Enzymes known to specifically cleave the band 3 component of the rabbit erythrocyte membrane were found to reduce both the hemolytic sensitivity to and the binding of the alpha toxin of Staphylococcus aureus. Lectins which bind to band 3 also inhibited the toxin. Lectins which do not bind to band 3 have no effect. Purified band 3, isolated by affinity chromatography on a concanavalin A column, ...

in this research a molecular method based on polymerase chain reaction for typing of clostridium perfringens was developed and toxin genotypes of 64 isolates from sheep and goats in iran were determined. the pcr assays were developed for detection of alpha (cpa), beta (cpb) and epsilon (etx) toxin genes, allowing classification of the isolates into genotypes a b, c and d. the field isolates ...

Staphylococcus aureus toxic shock syndrome toxin 1 (TSST-1) is involved in the pathogenesis of toxic shock syndrome and perhaps other staphylococcal diseases. Recently, the C-terminal part of the TSST-1 toxin has been shown to be responsible for mitogenic activity in animal models. We studied the role of the C-terminal structural unit of TSST-1 with regard to proliferation, cytokine release (tu...

BACKGROUND Cardiac performance is severely depressed in septic shock. Endotoxin has been implicated as the causative agent in Gram-negative sepsis, but similar abnormalities are encountered in Gram-positive sepsis. We investigated the influence of the major exotoxin of Staphylococcus aureus, staphylococcal alpha-toxin, in isolated perfused rat hearts. METHODS AND RESULTS Alpha-toxin 0.25 to 1...

Bordetella pertussis causes whooping cough, an endemic respiratory disease that is increasing in prevalence despite vaccination efforts. Although host immunity is modulated by virulence factors of this pathogen, it is unclear what host factors are required to overcome their effects. Here, we investigate an apparent relationship between the effects of pertussis toxin and tumor necrosis factor (T...

The subcellular distribution of the alpha 2-adrenergic receptor, pertussis-toxin substrates (Gi, the inhibitory G-protein) and adenylate cyclase was determined in human platelets. The alpha 2-adrenergic receptor and pertussis-toxin substrate activity codistribute with surface membranes identified by a novel fluorescent-lectin method. The platelet granule fractions did not contain detectable Gi....

Fluoroaluminate had no effect on cAMP levels in cells but inhibited agonist-stimulated cAMP accumulation. In membranes, fluoroaluminate stimulated adenylate cyclase activity between 1 and 10 mM but not at higher concentrations, and it inhibited agonist-stimulated adenylate cyclase activity at concentrations greater than 1 mM. Fluoroaluminate is known to activate Gs and Gi, the guanine nucleotid...

Addition of Staphylococcus aureus alpha-toxin to adult bovine chromaffin cells maintained in primary culture causes permeabilization of cell membrane as shown by the release of intracellular 86Rb+. The alpha-toxin does not provoke a spontaneous release of either catecholamines or chromogranin A, a protein marker of the secretory granule, showing the integrity of the secretory vesicle membrane. ...

The methods currently used for the enumeration of Clostridium perfringens in food are often inadequate because of the rapid loss of viability of this organism when the sample is frozen or refrigerated. A method for estimating the presence of C. perfringens in food which utilizes the hemolytic and lecithinase activities of alpha toxin was developed. The hemolytic activity was measured in hemolys...

Clostridium botulinum type C and D strains recently have been found to produce PLC on egg yolk agar plates. To characterize the gene, enzymatic and biological activities of C. botulinum PLCs (Cb-PLCs), the cb-plc genes from 8 strains were sequenced, and 1 representative gene was cloned and expressed as a recombinant protein. The enzymatic and hemolytic activities of the recombinant Cb-PLC were ...