Phage-mediated bioluminescent detection of Bacillus anthracis

Aims:  Bacillus anthracis , the causative agent of anthrax, is a serious human pathogen. The aim of this study was to provide the proof of principle results for the development of a 'bioluminescent' reporter bacteriophage that was capable of specifically detecting B. anthracis .
Methods and Results:  The reporter phage was engineered by integrating the bacterial luxA and luxB reporter genes into a nonessential region of the lysogenic Wβ phage genome. This resulted in a phage that was capable of specifically infecting and conferring a bioluminescent phenotype to B. anthracis viable cells. No processing or cell preparation was required; the phage and cells were simply mixed, and the samples were analysed for bioluminescence. A bioluminescent signal was evident after 16 min postinfection of vegetative cells. The strength and time required to generate the signal was dependent on the number of cells present. Nevertheless, 10³ CFU ml⁻¹ was detectable within 60 min. The utility of the bioluminescent phage was analysed using spores as the starting material. The Wβ:: luxAB phage was able to transduce a bioluminescent signal to germinating spores within 60 min.
Conclusions:  This proof of principle study demonstrates that the reporter phage displays promise as a tool for the rapid detection of B. anthracis .
Significance and Impact of the Study:  The new methodology offers the potential for the detection of viable cells from either environmental or clinical samples.