Plasmids drive bacterial adaptation, but how their diversity arises has remained unclear. Here, they show that in Staphylococcus aureus, mobile genetic elements repeatedly fuse and delete plasmids, re...

Plasmids in bacteria and extrachromosomal DNA in cancer both generate copy-number variation, alter gene expression and promote rapid adaptation. In this Perspective, Shaw and Henssen explore their sha...

Using Hi-C metagenomics, this study maps how plasmids associate with bacterial hosts across wastewater treatment. They find that plasmid host range narrows from influent to effluent, and a few bacteri...

Abstract. Toxin-antitoxin systems (TAs) are widespread in bacterial genomes. Yet, their integration, persistence, and impact in chromosome dynamics remain

Viruses are ubiquitous mobile genetic elements that are obligate symbionts of cellular life forms and replicate exclusively within host cells. The ...

Project Code IIAR27Ex van Houte Project Type Wet lab Research Theme Infection, Immunity, and Antimicrobial Resistance Project Summary Download Summary Antimicrobial resistance (AMR) poses a major thre...

Project Code IIAR27Ba Matlock Project Type Wet lab Research Theme Infection, Immunity, and Antimicrobial Resistance Project Summary Download Summary Plasmids are important drivers of antimicrobial res...

Abstract. Outbreak sequencing provides insight into the origin and evolutionary processes acting on emerging pathogens. Sequencing a historic multihost out

Antibiotic heteroresistance, the presence of a rare resistant subpopulation within an otherwise susceptible bacterial population, poses a significant clinical challenge. Understanding its genetic mechanisms is critical for early detection and treatment efficacy. Here, we investigate the contribution of small plasmids to heteroresistance using a clinical bloodstream Escherichia coli isolate carrying a 12 kb ColE1-type plasmid (p12). We show that this plasmid drives transient β-lactam heteroresistance through massive increases in plasmid copy number. Two distinct genetic mechanisms drive this amplification: mutations in the plasmid RNAI/RNAII that deregulate replication control, and a chromosomal recD mutation that induces multimerization and a shift toward rolling-circle replication. Notably, this recD-mediated amplification is restricted to small ColE1 and F- plasmids. This study highlights the crucial role of small plasmids in resistance evolution, demonstrating that they can cause this phenotype via alternative genetic pathways, without the involvement of traditional large resistance plasmids. ### Competing Interest Statement The authors have declared no competing interest. Swedish Research Council, https://ror.org/03zttf063, 2024-03665, 2024-06136, 2021-02091 NIH Common Fund, https://ror.org/001d55x84, 1U19AI158080-01

Abstract. To successfully transfer, conjugative plasmids must overcome a recipient cell’s defence mechanisms. The leading region of many plasmids—the first

Abstract. To successfully transfer, conjugative plasmids must overcome a recipient cell’s defence mechanisms. The leading region of many plasmids—the first

The bacteriophage ΦX174 was the first genome to be sequenced and the first to be chemically synthesised. Here we present a complete map of the consequences of changing every nucleotide in the ΦX174 ge...

In a recent Cell paper, Maurais et al. show that genomic instability drives human cells to transfer fragmented chromosomes to neighbors via tunneling nanotubes (TNTs), with heritable functional consequences, raising fundamental questions about intercellular communication, genome surveillance, and cancer evolution.

CRISPR–Cas systems transcriptionally tune diverse innate defences using CRISPR RNA-like guides to balance antiviral protection with fitness, and hyperactivate these defences when compromised, establis...

Plasmids are extrachromosomal mobile genetic elements that can facilitate rapid bacterial adaptation by transferring genes between individuals. Whilst plasmids are known to exist in diverse habitats a...