Novel Enterococcus phages identified through comprehensive screening to control contamination in chicken meat

Area of Science:

• Microbiology
• Food Science
• Antimicrobial Resistance

Background:

• Antibiotic-resistant Enterococcus faecalis and E. faecium are significant food contaminants, posing risks to food safety and facilitating antimicrobial resistance (AMR) spread.
• Poultry products are particularly susceptible to Enterococcus contamination, necessitating effective control strategies.

Purpose of the Study:

• To isolate and characterize Enterococcus-targeting phages from environmental sources.
• To evaluate the biocontrol efficacy of selected phages against Enterococcus in a chicken wing food model.

Main Methods:

• Environmental screening yielded 45 Enterococcus-specific phages; two (Efs.1 1-1 and Efm 3-10) were selected for detailed analysis.
• Phage characterization included transmission electron microscopy, whole-genome sequencing, stability assays (pH, temperature), and storage stability tests.
• In vitro and chicken wing model assays assessed phage efficacy in reducing Enterococcus populations.

Main Results:

• Two novel lytic phages, Efs.1 1-1 and Efm 3-10, were identified with siphovirus morphology, short latent periods, and high burst sizes.
• Genomic analysis confirmed complete, non-virulent, non-lysogenic genomes lacking AMR genes. Phages showed stability at pH 4 and up to 60°C for 1 hour.
• Phage treatment completely eliminated Enterococcus in vitro and maintained counts below detection limits in the chicken wing model during refrigerated storage, achieving significant log reductions.

Conclusions:

• Novel lytic phages Efs.1 1-1 and Efm 3-10 possess robust stability and potent antibacterial activity.
• These phages represent promising biocontrol agents for mitigating Enterococcus contamination in poultry meat, thereby enhancing food safety.