Spores of Bacillus anthracis, the causative agent of anthrax, are enclosed by an exosporium, which consists of a basal layer surrounded by a nap of hair-like filaments. The major structural component of the filaments is called BclA, which comprises a central collagen-like region (CLR) and a globular C-terminal domain. Here, the entire CLR coding sequence of BclA was removed, and the resulting protein (tBclA) produced in Escherichia coli. The crystallographic structure of tBclA was determined to 1.35 A resolution, and consists of an all-beta structure with a TNF-like jelly fold topology (12 beta-strands which form 2 beta-sheets of five strands each) consistent with previous studies on wild-type BclA. These globular domains are tightly packed into trimeric structures (surface shape complementarity; S (c) = 0.83), demonstrating that formation of the core structure of BclA is independent of the anchoring collagen-like region. A polyclonal antibody raised against tBclA recognized B. anthracis spores directly, and showed little cross-reactivity (<10%) with the spores of the closely related species Bacillus cereus and Bacillus thuringiensis, when compared to two other polyclonal antibodies raised against B. anthracis spore extracts and inactivated spores. The tBclA protein was used to purify a pool of specific antibodies from bovine colostrum whey samples from cows inoculated with the Sterne strain anthrax vaccine, which also showed reactivity with B. anthracis spores. Together, these results demonstrate that tBclA provides a safer and more effective way to the production and purification of antibodies with high binding affinity for B. anthracis spores. Biotechnol. Bioeng. 2008;99: 774-782. (c) 2007 Wiley Periodicals, Inc.

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The use of biological agents has generally been confined to military‐led conflicts. However, there has been an increase in non‐state‐based terrorism, including the use of asymmetric warfare, such as biological agents in the past few decades. Thus, it is becoming increasingly important to consider strategies for preventing and preparing for attacks by insurgents, such as the development of pre‐ and post‐exposure medical countermeasures. There are a wide range of prophylactics and treatments being investigated to combat the effects of biological agents. These include antibiotics (for both conventional and unconventional use), antibodies, anti‐virals, immunomodulators, nucleic acids (analogues, antisense, ribozymes and DNAzymes), bacteriophage therapy and micro‐encapsulation. While vaccines are commercially available for the prevention of anthrax, cholera, plague, Q fever and smallpox, there are no licensed vaccines available for use in the case of botulinum toxins, viral encephalitis, melioidosis or ricin. Antibiotics are still recommended as the mainstay treatment following exposure to anthrax, plague, Q fever and melioidosis. Anti‐toxin therapy and anti‐virals may be used in the case of botulinum toxins or smallpox respectively. However, supportive care is the only, or mainstay, post‐exposure treatment for cholera, viral encephalitis and ricin – a recommendation that has not changed in decades. Indeed, with the difficulty that antibiotic resistance poses, the development and further evaluation of techniques and atypical pharmaceuticals are fundamental to the development of prophylaxis and post‐exposure treatment options. The aim of this review is to present an update on prophylaxis and post‐exposure treatment recommendations and research initiatives for biological agents in the open literature from 2007 to 2009.

Ricin is a toxin that can be easily extracted from seeds of Ricinus communis plants. Ricin is considered to be a major bio-threat as it can be freely and easily acquired in large quantities. A deliberate release of such toxin in civilian populations would very likely overwhelm existing public health systems, resulting in public fear and social unrest. There is currently no commercially available or FDA-approved prophylaxis such as vaccines, or therapeutic antitoxins or antidotes, available for ricin intoxication. Patient treatment is typically supportive care based on symptoms, often designed to reinforce the body's natural response. This paper describes the development and validation of a robust ELISA test kit, which can be used to screen for ricin in biological specimens such as whole blood and faeces. Faecal specimens are shown in this study to have better diagnostic sensitivity and a wider diagnostic window compared to whole blood. From these results, it is concluded that faeces is the most suitable clinical specimen for diagnosis of ricin poisoning via the oral route. The ELISA test kit can also detect ricin in environmental samples. An advantage of this ELISA kit over other commercial off-the-shelf (COTS) detection kits currently on the market that are developed to screen environmental samples only is its ability to diagnose ricin poisoning from clinical specimens as well as detect ricin from environmental samples.