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Updated: Jul 7, 2025
Bacteriophage Effectiveness for Biocontrol of Foodborne Pathogens Evaluated via High-Throughput Settings
Published on: August 19, 2021
Psychrophilic phage phiGM22-3 efficiently controls Pseudomonas fluorescens contamination in cold-stored milk
Xuying Qin1, Mengxin Gong1, Yutong Li1
1Key Laboratory of Industrial Microbiology of the Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China.
Abstract:
Pseudomonas fluorescens is a common spoilage causing microbe found in milk. Antibiotic preservatives may cause emergence of multidrug resistance, posing food safety related risks to public health. Phage treatment may be used as an alternative to antibiotics in controlling P. fluorescens contaminations. Here we reported that P. fluorescens phage phiGM22-3 reproduced rapidly over a broad temperature range of 4 through 30°C, and the optimum growth of phiGM22-3 occurred at 10°C, indicating that it was a psychrophilic virus. Genome analysis revealed that phiGM22-3 has a genome of 42,662 bp with an identical terminal direct repeat sequence of 328 bp and encodes 58 predicted proteins. Evidence revealed that phiGM22-3 recognized lipopolysaccharides (LPS) as receptor for infection. Additionally, two phage mutants phiMX2 and phiMX8 with different host ranges were identified in the phiGM22-3 population. Phage killing efficiency of P. fluorescens cells artificially inoculated in milk was evaluated. Phage phiGM22-3 and the cocktails containing phiMX2 and phiMX8 can lyse almost 100% bacterial cells at 4°C within 24 h. Taken together, our data indicated that the psychrophilic virus phiGM22-3 and its two mutants can efficiently inhibit bacteria growth at 4°C, showing a great potential to be used as alternatives to conventional antibiotics against P. fluorescens in refrigerated foods.
Insights
A novel bacteriophage, phiGM22-3, effectively controls Pseudomonas fluorescens spoilage in milk at low temperatures. This psychrophilic phage and its mutants show promise as natural alternatives to antibiotics in food safety.
Area of Science:
- Food microbiology
- Bacteriophage research
- Antimicrobial strategies
Background:
- Pseudomonas fluorescens is a common milk spoilage bacterium.
- Antibiotic use raises concerns about multidrug resistance and food safety.
- Bacteriophage therapy presents a potential alternative to antibiotics.
Purpose of the Study:
- To investigate the efficacy of Pseudomonas fluorescens phage phiGM22-3 as a biocontrol agent.
- To characterize the properties of the psychrophilic phage phiGM22-3 and its mutants.
- To evaluate phage treatment for controlling P. fluorescens in refrigerated milk.
Main Methods:
- Isolation and characterization of P. fluorescens phage phiGM22-3.
- Genome sequencing and analysis of phiGM22-3.
- Identification and characterization of phage mutants phiMX2 and phiMX8.
- Assessment of phage lytic activity against P. fluorescens in milk at 4°C.
Main Results:
- Phage phiGM22-3 exhibits optimal growth at 10°C, classifying it as a psychrophilic virus.
- The phage genome is 42,662 bp, encoding 58 proteins, and uses lipopolysaccharides (LPS) as receptors.
- Phage phiGM22-3 and its mutants (phiMX2, phiMX8) achieved nearly 100% bacterial lysis within 24 hours at 4°C.
Conclusions:
- The psychrophilic phage phiGM22-3 and its mutants demonstrate high efficiency in inhibiting P. fluorescens at refrigeration temperatures.
- These phages represent a promising, natural alternative to conventional antibiotics for controlling P. fluorescens in refrigerated foods.
- This research supports the application of phage therapy for enhancing food safety and reducing reliance on antibiotics.
