When Shiga toxin-producing Escherichia coli (STEC) strains emerged as agents of human disease, two types toxin were identified: type 1 (Stx1) (almost identical to produced by Shigella dysenteriae 1) and the immunologically distinct 2 (Stx2). Subsequently, numerous STEC have been characterized that express toxins with variations in amino acid sequence, some which confer unique biological properties. These variants grouped within Stx1 or Stx2 often assigned names indicate they not sequence...

Escherichia coli K-12 acquired the ability to produce a high titer of Shiga-like toxin after lysogenization by either two different bacteriophages isolated from highly toxinogenic O157:H7 strain that causes hemorrhagic colitis. One these phages and another toxin-converting phage an O26 isolate associated with infantile diarrhea were closely related in terms morphology, virion polypeptides, DNA restriction fragments, lysogenic immunity, heat stability, although difference host range was...

Escherichia coli O157:H7 strain 933 contains two distinct toxin-converting phages (933J and 933W). The biologic activities antigenic relationship between the toxins produced by 933J 933W lysogens of E. K-12, as well homology genes that encode toxins, were examined in this study. like Shiga toxin Shigella dysenteriae type 1, cytotoxic for same cell lines, caused paralysis death mice, fluid accumulation rabbit ileal segments. activity HeLa cells was neutralized anti-Shiga toxin, whereas not...

Journal Article The Diarrheal Response of Humans to Some Classic Serotypes Enteropathogenic Escherichia coli is Dependent on a Plasmid Encoding an Enteroadhesiveness Factor Get access Myron M. Levine, Levine Search for other works by this author on: Oxford Academic PubMed Google Scholar James P. Nataro, Nataro Helge Karch, Karch Mary Baldini, Baldini B. Kaper, Kaper Robert E. Black, Black Lou Clements, Clements Alison D. O'Brien Infectious Diseases, Volume 152, Issue 3, September 1985, Pages...

Strains of Escherichia coli previously implicated or proven to be causes diarrhea were examined for production a toxin similar that Shigella dysenteriae type 1 (Shiga). Organisms grown in an iron-depleted broth lysed by pressure disruption followed ultracentrifugation. Saline-dialyzed extracts tested cytotoxic effects on HeLa cells neutralizable with antiserum Shiga toxin. Among the 13 E. strains so analyzed, 11 made Shiga-like cytotoxin levels ranging from trace (two avirulent isolates)...

This study investigated whether soluble paracrine factors mediated Salmonella-induced IL-8 expression in polarized model intestinal epithelia. We found that the basolateral media of epithelia had been apically infected with Salmonella typhimurium for a short period (10 minutes) could activate secretion virgin epithelia, demonstrating proinflammatory factor (PIF) was indeed present. Initial characterization PIF heat-stable protein molecular mass about 50 kDa acts on basolateral, but not...

In earlier studies using a streptomycin-treated mouse model of infection caused by enterohemorrhagic Escherichia coli (EHEC), animals fed Shiga-like toxin type II (SLT-II)-producing strains developed acute renal cortical necrosis and died, while mice I (SLT-I)-producing clones did not die (E. A. Wadolkowski, L. M. Sung, J. Burris, E. Samuel, D. O'Brien, Infect. Immun. 58:3959-3965, 1990). To examine the bases for differences we noted between two toxins in murine model, injected with purified...

The nucleotide sequence of the Shiga-like toxin type II (SLT-II) structural genes cloned from bacteriophage 933W enterohemorrhagic Escherichia coli O157:H7 strain 933 was determined. This compared with published for antigenically distinct I (SLT-I) encoded by 933J. SLT-I and SLT-II shared 58% overall 56% amino acid homologies. A B subunits were nearly identical in size had similar secondary structures hydropathy plots. regulation proposed operon is to that previously SLT-I.

The eaeA gene of enteropathogenic Escherichia coli (EPEC) is necessary for intimate attachment to epithelial cells in vitro.Enterohemorrhagic E. (EHEC) strains also possess an eac and are capable microvillus effacement vitro animal models.To assess the role EHEC eae attachment, we constructed deletion/insertion mutation wild-type 0157:H7 strain 86-24 by using linear electroporation a recombinant allele.The mutant obtained was deficient inducing f-actin accumulation HEp-2 incapable attaching...

A Shiga-like toxin type II variant (SLT-IIv) is produced by strains of Escherichia coli responsible for edema disease swine and antigenically related to (SLT-II) enterohemorrhagic E. coli. However, SLT-IIv only active against Vero cells, whereas SLT-II both HeLa cells. The structural genes were cloned from S1191, the nucleotide sequence was determined compared with those other members Shiga family. subunit highly homologous (94%), B less (79%). more distantly (55 60% overall homology)...

Several serotypes of Escherichia coli produce protein toxins closely related to Shiga toxin (Stx) from Shigella dysenteriae serotype 1. These Stx-producing E. cause outbreaks hemorrhagic colitis and hemolytic uremic syndrome in humans, with the latter being more likely if Stx2 than they only Stx1. To investigate differences among Stxs, which are all AB5 toxins, crystal structure O157:H7 was determined at 1.8-Å resolution compared known Stx. Our major finding that, contrast Stx, active site...

The structural genes for Shiga toxin, designated stx A and B, were cloned from Shigella dysenteriae type 1 3818T, a nucleotide sequence analysis was performed. Both B present on single transcriptional unit, with preceding B. molecular weight calculated the processed subunit 32,225, while of 7,691. Comparison sequences toxin Shiga-like I (SLT-I) Escherichia coli revealed that SLT-I greater than 99% homologous; three changes detected in separate codons subunits. Only one these codon...

The mouse Chromosome 1 locus Ity regulates the extent to which Salmonella typhimurium replicates within reticuloendothelial cell system (RES) during first days of infection. If animals are homozygous for Itys susceptibility allele, Gram-negative bacterium undergoes rapid net multiplication, and mice die a typhoid fever-like disease by day 10 Animals that or heterozygous resistance Ityr, control bacterial replication survive phase salmonellosis. Indirect studies have implicated resident...

A toxin from an enteropathogenic strain of Escherichia coli (E. H30) was purified to apparent homogeneity cell lysates. The steps used isolate the E. H30 included French pressure-cell disruption bacteria grown in iron-depleted media. Affi-Gel Blue chromatography, chromatofocusing, and anti-Shiga affinity chromatography. mobilities subunits radioiodinated Shiga observed after two toxins were subjected sodium dodecyl sulfate-polyacrylamide gel electrophoresis identical. In absence...

Thirty-two clinical isolates of Shiga-like toxin (SLT)-producing Escherichia coli associated with single cases or outbreaks bloody diarrhea, hemorrhagic colitis, the hemolytic uremic syndrome, edema disease swine were examined for multiple copies genes belonging to slt-I slt-II families. Five 19 strains that known produce SLT-II hybridize slt-II-specific probes by colony blot found Southern hybridization contain two related slt-II. The toxins closely cloned from one isolates, O157:H- strain...

Ricin, Shiga toxin, and Shiga-like toxin II (SLT-II, Vero 2) exhibit an RNA N-glycosidase activity which specifically removes a single base near the 3′ end of 28 S rRNA in isolated rat liver ribosomes deproteinized (Endo Y., Mitsui, K., Moti-zuki, M., & Tsurugi, K. (1987) J. Biol. Chem. 262, 5908–5912; Endo Y. 8128–8130, Endo, Yut-sudo, T., Takeda, Ogasawara, Igarashi, (1988) Eur. Biochem. 171, 45–50). These workers identified removed, A-4324, by examining degradation product was generated...

Enterohemorrhagic Escherichia coli O157:H7 isolates produce Shiga-like toxins and carry a 60-megadalton plasmid which encodes an adhesin for Henle 407 intestinal cells. A streptomycin-treated mouse model was used to compare the colonizing capacity of E. strain 933 with that its plasmid-cured derivative, 933cu. When fed individually mice, both 933cu maintained stable number organisms per gram feces, greatest numbers or were isolated from cecal proximal colonic epithelial simultaneously unable...

ABSTRACT Enterohemorrhagic Escherichia coli (EHEC) strains require intimin to induce attaching and effacing (A/E) lesions in newborn piglets. Infection of calves with intimin-positive or intimin-negative EHEC O157:H7 demonstrated that is needed for colonization, A/E lesions, disease cattle. These results suggest experiments determine if intimin-based vaccines reduce levels cattle are warranted.