Strategies for Editing Virulent Staphylococcal Phages Using CRISPR-Cas10

Area of Science:

• Microbiology
• Genetics
• Virology

Background:

• Staphylococci are common bacteria causing antibiotic-resistant infections.
• Virulent staphylococcal phages are potential antibiotic alternatives but pose risks due to unknown gene functions and genetic engineering challenges.
• CRISPR-Cas10 systems in staphylococci offer a potential tool for phage genome engineering.

Purpose of the Study:

• To investigate the efficacy of Staphylococcus epidermidis CRISPR-Cas10 systems against virulent staphylococcal phages.
• To develop and demonstrate a method for engineering virulent staphylococcal phages using CRISPR-Cas10.
• To enable systematic study of phage genes and design of targeted phage-based antimicrobials.

Main Methods:

• Assessed CRISPR-Cas10 immunity against various virulent staphylococcal phages in Staphylococcus epidermidis.
• Developed a two-step phage genome editing strategy utilizing host homologous recombination.
• Adapted methods for editing toxic phage genes and targeting phages in CRISPR-deficient staphylococci.

Main Results:

• The native CRISPR-Cas10 system in Staphylococcus epidermidis demonstrated strong immunity against diverse virulent staphylococcal phages.
• A versatile two-step genetic engineering approach for virulent phages was successfully established.
• The developed tools allow for the modification of phage genes and the targeting of phages in different staphylococcal strains.

Conclusions:

• CRISPR-Cas10 systems are effective against virulent staphylococcal phages and can be leveraged for phage genome editing.
• The developed genetic tools facilitate the investigation of unknown phage functions and the creation of precisely engineered phage antimicrobials.
• This work paves the way for safer and more effective phage-based therapies against Staphylococcus infections.