In vitro-activated charcoal binding of staphylococcal enterotoxin B

Staphylococcal enterotoxin B (SEB) is a CDC category B bioterror agent that may cause significant morbidity. We assessed the in vitro binding of SEB by activated charcoal (AC).

Aqueous solutions of SEB at three concentrations (0.4, 2 and 10 mcg/mL) were combined in volume rations of 3:1, 6:1, and 12:1 with AC at three concentrations (62.5, 125, and 250 mg/mL) or left untreated as control samples. Subsequently, each sample was tested with a qualitative SEB immunoassay to detect the presence of SEB at concentrations of >12.5 ng/mL.

SEB was detectable in each untreated control solution. SEB was undetectable in the 2 mcg/mL and 0.4 mcg/mL solutions after treatment with AC in all quantities. SEB was detected in the 10 mcg/mL solution after combination with all three concentrations of AC. The difference in assay results between charcoal treated and untreated pairs was statistically significant.

At ratios of 3:1 and above, SEB was adsorbed by AC when combined in the manner described in concentrations of 2 mcg/mL and 0.4 mg/mL. In a quantity of 10 mcg/mL complete charcoal binding of SEB did not occur with any ratio of AC used. These results support a role for AC in treating patients exposed to SEB or purifying liquids or gases containing SEB.