguishable cultural characteristic (sorbitol negative). During an outbreak of HUS in Adelaide, South Australia, a sensitive PCR assay specific for Shiga-like toxin genes (slt) was used to test cultures of feces and suspected foods. This enabled rapid confirmation of infection and identified a locally produced dry fermented sausage (mettwurst) as the source of infection. Cultures of feces from 19 of 21 HUS patients and 7 of 8 mettwurst samples collected from their homes were PCR positive for slt-I and slt-II genes. SLTEC isolates belonging to serotype O111:H- was subsequently isolated from 16 patients and 4 mettwurst samples. Subsequent restriction fragment length polymorphism analysis of chromosomal DNA from these isolates with slt-specific probes indicated that at least three different O111:H- genotypes were associated with the outbreak. Pulsed-field gel electrophoresis of genomic DNA restricted with XbaI showed that two of these restriction fragment length polymorphism types were closely related, but the third was quite distinct. However, SLTEC strains of other serotypes, including O157:H-, were also isolated from some of the HUS patients.
 ...
PMID:Molecular microbiological investigation of an outbreak of hemolytic-uremic syndrome caused by dry fermented sausage contaminated with Shiga-like toxin-producing Escherichia coli. 878 57

Enterohemorrhagic Escherichia coli (EHEC) causes a variety of clinical conditions, the most important being hemorrhagic colitis and hemolytic uremic syndrome. A curative therapy of EHEC diseases is not yet feasible. This study investigates the antibody reactivity of Lactobin, a standardized immunoglobulin (Ig) preparation, obtained from the colostra of non-immunized cows. Three different batches of Lactobin exhibited equally high titers of specific antibodies against Shiga-like toxins (SLTs, verocytotoxins) and EHEC hemolysin (EHEC-Hly) produced by E. coli O157. In addition, Lactobin blocked the cytotoxic effect of SLT-I and SLT-II on Vero cell monolayers and inhibited the cytolytic effects of EHEC-Hly on human erythrocytes. Since Lactobin contains high levels of antibodies and neutralizing activity against important virulence factors of EHEC O157, this drug has potential use in the treatment of diarrhea and the prevention of EHEC-associated hemolytic uremic syndrome.
 ...
PMID:A standard immunoglobulin preparation produced from bovine colostra shows antibody reactivity and neutralization activity against Shiga-like toxins and EHEC-hemolysin of Escherichia coli O157:H7. 892 50

In 1997, Konowalchuk and coworkers reported a toxin produced by Escherichia coli that was cytotoxic to Vero cells. This toxin(Vero toxin, VT) was subsequently found to be an important virulence factor of E. coli associated with an outbreak of hemorrhagic colitis due to E. coli O157:H7 which occurred in the state of Oregon and Michigan in US. E. coli O157:H7 was then found to produce VT, which was cross-reactive with Shiga toxin produced by Shigella dysenteriae. VT(Shiga-like toxin Shiga toxin, Shiga toxin family) is the toxin which contributes to the symptoms of hemorrhagic colitis and hemolytic uremic syndrome. This article presents a historical perspective on EHEC and also reviews the structure and function of VT as well as epidemiological aspects of outbreak and sporadic cases of EHEC in American continent and in our county.
 ...
PMID:[Enterohemorrhagic Escherichia coli and its infection: from 1977 to 1995]. 908 72

Some of the virulent genes of enterohemorrhagic E. coli(EHEC) are described. stx, bfpA, eaeA and ehxA encode an enterocytotoxin homologous to Shiga toxin, bundle-forming pilus, intimin and an RTX toxin, respectively. In pathogenesis, although bfp and eae cause diarrhea, and ehx and stx seem to cause hemorrhagic colitis and hemolytic uremic syndrome, many problems remain for prevention and treatment of these symptoms. In evolution, it is intriguining that the virulent genes of EHEC might be mediated by phages, plasmids and so on, because stx is derived from a bacterio-phage, bfpA is located in a plasmid in enteropathogenic E. coli(EPEC) though it has not yet been cloned in EHEC, eaeA is one of the genes in LEE(locus of enterocyte effacement), a putative genetic cassette ubiquitous for EPEC and EHEC, and ehxA is in a plasmid.
 ...
PMID:[Genes involved in the virulence of enterohemorrhagic Escherichia coli]. 908 73


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>