scholarly journals Measurement of Staphylococcal Enterotoxin B in Serum and Culture Supernatant with a Capture Enzyme-Linked Immunosorbent Assay

2007 ◽  
Vol 14 (9) ◽  
pp. 1094-1101 ◽  
Author(s):  
E. Cook ◽  
X. Wang ◽  
N. Robiou ◽  
B. C. Fries

ABSTRACT Staphylococcal enterotoxin B (SEB) is a select agent because it is a potent mitogen that elicits life-threatening polyclonal T-cell proliferation and cytokine production at very low concentrations. Efforts are in progress to develop therapeutic reagents and vaccines that neutralize or prevent the devastating effects of this toxin. Because of its rapid binding to in vivo receptors, this toxin is difficult to detect in serum. This rapid binding also constitutes a major challenge for the development of effective therapeutic reagents that can neutralize the effects of the toxin in vivo. We have developed a highly sensitive capture enzyme-linked immunosorbent assay that detects SEB in body fluids at very low levels. With this assay, the peak levels of SEB in serum and renal clearance can be measured in mice. After either oral ingestion or nasal inhalation of SEB by mice, this assay documents the transcytosis of SEB across the mucosal membranes into serum within 2 h. Furthermore, this assay was used to compare the SEB levels in different murine models for SEB-induced lethal shock and demonstrated that the coadministration of toxin-enhancing chemicals, such as d-galactosamine and lipopolysaccharide, can alter the peak serum SEB levels. Hence, this assay is a potentially useful tool for the study of the pharmacokinetics of SEB and the effects of potential therapeutic reagents on serum SEB levels.

2009 ◽  
Vol 72 (10) ◽  
pp. 2212-2216 ◽  
Author(s):  
MARYANN PRINCIPATO ◽  
THOMAS BOYLE ◽  
JOYCE NJOROGE ◽  
ROBERT L. JONES ◽  
MICHAEL O'DONNELL

This research was conducted to examine the inherent properties of yogurt contaminated with staphylococcal enterotoxin B (SEB). Two types of yogurts were produced for this study. Type I yogurts were produced by adding SEB at the start of yogurt production, and type II yogurts were produced by adding SEB after the milk base had been boiled. Biochemical characteristics inherent to yogurt, including pH, lactic acid and acetaldehyde concentrations, were analyzed weekly for each batch beginning at a time just after production and throughout a storage period of at least 4 weeks. The presence of toxin during yogurt production did not result in any significant biochemical or physical changes in yogurt. However, we were unable to detect SEB toxin in type I yogurt using a commercially available enzyme-linked immunosorbent assay (ELISA). In contrast, SEB was easily detectable by our ELISA in type II yogurt samples. Higher levels of SEB were recovered from type II yogurt that had been stored for 1 week than from type II yogurt that had been stored for any other length of time. These results indicate that the biochemical characteristics of yogurt did not change significantly (relative to control yogurt) in the presence of either thermally processed SEB or native SEB. However, the ability to detect SEB by ELISA was dependent on whether the toxin had been processed.


1996 ◽  
Vol 64 (11) ◽  
pp. 4567-4573 ◽  
Author(s):  
R Vabulas ◽  
R Bittlingmaier ◽  
K Heeg ◽  
H Wagner ◽  
T Miethke

1996 ◽  
Vol 183 (6) ◽  
pp. 2481-2488 ◽  
Author(s):  
H W Mittrücker ◽  
A Shahinian ◽  
D Bouchard ◽  
T M Kündig ◽  
T W Mak

We used CD28-deficient mice to analyze the importance of CD28 costimulation for the response against Staphylococcal enterotoxin B (SEB) in vivo. CD28 was necessary for the strong expansion of V beta 8+ T cells, but not for deletion. The lack of expansion was not due to a failure of SEB to activate V beta 8+ T cells, as V beta 8+ T cells from both CD28-/- and CD28+/+ mice showed similar phenotypic changes within the first 24 h after SEB injection and cell cycle analysis showed that an equal percentage of V beta 8+ T cells started to proliferate. However, the phenotype and the state of proliferation of V beta 8+ T cells was different at later time points. Furthermore, in CD28-/- mice injection with SEB led to rapid induction of unresponsiveness in SEB responsive T cells, indicated by a drastic reduction of proliferation after secondary SEB stimulation in vitro. Unresponsiveness could also be demonstrated in vivo, as CD28-/- mice produced only marginal amounts of TNF alpha after rechallenge with SEB. In addition CD28-/- mice were protected against a lethal toxic shock induced by a second injection with SEB. Our results indicate that CD28 costimulation is crucial for the T cell-mediated toxicity of SEB and demonstrate that T cell stimulation in the absence of CD28 costimulation induces unresponsiveness in vivo.


2019 ◽  
Vol 431 (21) ◽  
pp. 4354-4367 ◽  
Author(s):  
Gang Chen ◽  
Hatice Karauzum ◽  
Hua Long ◽  
Danielle Carranza ◽  
Frederick W. Holtsberg ◽  
...  

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