Botulinum neurotoxins (BoNTs) are the most potent natural toxins known. The family of BoNTs comprises seven antigenically distinct serotypes (A to G) that are produced by various toxigenic strains of spore-forming anaerobic Clostridium botulinum. They act as metalloproteinases that enter peripheral cholinergic nerve terminals and cleave proteins that are crucial components of the neuroexocytosis apparatus, causing a persistent but reversible inhibition of neurotransmitter release resulting in flaccid muscle paralysis.

Apart from being the sole causative agent of the deadly food poisoning disease, botulism, BoNTs pose a major biological warfare threat due to their extreme toxicity and easy production. Interestingly they also serve as powerful tools to treat an ever expanding list of medical conditions. A better understanding of the structure-function relationship of clostridial neurotoxins will not only help decipher their molecular mode of action but will also provide a greater understanding of the potential use of their individual domains in answering more fundamental questions of neuroexocytosis. It is also critical for designing effective specific inhibitors to counter botulism biothreat, and for the development of new therapeutics.

from Kukreja and Singh in Microbial Toxins: Current Research and Future Trends

Further reading:

1. Microbial Toxins
2. Clostridia: Molecular Biology in the Post-genomic Era

Labels: bacteria, biodefense, botulism, clostridia, clostridium, toxin, toxins

from Christina Egan, Nick M. Cirino and Kimberlee A. Musser in Real-Time PCR: Current Technology and Applications

With the public's reawakened concern regarding use of biological agents as weapons, the rapid detection, discrimination, and identification of pathogenic organisms and toxins has become a priority for state and federal government agencies. High confidence, cost effective, and near real-time diagnostic methods are essential to protecting national health security whether the target is public health, agriculture, commodities, or water supply infrastructures. While culture-based methods have been, and will likely remain, the gold standard for microbiological diagnostics, PCR-based tests offer significant advantages in sensitivity, specificity, speed and data richness that make them invaluable to diagnostic laboratories. We describe the application of real-time PCR methods in biodefense and discuss the use of real-time PCR in biodefense in terms of general workflow and processing considerations, clinical diagnostic applications, environmental diagnostic applications, and multiplex screening. Real-time PCR assays can be either quantitative (qPCR) or qualitative, depending on whether a standard curve is included with the analytical run. Most diagnostic and biodefense applications utilise the qualitative nature of real-time PCR as a detection platform. We consider the future uses and anticipated advances in real-time PCR applications as related to biodefense.

Further reading: Real-Time PCR: Current Technology and Applications

Labels: biodefense, PCR, qPCR, real-time PCR