Biomaterial Database

A method for detecting Shiga toxin and Shiga-like toxin-I in pure and mixed culture. 1990

S Ashkenazi, and T G Cleary

Department of Pediatrics, University of Texas Medical School, Houston 77030.

Shiga toxin and Shiga-like toxins (SLTs, syn. Verotoxins) are currently detected by tissue culture assays that are expensive, time-consuming and require specialised facilities and experienced personnel. We have developed a rapid method to detect Shiga toxin and SLT-I (Verotoxin 1) based on their binding to globotriosyl ceramide (Gb3). Bound toxin was then detected by an enzyme-linked immunosorbent assay (ELISA) with monoclonal antibodies. The direct detection of cytotoxins from pure culture plates and from a mixed bacterial culture was studied. Using polymyxin extraction (0.1 g/L, 30 min, 37 degrees C) and Gb3-based ELISA we detected toxin from reference strains Shigella dysenteriae 1 strain 60R (Shiga toxin) and Escherichia coli O26:H11 strain H30 (SLT-I), and from clinical isolates of E. coli O157:H7 and O26:H11 (both SLT-I) from 11 patients with diarrhoea, haemorrhagic colitis or haemolytic uraemic syndrome. Toxin production by these strains was confirmed by a radiolabelled HeLa cell assay and the structural genes were detected by DNA hybridisation. The Gb3-based ELISA could detect SLT-I in extracts of a mixed culture even when the toxin-positive strains represented only 1% of the mixture. No cross-reactivity was found with bacteria that produce other cytotoxins, such as other E. coli and Shigella, Salmonella, Aeromonas and Campylobacter spp.

UI	MeSH Term	Description	Entries
D009693	Nucleic Acid Hybridization	Widely used technique which exploits the ability of complementary sequences in single-stranded DNAs or RNAs to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (Kendrew, Encyclopedia of Molecular Biology, 1994, p503)	Genomic Hybridization,Acid Hybridization, Nucleic,Acid Hybridizations, Nucleic,Genomic Hybridizations,Hybridization, Genomic,Hybridization, Nucleic Acid,Hybridizations, Genomic,Hybridizations, Nucleic Acid,Nucleic Acid Hybridizations
D011112	Polymyxin B	A mixture of polymyxins B1 and B2, obtained from BACILLUS POLYMYXA strains. They are basic polypeptides of about eight amino acids and have cationic detergent action on cell membranes. Polymyxin B is used for treatment of infections with gram-negative bacteria, but may be neurotoxic and nephrotoxic.	Aerosporin,Polymyxin B Sulfate
D003603	Cytotoxins	Substances that are toxic to cells; they may be involved in immunity or may be contained in venoms. These are distinguished from CYTOSTATIC AGENTS in degree of effect. Some of them are used as CYTOTOXIC ANTIBIOTICS. The mechanism of action of many of these are as ALKYLATING AGENTS or MITOSIS MODULATORS.	Cytolysins,Cytotoxic Agent,Cytotoxic Agents,Cytotoxin,Agent, Cytotoxic
D004768	Enterotoxins	Substances that are toxic to the intestinal tract causing vomiting, diarrhea, etc.; most common enterotoxins are produced by bacteria.	Staphylococcal Enterotoxin,Enterotoxin,Staphylococcal Enterotoxins,Enterotoxin, Staphylococcal,Enterotoxins, Staphylococcal
D004797	Enzyme-Linked Immunosorbent Assay	An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.	ELISA,Assay, Enzyme-Linked Immunosorbent,Assays, Enzyme-Linked Immunosorbent,Enzyme Linked Immunosorbent Assay,Enzyme-Linked Immunosorbent Assays,Immunosorbent Assay, Enzyme-Linked,Immunosorbent Assays, Enzyme-Linked
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D001427	Bacterial Toxins	Toxic substances formed in or elaborated by bacteria; they are usually proteins with high molecular weight and antigenicity; some are used as antibiotics and some to skin test for the presence of or susceptibility to certain diseases.	Bacterial Toxin,Toxins, Bacterial,Toxin, Bacterial
D022603	Shiga Toxins	A class of toxins that inhibit protein synthesis by blocking the interaction of ribosomal RNA; (RNA, RIBOSOMAL) with PEPTIDE ELONGATION FACTORS. They include SHIGA TOXIN which is produced by SHIGELLA DYSENTERIAE and a variety of shiga-like toxins that are produced by pathologic strains of ESCHERICHIA COLI such as ESCHERICHIA COLI O157.	Vero Toxin,Vero Toxins,Shiga-Like Toxins,Vero Cell Cytotoxin,Vero Cell Cytotoxins,Vero Cytotoxin,Vero Cytoxins,Verotoxin,Verotoxins,Cell Cytotoxins, Vero,Cytotoxin, Vero,Cytotoxin, Vero Cell,Cytotoxins, Vero Cell,Cytoxins, Vero,Shiga Like Toxins,Toxin, Vero,Toxins, Shiga,Toxins, Shiga-Like,Toxins, Vero
D022622	Shiga Toxin 1	A toxin produced by certain pathogenic strains of ESCHERICHIA COLI such as ESCHERICHIA COLI O157. It is closely related to SHIGA TOXIN produced by SHIGELLA DYSENTERIAE.	SLT-I,SLTI,Shiga-Like Toxin I,Stx1 Protein,VT1 Cytotoxin,Vero Cytotoxin VT1,Verocytotoxin 1,Verotoxin I,Protein, Stx1,SLT I,Shiga Like Toxin I