The PlyB Endolysin of Bacteriophage vB_BanS_Bcp1 Exhibits Broad-Spectrum Bactericidal Activity against Bacillus cereus Sensu Lato Isolates

Organisms of theBacillus cereus sensu lato lineage are ubiquitous in the environment and are responsible for toxin-mediated infections ranging from severe food poisoning (B. cereus sensu stricto ) to anthrax (Bacillus anthracis ). The increasing incidence of many of these infections, combined with the specter of antibiotic resistance, has created a need for novel antimicrobials with potent activity, including bacteriophages (or phages) and phage-encoded products (i.e., endolysins). In this study, we describe a broadly infective phage, Bcp1, and its encoded endolysin, PlyB, which exhibited a rapidly bacteriolytic effect against allB. cereus sensu lato isolates tested with no evidence of evolving resistance. Importantly, PlyB was highly efficacious in a mouse model of lethal bacteremia withB. anthracis . Both the Bcp1 phage and the PlyB endolysin represent novel mechanisms of action compared to antibiotics, with potential applications to address the evolving problem of antimicrobial resistance.