Cholera toxin (CT), the enterotoxin secreted by Vibrio cholerae classical as well as El Tor biotypes, is the major causative agent of the acute diarrheal disease of humans. CT and the Escherichia coli heat labile enterotoxin (LT),are structurally and immunologically highly homologous,seeing that they belong to the same enterotoxin family (de Haan and Hirst, 2004; Spangler, 1992; Vanden Broeck e...

The morphological response of Vero cells to Escherichia coli heat-labile enterotoxin was similar to that of cholera toxin and was accompanied by increases in the intracellular level of cyclic AMP. The effects of both enterotoxins were enhanced by the presence of phosphodiesterase inhibitor and inhibited by heat or specific antisera. Accumulation of cyclic AMP preceded the morphological response.

A latex particle agglutination test is described which is suitable for the recognition of heat-labile enterotoxin-producing colonies of Escherichia coli immediately after primary culture on a variety of commonly used enteric diagnostic media. The test is simple and economical to perform, and the results are available in minutes.

The astA gene responsible for production of enteroaggregative Escherichia coli heatstable enterotoxin 1 (EAST1) was identified in E. coli strains isolated from pigs with postweaning diarrhea. Two hundred and twenty-six isolates were tested using PCR for the astA marker as well as for heat-labile I (LTI), heat-stable I (STI), and heat-stable II (STII) enterotoxin genes characteristic for enterot...

Two of 49 cytolethal distending toxin-producing strains of Escherichia coli isolated from human stools contained the gene coding for heat-stable enterotoxin b (STb), as detected by a colony hybridization assay. The STb gene was found to be on a 70-kb plasmid also coding for heat-labile enterotoxin (pLT-I). Restriction endonuclease analysis showed the STb gene from human isolates to be similar t...

Enterotoxigenic Escherichia coli (ETEC) infections are a significant cause of diarrheal disease and infant mortality in developing countries. Studies of ETEC pathogenesis relevant to vaccine development have been greatly hampered by the lack of a suitable small-animal model of infection with human ETEC strains. Here, we demonstrate that adult immunocompetent outbred mice can be effectively colo...

Genetically modified derivatives of cholera toxin (CT), harboring a single amino acid substitution in and around the NAD binding cleft of the A subunit, were isolated following site-directed mutagenesis of the ctxA gene. Two mutants of CT, designated CTS106 (with a proline-to-serine change at position 106) and CTK63 (with a serine-to-lysine change at position 63), were found to have substantial...

Cholera vibrios produce a single polymeric protein that (i) causes hemagglutination; (ii) appears to participate in their attachment to gut epithelium; (iii) may mediate their detachment from gut epithelium; and (iv) is a protease that hydrolyzes fibronectin and mucin, cleaves lactoferrin, and nicks the A subunit of the choleragen-related heat-labile enterotoxin of Escherichia coli.

A latex particle agglutination test previously shown to be suitable for the rapid identification of Escherichia coli strains of human origin producing heat-labile enterotoxin (R. A. Finkelstein and Z. Yang, J. Clin. Microbiol. 18:23-28) is equally applicable to strains of porcine origin.

Hybridoma cell lines which produced monoclonal antibodies against cholera toxin were isolated. These cell lines were detected with an enzyme-linked immunosorbent assay screening procedure with purified cholera toxin or subunit A of cholera toxin. Seven cell lines were characterized with respect to their reactivity with cholera toxin subunits by Western blot analysis. Five clones produced antibo...