Sensitive Detection of Bacillus anthracis Using a Binding Protein Originating from γ-Phage

Detection of biological weapons is a primary concern in force protection, treaty verification, and safeguarding civilian populations against domestic terrorism. One great concern is the detection of Bacillus anthracis, the causative agent of anthrax. Therefore, there is a pressing need to develop novel methods for rapid, simple, and precise detection of B. anthracis. Here, we report that the C-terminal region of γ-phage lysin protein (PlyG) binds specifically to the cell wall of B. anthracis and the recombinant protein corresponding to this region (positions, 156–233), PlyGB, is available as a bioprobe for detection of B. anthracis. Our detection method, based on a membrane direct blot assay using recombinant PlyGB, was more rapid and sensitive than the γ-phage test and was simpler and more inexpensive than genetic methods such as PCR, or immunological methods using specific antibodies. Furthermore, its specificity was comparable to the γ-phage test. PlyGB is applicable in conventional methods instead of antibodies and could be a potent tool for detection of B. anthracis.