Staphylococcal toxins

The following sections of this review will now transition into a unique group of protein toxins, the SEs and TSST-1. These proteins secreted by S. aureus vcovk in a different fashion versus the aforementioned binary toxins. In fact, these staphylococcal toxins do not enter a cell and do not directly injure the targeted cell surface. Toxin damage is insidiously indirect and caused by an over zealous response executed by the host s immune system. 

The coupling of superantigen—major histocompatibility complex class II to T-cell receptor swifdy results in cell-signaling cascades. ° These staphylococcal toxins can increase levels of phosphatidyl inositol from quiescent T cells, such as other mitogens, as well as elicit intracellular Ca movement that activates the protein kinase C (PKC) pathway important for interleukin-2 (IL-2) expression. " IL-2 is intimately linked to T-cell proliferation. In addition to the PKC pathway, the protein tyrosine kinase (PTK) pathway is also activated by superantigens, leading to elevated expression of various proinflammatory cytokines. Staphylococcal superantigens also potently activate transcriptional factors NF-/IB (nuclear factor kappa B) and AP-1 (activator protein-1), which subsequently elicit the synthesis of proinflammatory cytokines. " " ... 

Nedelkov, D., Rasooly, A., and Nelson, R. W. (2000). Multitoxin biosensor-mass spectrometry analysis A new approach for rapid, real-time, sensitive analysis of staphylococcal toxins in food. Int.. Food Microbiol. 60,1-13. 

The staphylococcal toxin must be separated from food constituents and concentrated to detect trace amounts. The toxin is then identified by specific precipitation with antiserum as follows (1) the selective adsorption of the enterotoxin from an extract of the food onto ion exchange resins and (2) the use of physical and chemical procedures for the selective removal of food constituents leaving the enterotoxin in solution. More recently rapid methods based on monoclonal antibodies (e.g., enzyme-linked immunosorbent assay, reverse passive latex agglutination) have been developed for detecting very low levels of enterotoxin in food. 

The most frequently used methods for detection of staphylococcal toxins are ELISA, reverse passive latex agglutination (Igarashi et al. 1986 Park and Szabo 1986 Rose et al. 1989) and radioimmunological assays (Thompson et al. 1986). The methods which directly detect toxins are laborious and obviously vary with enviromnental parameters, affecting the expression of the gene responsible for the toxin production. 

Hofer MF, Harbeck RJ, Schlievert PM, Leung DYM Staphylococcal toxins augment specific IgE responses by atopic patients exposed to allergen. J Invest Dermatol 1999 112 171-176. 

Kappler J, Kotzin B, Herron L, Gelfand EW, Bigler RD, Boylston A, Carrel S, Posnett DN, Choi Y, Marrack P V beta-specific stimulation of human T cells by staphylococcal toxins. Science 1989 244 811-813. 

G. J. Silverman et al., The dual phases of the response to a neonatal exposure to a VH family-restricted staphylococcal B cell superantigen, Journal of Immunology, 161, 1998, 5720-32 C. S. Goodyear and G. J. Silverman, Death by a B cell superantigen in vivo VH-targeted apoptotic supraclonal B cell deletion by a staphylococcal toxin, Journal of Experimental Medicine, 197, 2003, 1125-39. 

Data sources (1) Kappler J, Kotzin B, Herron L, et al. Vp-spe-cific stimulation of human T cells by staphylococcal toxins. Science. 1989 244 811-813. (2) Marrack P, Kappler J. The staphylococcal enterotoxins and their relatives. Science. 1990 248 705-711. (3) Champagne E, Huchenq A, Sevin J, Casternan N, Rubin B. An alternative method for T-cell receptor repertoire analysis Clustering of human V-beta subfamilies selected in responses to staphylococcal enterotoxins B and E. Mol Immunol. 1993 30(10) 877 886. 

Takei S, Arora YK, Walker SM. Intravenous immunoglobulin contains specific antibodies inhibitory to activation of T cells by staphylococcal toxin superantigens. J Clin Invest. 1993 91 602-607. 

The toxins produced by bacteria vary in their sensitivity to heat. The staphylococcal toxin which causes vomiting is not inactivated even if it is boiled. Fortunately, the potent toxin that causes botulism is completely inactivated by boiling. 

II. Toxic dose. The toxic dose depends on the type of bacteria or toxin and its concentration in the ingested food, as well as individual susceptibility or resistance. Some of the preformed toxins (eg, staphylococcal toxin) are heat resistant and once in the food are not removed by cooking or boiling. 

Staphylococcal Toxins Kansas State/Iandolo Preclinical... 

Baker HM, Basu I, Chung MC et al. Crystal structures of the staphylococcal toxin SSL5 in complex with sialyl Lewis X reveal a conserved binding site that shares common features with viral and bacterial sialic acid binding proteins. J Mol Biol 2007 374 1298-1308. 

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