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Updated: Nov 18, 2025

Precise Phage Mutagenesis with NgTET-Assisted CRISPR-Cas Systems
Published on: October 14, 2025
The endless battle between phages and CRISPR-Cas systems in Streptococcus thermophilus
Cécile Philippe1,2, Sylvain Moineau1,2,3
1Département de biochimie, de microbiologie, et de bio-informatique, Faculté des sciences et de génie, Université Laval, Québec, QC G1V 0A6, Canada.
Abstract:
This review describes the contribution of basic research on phage-bacteria interactions to the understanding of CRISPR-Cas systems and their various applications. It focuses on the natural function of CRISPR-Cas systems as adaptive defense mechanisms against mobile genetic elements such as bacteriophage genomes and plasmids. Some of the advances in the characterization of the type II-A CRISPR-Cas system of Streptococcus thermophilus and Streptococcus pyogenes led to the development of the CRISPR-Cas9 genome-editing technology. We mostly discuss the 3 stages of the CRISPR-Cas system in S. thermophilus, namely the adaptation stage, which is unique to this resistance mechanism; the CRISPR RNA biogenesis; and the DNA-cutting activity in the interference stage to protect bacteria against phages. Finally, we look into applications of CRISPR-Cas in microbiology, including overcoming limitations in genome editing.
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