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The Host R-M Systems Change the Host Range of Staphylococcus Phage EBHT
Henni Tuomala1, Julia Holtel2, Melina Markkanen3
1Research Program Unit, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
Microbiologyopen
|November 28, 2025
Summary
Bacteriophage production hosts significantly impact phage host specificity due to bacterial restriction-modification systems. Optimal phage production requires careful selection of hosts, considering these systems for therapeutic applications.
Area of Science:
- Bacteriophage biology
- Microbial genetics
- Phage therapy
Background:
- Therapeutic bacteriophages require production in well-defined bacterial strains.
- Phage-host interactions during production can differ from clinical settings.
- Bacterial restriction-modification (R-M) systems can influence phage characteristics.
Purpose of the Study:
- To characterize the lytic Staphylococcus aureus-specific phage vB_SauP_EBHT (EBHT).
- To investigate the impact of different production hosts on EBHT's host specificity.
- To elucidate the role of bacterial R-M systems in observed phage alterations.
Main Methods:
- Characterization of phage EBHT produced in two different bacterial hosts (DSM 104437 and 19A2).
- Analysis of phage genome, proteome, structure, and adsorption efficiency.
- Investigation of host restriction-modification systems' role in phage host range.
Main Results:
- Phage EBHT exhibited altered host specificity when produced in alternative host 19A2 compared to isolation host DSM 104437.
- No changes were observed in the phage's genome, proteome, structure, or adsorption efficiency.
- Altered host range was attributed to differential methylation patterns of the EBHT genome by host R-M systems.
- Host 19A2 yielded a higher burst size but resulted in a narrower phage host range.
Conclusions:
- The most efficient phage production host may not be the most optimal for therapeutic applications.
- Bacterial restriction-modification systems are critical factors in selecting optimal phage production hosts.
- Understanding host R-M systems is essential for consistent and effective phage therapy development.
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