Escherichia coli strain 86, isolated from a piglet with diarrhea, carries plasmid-linked genes for resistance to tetracycline, streptomycin, and sulfonamides and for production of heat-labile and heat-stable enterotoxin. Results of (i) genetic experiments involving conjugal transfer and phage P1-mediated transduction and (ii) physical experiments involving electron microscopic examination of pl...

Previous studies of the S1 subunit of pertussis toxin, an NAD(+)-dependent ADP-ribosyltransferase, suggested that a small amino-terminal region of amino acid sequence similarity to the active fragments of both cholera toxin and Escherichia coli heat-labile enterotoxin represents a region containing critical active-site residues that might be involved in the binding of the substrate NAD+. Other ...

Enterotoxigenic Escherichia coli (ETEC) diarrheal disease is a worldwide problem that may be addressed by transcutaneous delivery of a vaccine. In several human settings, protective immunity has been associated with immune responses to E. coli colonization factors and to the heat-labile toxin that induces the diarrhea. In this set of animal studies, transcutaneous immunization (TCI) using recom...

We demonstrated that both the A and B subunits of heat-labile enterotoxin from Escherichia coli are located in the periplasm. The toxin was shown to form aggregates in Tris-EDTA buffers which are routinely used for isolating membranes. The aggregates pellet upon centrifugation, and this may explain why several previous investigators have concluded that enterotoxin is associated with membranes.

We report a rapid competitive enzyme-linked immunosorbent assay to screen Salmonella typhimurium strains for cholera-related enterotoxin antigens. Polymyxin B extracts of bacterial cells from syncase-glucose broth cultures of 7 of 15 strains gave positive results. The specificity of the test was confirmed with known heat-labile-enterotoxin-positive and -negative Escherichia coli strains which g...

Objective(s): Enterotoxigenic Escherichia coli (ETEC) is known as the most common bacterial causes of diarrheal diseases related to morbidity and mortality. Heat-labile enterotoxin (LT) is a part of major virulence factors in ETEC pathogenesis. Antigen entrapment into nanoparticles (NPs) can protect them and enhance their immunogenicity.Materials and Methods: In the present study, recombinant L...

Rats immunized with Escherichia coli heat-labile (LT) enterotoxin, either in the form of the holotoxin derived from a transformed K-12 strain or the polymyxin-release form obtained from human strains which produce LT toxin alone (LT+/ST- [ST is heat-stable toxin)] or together with ST toxin (LT+/ST+), were challenged with viable organisms of 10 different serotypes, 5 LT+/ST- and 5 LT+/ST+. The s...