Infection of children with Shiga toxin (Stx)-producing Escherichia coli (STEC) is the leading cause of hemolytic-uremic syndrome (HUS). Stx2, one of two toxins liberated by the bacteria, is directly linked with HUS. We have previously shown that Stx2-specific human monoclonal antibodies (HuMAbs) protect mice and piglets from fatal systemic complications of Stx2. The present study investigates t...

Human CD4+ T-cell clones specific for pertussis toxin and other Bordetella pertussis antigens have been tested for their cytotoxic activity, lymphokine production, and capacity to induce immunoglobulin synthesis. Clones specific for the S1 subunit of pertussis toxin were cytotoxic for autologous Epstein-Barr virus-transformed B cells, which had been pulsed with the native antigen, the recombina...

BACKGROUND The BD MAX™ Enteric Bacterial Panel (BDM-EBP) is designed and FDA-cleared to detect Salmonella, Shigella, Campylobacter, and Shiga toxin genes stx1/2 from stool samples. However, rectal swabs, which are not FDA-cleared for clinical testing with the BDM-EBP, are common specimens received from pediatric patients for enteric pathogen testing. The purpose of this study was to evaluate th...

We have cloned a 4.5 kb EcoRI/BamHI DNA fragment from Bordetella pertussis which contains at least two genes responsible for expression of pertussis toxin. The S4 subunit of the toxin was isolated by high pressure liquid chromatography and the NH2-terminal amino acid sequence determined. Using a mixed synthetic oligonucleotide probe designed by reverse translation of a portion of the protein se...

Diphtheria toxin ( DTx ) is an extremely potent inhibitor of protein synthesis. It is secreted as a linear polypeptide, which is cleaved to produce disulfide-linked A and B fragments. Fragment A, the inhibitor of protein synthesis, requires fragment B, the recognition subunit, for entry into intact cells. Fragment B has been proposed to form a transmembrane channel through which A gains access ...

Upon release from the stable complex formed with its antitoxin VapB, the toxin VapC (MvpT) of the Gram-negative pathogen Shigella flexneri is capable of globally down-regulating translation by specifically cleaving initiator tRNA(fMet) in the anticodon region. Recombinant Shigella flexneri VapC(D7A) harbouring an active-site mutation was overexpressed in Escherichia coli, purified to homogeneit...

Shiga-like toxin-1 (SLT-1) is a bacterial toxin that kills cells by inhibiting protein synthesis. SLT-1 is composed of one cytotoxic A-subunit and five B-subunits that bind to CD77, a cell-surface glycolipid. In the human hematopoietic system, CD77 expression is restricted to a subset of activated B cells and derived cancers. Here we report that SLT-1 treatment of murine bone marrow ex vivo eff...

Although most enteropathogenic Escherichia coli strains do not produce recognized enterotoxins, we wished to examine whether they produce any factors like heat-stable enterotoxin b or cholera toxin active subunits that might be missed by conventional assay methods. E. coli strains E851 (O142) and E2348 (O127) that had caused diarrhea in volunteers were negative for heat-labile enterotoxin and h...

Many bacterial pathogens encode the cytolethal distending toxin (CDT), which causes host cells to arrest during their cell cycle by inflicting DNA damage. CDT is composed of three proteins, CdtA, CdtB, and CdtC. CdtB is the enzymatically active or A subunit, which possesses DNase I-like activity, whereas CdtA and CdtC function as heteromeric B subunits that mediate the delivery of CdtB into hos...

The interaction of pertussis toxin (PT) with cells and model membranes was investigated by examining PT-induced intoxication of Chinese hamster ovary cells and by studying the binding of PT and its subunits to phospholipid vesicles. Since certain bacterial toxins require an acidic environment for efficient interaction with membranes and subsequent entry into the cell, the requirement for an aci...