SGER: Inactivation of Bacillus Spores Using Antimicrobial Peptides

Worcester Polytechnic Institute, Worcester MA

Investigators

Abstract

Terri A Camesano Worcester Polytechnic Institute SGER: Inactivation of Bacillus Spores Using Antimicrobial Peptides Intellectual Merit Bacterial spores are the most resistant life forms known, whose dormancy and resistance are attributed to their nanoscale multi-compartmental structure and morphology. The inner cell membrane encapsulating the DNA and other cellular contents is protected from the external environment by nearly 100 nm barrier of a polymer layer and protein coat. Spores such as Bacillus anthracis are especially problematic, because they have been used as bioterrorism agents and their potential for future abuse remains. In addition to being very difficult to inactivate, Bacillus spores are easily spread through the environment and can readily contaminate a large area from a single source. Although spores are not infective, with proper stimuli, the spores transform from their dormant state to a virulent pathogenic state via a multi−step process of which germination is the first. According to current understanding of spore inactivation, it is believed that germination must occur before spores can be killed by anti-sporal agents, with a few exceptions such as dodecylamine (DDA), although the mechanism of the deactivation is not understood. Currently, there are no adequate methods for spore inactivation that will work in all environments. For example, while bleach and water are commonly used for spore inactivation, their effectiveness is greatly reduced by the presence of organic materials, meaning that this technique is much more effective in the laboratory than it would be in a field environment. For the first time, we have demonstrated in preliminary experiments that a naturally occurring antimicrobial peptide can inactivate Bacillus spores, and this occurs even in the absence of a chemical germinant. Broader Impacts The broader impacts of this work are due to the societal need for new methods of spore deactivation, as well as, the potential to train students and affect outreach to K-12 teachers. This work has a clear societal benefit since there are currently no effective methods for spore detection and inactivation that will work for different types of surfaces and under environmentally-relevant conditions, such as in the presence of organic matter.