Bacteriophage P100 for control of Listeria monocytogenes in foods: Genome sequence, bioinformatic analyses, oral toxicity study, and application Original paper

What was studied?

This study investigated the bacteriophage P100 for its potential use in controlling Listeria monocytogenes in food products, particularly in soft cheeses. The research focused on several aspects: the genome sequence of the P100 phage, bioinformatic analyses of its genes, an oral toxicity study in rats, and its effectiveness in reducing Listeria contamination on food surfaces. The study provided a comprehensive evaluation of the safety and efficacy of using P100 as a biocontrol agent for foodborne pathogens.

Who was studied?

The study focused on bacteriophage P100, a virulent, lytic phage capable of infecting a broad range of Listeria strains, including Listeria monocytogenes. It also involved testing the bacteriophage’s impact on a rat model for toxicity, as well as its application on artificially contaminated soft cheese surfaces. Listeria monocytogenes was the target pathogen for these experiments.

What were the most important findings?

The key findings of this study include the successful sequencing of the P100 phage genome, which revealed no homology with known virulence factors, toxins, or allergens, indicating that it is safe for use in food. A repeated-dose oral toxicity study in rats showed that P100 did not result in any adverse effects, such as abnormal histological changes or mortality, confirming its safety for human consumption. The study also demonstrated that applying P100 to surface-ripened soft cheese effectively reduced Listeria monocytogenes counts. Depending on the phage concentration and application frequency, a significant reduction (at least 3.5 logs) or even complete eradication of Listeria was achieved. Importantly, no phage resistance was observed, and P100 did not negatively affect the natural microbial flora or the ripening process of the cheese.

What are the greatest implications of this study?

The study highlights the potential of P100 as a safe and effective biocontrol agent for reducing Listeria monocytogenes contamination in food products, particularly in ready-to-eat items like soft cheeses. The findings support the use of P100 as a food additive for food safety, offering an alternative to traditional antimicrobial treatments that may disrupt food microbiomes or lead to resistance. This phage’s broad host range and effectiveness in eradicating Listeria provide an innovative approach to controlling foodborne pathogens without the harmful side effects typically associated with chemical preservatives. Further exploration of its application in other food products and production environments could significantly enhance food safety.