Genomic and Biological Insights of Bacteriophage ΦBc24 Targeting Bacillus cereus.
Nam Khang Tran, Pham Thi Lanh, Trang Trinh Thu, Man Hong Phuoc, Nguyen Dinh Duy, Vu Thi Hien, Dong Van Quyen
Abstract
Open AccessFoodborne illnesses associated with Bacillus cereus represent a persistent public health concern. In this study, we described the isolation and characterization of a novel bacteriophage, ΦBc24, from mud samples, which showed lytic activity against foodborne pathogen B. cereus. Transmission electron microscopy revealed that ΦBc24 exhibited a myovirus morphotype. Biological assays demonstrated that its narrow host range was restricted to B. cereus strains and efficient lytic activity, characterized by a latent period of 10 min and a burst size of 40 PFU per infected cell. The phage exhibited high physicochemical stability, tolerating pH values of 2-12, temperatures of 4-50 °C, salinity up to 1 M NaCl, and ultraviolet exposure, while effectively suppressing host bacterial growth for up to six hours. Whole-genome sequencing showed that phage ΦBc24 possessed a double-stranded DNA genome of 160,311 bp, with 39.48% GC content, and 269 predicted open reading frames (ORFs). Remarkably, 11 tRNA genes were identified, whereas no genes associated with lysogeny, virulence, or antimicrobial resistance were detected. Phylogenetic analysis suggested that ΦBc24 belongs to the genus Caeruleovirus, subfamily Bastillevirinae, family Herelleviridae. Taken together, these results highlight the biological robustness and genomic safety of ΦBc24, supporting its potential as a biocontrol candidate against the foodborne pathogen B. cereus.