Work

A novel lytic phage with potent efficacy against Bacillus cereus, its biofilms and spores, and biocontrol potential in food matrices

Year: 2026

Type: article

Abstract: To address the severe threat posed by Bacillus cereus ( B. cereus ) and its spores to food safety, this study isolated and characterized a novel lytic phage, WAH2, using a multidrug-resistant B. cereus strain as the host. Morphological observation showed that WAH2 had an icosahedral head and a contractile tail. The phage lysed 7 of 51 (13.7%) B. cereus strains covering 3 sequence types. Biological characterization showed that the optimal multiplicity of infection of WAH2 was 0.0001. It remained stable at 4–45°C, pH 5–11, and 2%–10% NaCl. Its latent period was 30 min, and the burst size was 208 PFU/cell. Genome analysis showed that WAH2 possesses a linear double-stranded DNA genome of 158991 bp with a GC content of 37.96%. It encodes 284 open reading frames and 6 tRNA genes. No antibiotic resistance genes, virulence factors, or lysogeny-related elements were detected. WAH2 was classified as a novel species within the genus Bastillevirus , family Herelleviridae . In vitro assays showed that WAH2 strongly inhibited host bacterial growth (no regrowth within 36 h), significantly reduced biofilm formation and disrupted mature biofilms, and effectively inhibited the outgrowth of germinated spores. Importantly, in food matrices such as milk, rice, and pork, WAH2 significantly reduced or completely eliminated B. cereus in a dose- and time-dependent manner at both 25 and 4°C, with no regrowth observed. In TSB and milk, WAH2 persisted for 120 h without detectable resistant survivors. In summary, WAH2 is a safe, efficient, and promising phage that can serve as a biocontrol candidate against B. cereus in food.

Source: Current Research in Food Science

DOI: 10.1016/j.crfs.2026.101603