Induction of E. coli recA protein via recBC and alternate pathways: Quantitation by enzyme-linked immunosorbent assay (ELISA)

1982 ◽  
Vol 185 (2) ◽  
pp. 275-282 ◽  
Author(s):  
Alexander E. Karu ◽  
Elaine D. Belk
Keyword(s):  
Immunosorbent Assay ◽  
Reca Protein ◽  
Enzyme Linked Immunosorbent Assay ◽  
E Coli

Use of a Shiga Toxin (Stx)-Enzyme-Linked Immunosorbent Assay and Immunoblot for Detection and Isolation of Stx-Producing Escherichia coli from Naturally Contaminated Beef

2000 ◽  
Vol 63 (9) ◽  
pp. 1167-1172 ◽  
Author(s):  
HEBA NASHED ATALLA ◽  
ROGER JOHNSON ◽  
SCOTT MCEWEN ◽  
R. W. USBORNE ◽  
C. L. GYLES
Keyword(s):  
Escherichia Coli ◽  
Vero Cell ◽  
Immunosorbent Assay ◽  
Shiga Toxin ◽  
Total Coliform ◽  
Complete Agreement ◽  
Enzyme Linked Immunosorbent Assay ◽  
Spearman Correlation ◽  
Southern Ontario ◽  
E Coli

The purpose of this study was to evaluate an enzyme-linked immunosorbent assay (ELISA) and an immunoblot procedure for detection and isolation of Shiga toxin-producing Escherichia coli (STEC) from beef, and to correlate the presence of STEC in beef with E. coli and total coliform counts. A total of 120 samples of boneless beef supplied to a meat processor in southern Ontario were tested for the presence of STEC, E. coli, and total coliforms. Following enrichment in modified tryptic soy broth, samples were screened for Shiga toxin (Stx) by a Stx-ELISA and a Vero cell assay (VCA). Samples that were positive in the Stx-ELISA were subjected to the Stx-immunoblot for STEC isolation. Overall, 33.3% of samples were positive in the VCA, and 34.2% were positive in the Stx-ELISA. There was almost complete agreement between the Stx-ELISA and the VCA results (kappa = 0.98). The sensitivity and specificity of the Stx-ELISA with respect to the VCA were 100% and 98.75%, respectively. STEC were isolated by the Stx-immunoblot from 87.8% of the samples that were positive in the Stx-ELISA. The STEC isolates belonged to 19 serotypes, with serotype O113:H21 accounting for 10 of 41 isolates. No STEC of serotype O157:H7 were isolated. There was a significant correlation between E. coli counts and total coliform counts (Spearman correlation coefficient = 0.68, P < 0.01). The E. coli count was positively correlated with detection of STEC by both the Stx-ELISA and the VCA (P < 0.01).

Evaluation of Three Commercially Available Enzyme-Linked Immunosorbent Assay Kits for Detection of Shiga Toxin

2009 ◽  
Vol 72 (4) ◽  
pp. 741-747 ◽  
Author(s):  
JOHN WILLFORD ◽  
KENNETH MILLS ◽  
LAWRENCE D. GOODRIDGE
Keyword(s):  
Escherichia Coli ◽  
Immunosorbent Assay ◽  
Shiga Toxin ◽  
Screening Method ◽  
Enzyme Linked Immunosorbent Assay ◽  
Microplate Assay ◽  
E Coli ◽  
Elisa Kit ◽  
Pure Cultures ◽  
Order Of Magnitude

Three commercially available Shiga toxin (Stx) enzyme-linked immunosorbent assay (ELISA) kits were evaluated for their ability to detect Stx in pure cultures of Stx-producing Escherichia coli (specificity). The detection limits (sensitivity) of each ELISA kit were also evaluated. Seventy-eight Stx-producing E. coli (STEC) isolates that produced Stx1, Stx2, or Stx1 and Stx2 variants were examined in this study. The specificities of the tests were comparable, and the sensitivities of two of the tests (Premier EHEC and rBiopharm Ridascreen Verotoxin Enzyme Immunoassay) were within the same order of magnitude. The ProSpecT Shiga Toxin E. coli Microplate Assay was approximately 10-fold less sensitive. The inability of all three tests to detect the Stx2d and Stx2e variants indicated that some STEC strains may not be detected by Stx ELISA. The ability of the Premier EHEC ELISA to detect toxin in artificially inoculated bovine fecal samples (following enrichment) indicated that this kit may be used to screen cattle for the presence of Stx as an indicator of the presence of STEC. In particular, such a screening method could be useful during the summer, when the number of STEC-positive animals and the number of STEC that they shed increase.

scholarly journals Enzyme-linked immunosorbent assay for detection of Escherichia coli heat-labile enterotoxin

1977 ◽  
Vol 6 (5) ◽  
pp. 439-444 ◽  
Author(s):  
R H Yolken ◽  
H B Greenberg ◽  
M H Merson ◽  
R B Sack ◽  
A Z Kapikian
Keyword(s):  
Escherichia Coli ◽  
Immunosorbent Assay ◽  
Radioactive Isotope ◽  
Enzyme Linked Immunosorbent Assay ◽  
Adrenal Cell ◽  
Elisa System ◽  
Culture Techniques ◽  
E Coli ◽  
Heat Labile ◽  
Tissue Culture Techniques

The development of an enzyme-linked immunosorbent assay (ELISA) for the detection of heat-labile Escherichia coli enterotoxin is described. The assay, which is based on the immunological similarity between Vibrio cholerae toxin and heat-labile E. coli enterotoxin, is similar in design to a radioimmunoassay but utilizes enzyme-labeled rather than radioactive isotope-labeled reagents. The ELISA system is as sensitive as both radioimmunoassay and the y-1 adrenal cell assay for the detection of heat-labile E. coli enterotoxin but requires neither radioactive reagents nor tissue culture techniques. The ELISA is easy to perform and is adaptable for use in small laboratories.

scholarly journals Evaluation of home-mode ELISA system for thedetection of antibodies against Escherichia coli O157:H7 using purified lipopolysaccharide

2008 ◽  
Vol 5 (4) ◽  
pp. 563-568
Author(s):  
Baghdad Science Journal
Keyword(s):  
Escherichia Coli ◽  
Immunosorbent Assay ◽  
Gel Filtration ◽  
Laboratory Animals ◽  
Partial Purification ◽  
Nucleic Acid Content ◽  
Enzyme Linked Immunosorbent Assay ◽  
Biochemical Basis ◽  
Elisa System ◽  
E Coli

An enzyme linked immunosorbent assay (ELISA) for the detection and quantitation of human immunoglobulin G (IgG) antibodies against vero- cytotoxine (VT) producing Escherichia coli serogroup O157:H7 was produced. E. coli O157: H7 lipopolysaccharide was extracted from locally isolated strains by using hot phenol- water method, followed by partial purification using gel filtration chromatography by sepharose- 4B. The purity of the lipopolysaccharide was checked by measuring the protein and nucleic acid content and then used as antigen. Four isolates of vero- cytotoxin producing E. coli serogroup O157:H7 was obtained by culturing 350 stool samples from children suffering from bloody diarrhea. These isolates were identified on bacteriological, serological and biochemical basis. Toxin production was confirmed on laboratory animals as well as by cytopathic effect on tissue culture. The possibility of using E. coli O157:H7 lipopolysaccharide in an enzyme- linked immunosorbent assay for the routine diagnostic testing of serum from patients for evidence of O157:H7 infection is discussed.

Detection of Escherichia coli O157 in Foods by a Novel Polymyxin-Based Enzyme-Linked Immunosorbent Assay

2005 ◽  
Vol 68 (2) ◽  
pp. 233-238 ◽  
Author(s):  
BURTON W. BLAIS ◽  
JOHANNA LEGGATE ◽  
JESSICA BOSLEY ◽  
AMALIA MARTINEZ-PEREZ
Keyword(s):  
Escherichia Coli ◽  
Immunosorbent Assay ◽  
Microtiter Plate ◽  
Complete Agreement ◽  
Enzyme Linked Immunosorbent Assay ◽  
Escherichia Coli O157 ◽  
Elisa System ◽  
Culture Techniques ◽  
E Coli ◽  
Affinity Adsorbent

An enzyme-linked immunosorbent assay (ELISA) system was developed using polymyxin immobilized in the wells of a microtiter plate as a high-affinity adsorbent for Escherichia coli O157 lipopolysaccharide (LPS) antigens. Extracts from cell suspensions were reacted with polymyxin-coated microwells followed by immunoenzymatic detection of captured LPS antigens using a commercially available anti–E. coli O157 antibody–peroxidase conjugate and a 3,3′,5,5′-tetramethylbenzidine substrate. The polymyxin ELISA was highly sensitive and specific for E. coli strains bearing the O157 antigen. When this ELISA was combined with enrichment, results were in complete agreement with those of standard culture techniques for the detection of this pathogen in a variety of artificially inoculated and naturally contaminated foods. The polymyxin ELISA is a simple and inexpensive assay for E. coli O157 with a 96-well microtiter plate format, making this system ideally suited for processing large numbers of samples.

scholarly journals Development of a Blocking Enzyme-Linked Immunosorbent Assay for Detection of Serum Antibodies to O157 Antigen ofEscherichia coli

1998 ◽  
Vol 5 (2) ◽  
pp. 242-246 ◽  
Author(s):  
William Laegreid ◽  
Mark Hoffman ◽  
James Keen ◽  
Robert Elder ◽  
Jimmy Kwang
Keyword(s):  
Escherichia Coli ◽  
Immunosorbent Assay ◽  
Brucella Abortus ◽  
Indirect Elisa ◽  
Bacterial Species ◽  
Enzyme Linked Immunosorbent Assay ◽  
Specific Method ◽  
Structural Elements ◽  
Serum Antibodies ◽  
E Coli

ABSTRACT The O157 antigen of Escherichia coli shares structural elements with lipopolysaccharide (LPS) antigens of other bacterial species, notably Brucella abortus and Yersinia enterocolitica O9, a fact that confounds the interpretation of assays for anti-O157 antibodies. To address this problem, a blocking enzyme-linked immunosorbent assay (bELISA) was designed with E. coli O157:H7 LPS as the antigen and a monoclonal antibody specific for E. coli O157, designated 13B3, as the competing antibody. The bELISA had equivalent sensitivity to, and significantly higher specificity than, the indirect ELISA (iELISA), detecting anti-O157 antibodies in sera from cattle experimentally inoculated with O157:H7. Only 13% of sera from naive heifers vaccinated for or experimentally infected with B. abortus had increased anti-O157 bELISA titers, while 61% of anti-O157 iELISA titers were increased. The bELISA is a sensitive and specific method for the detection of serum antibodies resulting from exposure to E. coli O157.

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