More's the Same-Multiple Hosts Do Not Select for Broader Host Range Phages

Area of Science:

• Microbiology
• Virology
• Bacteriophage Research

Background:

• Bacteriophage (phage) host range is crucial for phage therapy applications.
• Broader host range phages are desirable for targeting diverse pathogen strains.
• A common assumption is that isolating phages using multiple hosts enhances the discovery of broader host range phages.

Purpose of the Study:

• To investigate whether isolating phages using multiple hosts increases the likelihood of obtaining broader host range phages.
• To compare the host ranges of phages isolated using single versus multiple host strategies.
• To evaluate the efficacy of multiple-host isolation for identifying phages with expanded host ranges.

Main Methods:

• Utilized a Bacillus cereus group system for phage isolation and characterization.
• Compared the host ranges of phages isolated using a single host versus four different hosts.
• Quantified and analyzed the breadth of host ranges for all isolated phages.

Main Results:

• No significant difference was observed in the breadth of host ranges between phages isolated using one host versus four hosts.
• Both narrow and broader host range phages were equally likely to be isolated irrespective of the isolation procedure.
• The study found that multiple hosts during isolation do not consistently yield broader host range phages.

Conclusions:

• The common belief that multiple-host isolation increases the chances of obtaining broader host range phages is not supported by this study.
• While other methods like sequential host isolation can yield broader host range phages, multiple-host isolation is not a reliable strategy for this purpose.
• Alternative methods should be considered for reliably isolating broader host range phages for therapeutic applications.