Strengthening phage resistance of Streptococcus thermophilus by leveraging complementary defense systems.

ABSTRACT: CRISPR-Cas and restriction-modification systems represent the core defense arsenal in Streptococcus thermophilus, but their effectiveness is compromised by phages encoding anti-CRISPR proteins (ACRs) and other counter-defense strategies. Here, we explore the defensome of 263 S. thermophilus strains to uncover other anti-phage systems. The defense landscape of S. thermophilus is enriched by 21 accessory defense systems, 13 of which have never been investigated in this species. Experimental validation of 17 systems with 14 phages reveals a range of anti-phage activities, highlighting both broad and narrow specificities across the five viral genera infecting S. thermophilus. Synergies are observed when combining CRISPR immunity with accessory systems. We also assess the fitness cost associate

SUBMITTER: Leprince A 

PROVIDER: S-EPMC12322248 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature