Postexposure Recovery and Analysis of Biological Agent in a Simulated Biothreat Scenario Using Tandem Mass Spectrometry.

Some pathogens and toxins have the potential to be used as weapons of mass destruction and instigate population-based fear. Rapid, sensitive, and unambiguous identification of biothreat agents is of paramount importance for confirmation of the event and to mitigate the direct and indirect damages to public health and resources. Although there are several potential dissemination scenarios to describe an attack with a biological weapon, artificially generated bioaerosol is of the greatest concern from a bioterrorism or warfare perspective, potentially capable of causing mass destruction to a civilian or military population by inhalation of toxic bioaerosol. The present investigation proposes methodologies for recovery of biological agent followed by an off-site unambiguous detection using tandem mass spectrometry, in a postattack situation. We envisaged a biothreat scenario wherein the polydispersed bioaerosol is disseminated in bulk over any geographical setting. The larger particles (>5 μm in diameter) of bioaerosol settle and bind to various surfaces depending on the geographical setting. Recovery of agent was optimized from foliage, sand, and glass in a simulated biothreat scenario using bovine serum albumin (BSA). The recovered agents were shown to be amenable to detection by a downstream tandem MS analysis. Applicability of the proposed methodology was demonstrated in validation experiments for the recovery and detection of toxin and bacterial agents. The use of cleaner matrices (foliage, exposed smooth surfaces, sand) is recommended for retrospective verification of agent in a biothreat scenario.