Sequence analysis of the heat-labile enterotoxin subunit B gene originating in human enterotoxigenic Escherichia coli

1982 ◽  
Vol 152 (1) ◽  
pp. 506-509
Author(s):  
T Yamamoto ◽  
T Tamura ◽  
M Ryoji ◽  
A Kaji ◽  
T Yokota ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Signal Sequence ◽  
Enterotoxigenic Escherichia Coli ◽  
Mature Peptide ◽  
Terminal Sequence ◽  
E Coli ◽  
Amino Terminal ◽  
Heat Labile ◽  
Subunit B ◽  
Amino Terminal Sequence

In this study, we determined the amino-terminal coding sequence, covering the signal peptide and the amino-terminus of the mature peptide, of the heat-labile enterotoxin subunit B (LT-B) gene originating in human enterotoxigenic Escherichia coli. Neither the signal sequence nor the amino-terminal sequence of the mature LT-B was identical to those sequences from porcine enterotoxigenic E. coli, but there was an extensive homology.

scholarly journals Enterotoxigenic Escherichia coli infection and intestinal thiamin uptake: studies with intestinal epithelial Caco-2 monolayers

2013 ◽  
Vol 305 (11) ◽  
pp. C1185-C1191 ◽  
Author(s):  
Abhisek Ghosal ◽  
Nabendu S. Chatterjee ◽  
Tristan Chou ◽  
Hamid M. Said
Keyword(s):  
Escherichia Coli ◽  
Significant Inhibition ◽  
Water Soluble ◽  
Enterotoxigenic Escherichia Coli ◽  
Adenylate Cyclase System ◽  
Mrna Levels ◽  
Intestinal Epithelial ◽  
E Coli ◽  
Heat Labile ◽  
Etec Infection

Infections with enteric pathogens like enterotoxigenic Escherichia coli ( ETEC) is a major health issue worldwide and while diarrhea is the major problem, prolonged, severe, and dual infections with multiple pathogens may also compromise the nutritional status of the infected individuals. There is almost nothing currently known about the effect of ETEC infection on intestinal absorptions of water-soluble vitamins including thiamin. We examined the effect of ETEC infection on intestinal uptake of the thiamin using as a model the human-derived intestinal epithelial Caco-2 cells. The results showed that infecting confluent Caco-2 monolayers with live ETEC (but not with boiled/killed ETEC or nonpathogenic E. coli) or treatment with bacterial culture supernatant led to a significant inhibition in thiamin uptake. This inhibition appears to be caused by a heat-labile and -secreted ETEC component and is mediated via activation of the epithelial adenylate cyclase system. The inhibition in thiamin uptake by ETEC was associated with a significant reduction in expression of human thiamin transporter-1 and -2 (hTHTR1 and hTHTR2) at the protein and mRNA levels as well as in the activity of the SLC19A2 and SLC19A3 promoters. Dual infection of Caco-2 cells with ETEC and EPEC (enteropathogenic E. coli) led to compounded inhibition in intestinal thiamin uptake. These results show for the first time that infection of human intestinal epithelial cells with ETEC causes a significant inhibition in intestinal thiamin uptake. This inhibition is mediated by a secreted heat-labile toxin and is associated with a decrease in the expression of intestinal thiamin transporters.

Multiplex Real-Time PCR Detection of Heat-Labile and Heat-Stable Toxin Genes in Enterotoxigenic Escherichia coli †

2006 ◽  
Vol 69 (2) ◽  
pp. 412-416 ◽  
Author(s):  
MICHAEL A. GRANT ◽  
JINXIN HU ◽  
KAREN C. JINNEMAN
Keyword(s):  
Escherichia Coli ◽  
Real Time ◽  
Real Time Pcr ◽  
Membrane Filtration ◽  
Enterotoxigenic Escherichia Coli ◽  
Pcr Analysis ◽  
E Coli ◽  
Toxin Genes ◽  
Heat Stable ◽  
Heat Labile

A multiplex real-time PCR method was developed for detection of heat-labile and heat-stable toxin genes in enterotoxigenic Escherichia coli. Approximately 10 CFU per reaction mixture could be detected in rinsates from produce samples. Several foods representative of varieties previously shown to have caused enterotoxigenic E. coli outbreaks were spiked and enriched for 4 or 6 h. Both heat-labile and heat-stable toxin genes could be detected in the foods tested, with the exception of hot sauce, with threshold cycle values ranging from 25.2 to 41.1. A procedure using membrane filtration which would allow enumeration of the enterotoxigenic E. coli population in a food sample in less than 28 h by real-time PCR analysis of colonies picked from media highly selective for E. coli was also developed.

scholarly journals The amino-terminal sequence of the Xenopus laevis mitochondrial SSB is homologous to that of the Escherichia coli protein

FEBS Letters ◽  
1988 ◽  
Vol 235 (1-2) ◽  
pp. 267-270 ◽  
Author(s):  
C. Mahoungou ◽  
R. Ghrir ◽  
J.P. Lecaer ◽  
B. Mignotte ◽  
M. Barat-Gueride
Keyword(s):  
Escherichia Coli ◽  
Xenopus Laevis ◽  
Terminal Sequence ◽  
Amino Terminal ◽  
Amino Terminal Sequence

scholarly journals Use of colony pools for diagnosis of enterotoxigenic Escherichia coli diarrhea

1979 ◽  
Vol 9 (4) ◽  
pp. 493-497
Author(s):  
M H Merson ◽  
R B Sack ◽  
A K Kibriya ◽  
A Al-Mahmood ◽  
Q S Adamed ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Enterotoxigenic Escherichia Coli ◽  
Adult Males ◽  
E Coli ◽  
Heat Stable ◽  
Heat Labile ◽  
Stool Specimens ◽  
Stool Cultures ◽  
Made In

Diagnosis of enterotoxigenic Escherichia coli diarrhea was made in 109 adult males with an acute dehydrating cholera-like syndrome in Dacca, Bangladesh, by testing 10 colonies isolated from admission stool specimens for production of heat-labile and heat-stable toxins. Toxin testing of one colony yielded a diagnosis in 92% of the cases, testing of two colonies yielded a diagnosis in 95% of the cases, testing of a pool of 5 colonies yielded a diagnosis in 95% of the cases, and testing of a pool of 10 colonies yielded a diagnosis in 96% of the cases. From stool cultures obtained on subsequent days, toxin testing of individual colonies and pools revealed diminished efficacy of pooling with decreasing numbers of enterotoxin-positive isolates in the pool. To detect the presence of enterotoxigenic E. coli in stools, toxin testing of 5 individual isolates and a pool of 10 colonies was found to be almost as effective as the testing of 10 individual isolates.

Malate dehydrogenase: Isolation from E. coli and comparison with the eukaryotic mitochondrial and cytoplasmic forms

1981 ◽  
Vol 1 (6) ◽  
pp. 497-507 ◽  
Author(s):  
Ross T. Fernley ◽  
Steven R. Lentz ◽  
Ralph A. Aradshaw
Keyword(s):  
Malate Dehydrogenase ◽  
Deae Cellulose ◽  
Mitochondrial Enzymes ◽  
Terminal Sequence ◽  
E Coli ◽  
Amino Terminal ◽  
Common Precursor ◽  
Polypeptide Chains ◽  
Mitochondrial Malate Dehydrogenase ◽  
Amino Terminal Sequence

Escherichia coli malate dehydrogenase has been isolated in homogeneous form by a procedure employing chromatography on DEAE-cellulose, 5′-AMP-Sepharose, and Sephacryl-200. It is composed of two identical polypeptide chains each of Mr = 32 500. Like porcine mitochondrial malate dehydrogenase, it is devoid of tryptophan, but otherwise it is not particularly more similar in composition to one of the eukaryotic isozymes than to the other. However, amino-terminal sequence analysis of the first 36 residues shows remarkable similarity of the bacterial and mitochondrial enzymes (69% identical residues) in contrast to the cytoplasmic form (27%). The two porcine heart enzymes are identical in 24t% of the positions compared. These results clearly establish that all three forms of malate dehydrogenase have evolved from a common precursor and that the prokaryotic and mitochondrial forms have retained sequences that are much closer to the ancestral one than the cytoplasmic enzyme. These findings appear to further substantiate the endosymbiotic hypothesis for the origin of the mitochondrion.

scholarly journals Identification of a Gene within a Pathogenicity Island of Enterotoxigenic Escherichia coli H10407 Required for Maximal Secretion of the Heat-Labile Enterotoxin

2000 ◽  
Vol 68 (5) ◽  
pp. 2766-2774 ◽  
Author(s):  
James M. Fleckenstein ◽  
Luther E. Lindler ◽  
Eric A. Elsinghorst ◽  
James B. Dale
Keyword(s):  
Escherichia Coli ◽  
Pathogenicity Island ◽  
Open Reading Frames ◽  
Enterotoxigenic Escherichia Coli ◽  
Loop Model ◽  
Ileal Loop ◽  
E Coli ◽  
Link Type ◽  
Colonization Factor ◽  
Heat Labile

ABSTRACT Studies of the pathogenesis of enterotoxigenic Escherichia coli (ETEC) have largely centered on extrachromosomal determinants of virulence, in particular the plasmid-encoded heat-labile (LT) and heat-stable enterotoxins and the colonization factor antigens. ETEC causes illnesses that range from mild diarrhea to severe cholera-like disease. These differences in disease severity are not readily accounted for by our current understanding of ETEC pathogenesis. Here we demonstrate that Tia, a putative adhesin of ETECH10407 , is encoded on a large chromosomal element of approximately 46 kb that shares multiple features with previously described E. coli pathogenicity islands. Further analysis of the region downstream from tia revealed the presence of several candidate open reading frames (ORFs) in the same transcriptional orientation as tia. The putative proteins encoded by these ORFs bear multiple motifs associated with bacterial secretion apparatuses. An in-frame deletion in one candidate gene identified here as leoA (labile enterotoxin output) resulted in marked diminution of secretion of the LT enterotoxin and lack of fluid accumulation in a rabbit ileal loop model of infection. Although previous studies have suggested that E. coli lacks the capacity to secrete LT, our studies show that maximal release of LT from the periplasm of H10407 is dependent on one or more elements encoded on a pathogenicity island.

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