Rapid Detection of Bacillus anthracis in Complex Food Matrices Using Phage-Mediated Bioluminescence

Bacillus anthracis, the causative agent of anthrax, is considered a high-priority agent that may be used in a food-related terrorist attack because it can be contracted by ingestion and it also forms spores with heat and chemical resistance. Thus, novel surveillance methodologies to detect B. anthracis on adulterated foods are important for bioterrorism preparedness. We describe the development of a phage-based bioluminescence assay for the detection of B. anthracis on deliberately contaminated foods. We previously engineered the B. anthracis phage Wβ with genes encoding bacterial luciferase (luxA and luxB) to create a “light-tagged” reporter (Wβ::luxAB) that is able to rapidly detect B. anthracis by transducing a bioluminescent signal response. Here, we investigate the ability of Wβ::luxAB to detect B. anthracis Sterne, an attenuated select agent strain, in inoculated food (ground beef) and milk (2%, baby formula, and half and half) matrices after incubation with spores for 72 h at 4°C as per AOAC testin...