The Hna (Helicase-nuclease Abi) phage defence system consists of a single protein and provides defence through abortive infection. We show that Hna's abortive infection response can be recreated in a...

The primary physiological role of toxin/antitoxin (TA) systems is phage defense; they are also used to stabilize mobile genetic elements. In the initial publication in 1996, plasmid-encoded Hok/Sok, a type I TA system (protein toxin, RNA antitoxin that inhibits toxin mRNA), was shown to inhibit T4 phage infection in Escherichia coli by reducing its efficiency of plating and burst size and by increasing the time for mature phage to form (latent period). This publication also identified that the mechanism of Hok/Sok inhibiting T4 was host transcription shutoff, arguably the most-general phage inhibition system since most phages impair host transcription. However, recently, the role of Hok/Sok in phage inhibition has been challenged. Therefore, here we investigated the role of four E. coli chromosomally-expressed, hok+/sok+ loci and the one orphan hok+ locus and found that the Hok proteins inhibit the infection of E. coli by BASEL phage 48, a Vequintavirus with myovirus morphology. Of the five Hok proteins, the greatest phage inhibition was by HokB, and infection by BASEL phages 34 and 39 were also inhibited by HokB. We also find BASEL phage 48 requires the WecB-generated receptor NGR for infection. Therefore, chromosomally-derived orphan Hok proteins, produced at physiological levels, are relevant for phage inhibition. ### Competing Interest Statement The authors have declared no competing interest. U.S. National Science Foundation, https://ror.org/021nxhr62, 2515448

Bacteria evolved a variety of phage defence strategies to combat the constant onslaught of viral threats. DarTG toxin-antitoxin systems provide phage defence by ADP-ribosylation of bases in single-stranded DNA which interferes with viral replication and aborts phage infection. Here, we describe DarHTG, a system widespread among bacteria, that combines DarTG with a non-processive superfamily I helicase functioning as co-toxin for DarT and thereby enabling the ADP-ribosylation of double-stranded DNA. We identified two such DarHTG subclasses which catalyse the ADP-ribosylation of adenosine and guanosine bases, respectively, and reverse these modifications with structurally unique ARH superfamily antitoxins. Thus, DarHTG antitoxins expand the known macromolecular target spectrum of the ARH enzyme class to nucleic acids. These DarHTG systems confer resistance to a broad range of bacteriophages and can be triggered by the highly charged tails of viral single-stranded DNA-binding proteins, which occlude the active site of the ARH antitoxin. ### Competing Interest Statement The authors have declared no competing interest. Lise Meitner Fellowship by Max Planck Society

WASHINGTON — Nearly 7 years’ worth of data from the national bacteriophage therapy program showed that phage therapy is well tolerated and effective, leading researchers to suggest moving from single-...

HIDEN-SEQ (hidden Acr-enabled transposon-insertion sequencing) is a transposon-insertion sequencing method for phages that systematically links their genes to selectable phenotypes.

Screening millions of CRISPR spacers across globally distributed metagenomes reveals unexpected dynamics of phage–host interactions, including many cases where phage genomes seem to repeatedly enter n...

PhD Project - Molecular recognition of biofilm polysaccharides by phage enzymes at University of York, listed on FindAPhD.com

PhD Project - Sex-Specific Phage Therapy for Conflict Wound Healing at University of Southampton, listed on FindAPhD.com

Nature Microbiology, Published online: 29 October 2026; doi:10.1038/s41564-026-02480-7Screening millions of CRISPR spacers across globally distributed metagenomes reveals unexpected dynamics of phage–host interactions, including many cases where phage genomes seem to repeatedly enter non-host cells.

In this Review, the authors summarize structural, biochemical and genetic insights into bacterial immunity, focusing on steps that link infection sensing to activation and effector function.

Giant sulfur-oxidizing bacteria of the family Beggiatoaceae and their symbiotic relatives (Candidatus Epulonipiscium and related taxa) represent some of the largest and most morphologically conspicuou...

Lomeli-Ortega et al. review how peptide-mediated arbitrium signaling enables communication both within and between bacteriophage populations, highlighting how viral crosstalk may influence phage competition, cooperation, and microbial community dynamics while creating opportunities for phage-based technologies.

Synergistic peptide-antibiotic-phage cocktails eradicate multidrug-resistant Serratia marcescens biofilms.