Nature Reviews Microbiology, Published online: 02 October 2026; doi:10.1038/s41579-026-01376-xBacteria deploy diverse immune systems to counter phage infection, yet how these systems sense invasion remains incompletely understood. This Review categorizes phage-derived triggers and outlines emerging principles that govern immune recognition of phage infection.

Cyclic oligonucleotide–based antiphage signaling systems (CBASS) are bacterial immune pathways evolutionarily related to cGAS-STING (cyclic GMP-AMP synthase–stimulator of interferon genes) in humans. ...

Using affinity purification-mass spectrometry, these authors identified the Healer system, a phage two-protein effector that repairs CRISPR-mediated DNA breaks via homologous recombination.

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Cultured phage collections provide essential access to viral biology, but they capture only a small and biased fraction of natural phage diversity. Key barriers to diverse phage isolation are likely t...

Ancient viral warfare could be at the root of modern class 1 CRISPR bacterial defense systems

CRISPR-Cas provides RNA-mediated adaptive immunity, but how its first RNA-guided effector arose is unclear. In this study, we report the discovery of Viral Interference Programmable Repeat (VIPR) syst...

The BASEL collection of phages that infect E. coli has been a valuable resource, but is limited by the peculiarities of the host strain used. This study uses a modified host to expand the collection…

Gabija acts early during phage infection, preventing phage genome circularization and replication. Phage DNA end-binding proteins prevent RecBCD loading onto linear DNA, and the absence of RecBCD lice...

Many bacterial anti-phage defence systems are encoded by mobile genetic elements, yet much of this antiviral repertoire remains undiscovered. Antimicrobial-resistance plasmids are well known for disse...

Recent discoveries on bacterial immunity have revealed that several protein domains involved in anti-phage defense are conserved in eukaryotes, such as SIRim, TIR, PNP and gasdermin. Bacterial immune ...

Here the authors determine the structure and mechanism of the QatABCD anti-phage defense system, showing how the QueCfamily protein QatC recognizes QatB to enable bacterial antiviral immunity and highlighting a conserved role for QueC-family proteins in protein modification.

Viruses are intracellular parasites that reprogram the host proteome to promote replication and evade immune recognition. We applied a virome-wide library of ~10,000 open reading frames to discover vi...

The T7 bacteriophage deactivates bacterial defence systems through T7K phosphorylation of nearly all host and phage proteins during infection.

The T7 bacteriophage deactivates bacterial defence systems through T7K phosphorylation of nearly all host and phage proteins during infection.

Diverse E. coli phage genomes have hypermutable DNA regions that promote reversible frameshift mutations through DNA polymerase slippage, generating population heterogeneity that enables host exploita...

Bacterial diadenylate cyclase (DAC) enzymes synthesize the nucleotide signal 3′3′ cyclic di-AMP (3′3′-c-di-AMP) to control osmoregulation, cell-wall homeostasis, and DNA-damage responses. Here we disc...

Many bacterial immune defenses transmit recognition of phage infection via the generation of diverse cyclic nucleotide second messengers. Phage have evolved to subvert this kind of immunity by sequest...

The Review describes shared ancient, conserved mechanisms between human antiviral immunity and bacterial anti-phage systems, outlining universal principles of pathogen sensing, signalling and effector...

Quantitative microscopy of microorganisms increasingly produces large, multidimensional datasets, yet their analysis often depends on fragmented workflows spanning file conversion, segmentation, quali...

DNA glycosylases, typically used for DNA repair, can also protect bacteria against phages that would otherwise evade host immunity by incorporating modified bases into their genomes.