Isolation, characterisation, and biocontrol application of novel Clostridium perfringens phages on chicken meat.

Clostridium perfringens is a significant foodborne pathogen in the poultry industry, creating a need for novel antimicrobial interventions. This study reports the isolation and comparative biological characterisation of three novel bacteriophages, vB_CpS_CP3C, vB_CpS_CP4C, and vB_CpS_CP5S, identified as dsDNA viruses with siphoviral morphology, belonging to the class Caudoviricetes. The phages exhibited distinct stability profiles: CP3C and CP5S were stable up to 60 °C and across functional pH ranges (pH 5-8 and 4-7, respectively), while CP4C was thermolabile above 25 °C. Lytic dynamics also varied significantly; latent periods were 15 min (CP4C), 20 min (CP3C), and 20 min (CP5S), while average burst sizes were 308 (CP3C), 206 (CP4C), and 73 (CP5S) PFU/cell. Host range analysis against 15 C. perfringens strains revealed all three phages to be highly specific, lysing only the ATCC 13124 strain. In an in vitro challenge on chicken meat at 37 °C, treatments with phages CP3C and CP4C did not produce a significant reduction in bacterial counts, whereas CP5S achieved a significant (p < 0.01) 0.6-log reduction after 48 h compared to the untreated control. Although all isolates share the limitation of a narrow host range, the superior thermal and pH stability combined with its unique biocontrol efficacy on a food matrix identify CP5S as the most promising candidate for future investigation.