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Now out in AEM @asm.org! 🎉🧪 *High school student-isolated mutants 👉🏻 novel genetic causes of biofilm-associated adaptations *We learn how diversity arises quickly and is maintained *EvolvingSTEM enables scalable research in classrooms & promotes scientific literacy journals.asm.org/eprint/FBU9M...

Bacterial biofilms dominate microbial life; however, their evolutionary genetics remain incompletely understood. Extensive replication of biofilm selection experiments by secondary school students can...

Very proud of this work and all the efforts from my team and collaborators on this! You can now use DGRs for in vivo targeted hypermutagenesis in E. coli. We also included some early proof of concept in Yeast thanks to @seth-shipman.bsky.social !

Here’s the latest preprint from my work on evolved resistance to Type VI Secretion system (T6SS) weaponry, funded by a @wellcometrust.bsky.social Sir Henry Wellcome Fellowship. So happy to see this out! www.biorxiv.org/content/10.6...

Sharing the most significant work from my group, led by the @evolvingstem.bsky.social team. Come for the discoveries of how Pseudomonas adapts in biofilms, stay for the story of how they were discovered by thousands of young scientists in grades 9-12. 🧪🧫🧬🧵 www.biorxiv.org/content/10.1...

We established a research-education partnership known as EvolvingSTEM that provides secondary school students the opportunity to conduct authentic research experiments centered on microbial evolution....

New paper out! 🔈 Genomic Characterization of the RyC collection: 50 Multidrug Resistant Clinical Isolates of Escherichia coli and Klebsiella spp. 50 MDR gut isolates, 2 sequencing platforms, 4 “omes,” and 1 mission: provide a resource to decode AMR and MGE dynamics www.biorxiv.org/content/10.6...

🚨 New preprint from the lab! 🚨 We show that multireplicon plasmids are true AMR "jack-of-all-trades": Widespread, highly mobile, broad host-range, and packed with resistance genes. Far from random, they form co-evolving associations driven & 𝘮𝘢𝘪𝘯𝘵𝘢𝘪𝘯𝘦𝘥 by IS elements. See Nacho's thread below!👇👇

Ayer, @sanmillan.bsky.social, investigador en el #CNB_CSIC, participó en #DesayunoDeINNOVACIÓN de @innovaspain.bsky.social en colaboración con Fundación Pfizer. El evento abordó claves para reforzar la transferencia de conocimiento en el sector salud y reforzar el papel de España como referente.

Plasmids are DNA molecules that replicate independently of the bacterial chromosome and are typically associated with the spread of antimicrobial resistance (AMR) and virulence determinants, among other relevant traits. Fusion events between plasmids generate larger, complex backbones that carry two or more replication systems, known as multireplicon plasmids. Despite decades of study, we are still far from understanding how multireplicon plasmids arise, persist, and shape the evolution of AMR. Here, we analyzed 24,000 non-redundant plasmids across bacterial genera and found that more than 30% of them encoded multiple replicons. Compared to single-replicon plasmids, multireplicon plasmids were larger, were enriched in genes encoding antimicrobial, metal, and biocide resistance as well as virulence factors, and showed higher mobility and a broader host range. We also found that multireplicon assembly is not random. Some replicon pairs repeatedly merge into stable multireplicon plasmids, while other pairs rarely fuse even when they commonly coexist intracellularly. We also show that replicon pairs tend to be localized either in close proximity to one another or on opposite poles of the plasmid. We further highlight that multireplicon plasmids can be broadly classified into two groups: long-term coevolving replicon pairs and transient associations that lack a shared evolutionary history. Finally, we reveal the molecular mechanisms underlying multireplicon formation and highlight the role of insertion sequences in their formation and maintenance. Together, our work sheds light on the abundance, gene content, evolutionary patterns, and formation dynamics of multireplicon plasmids and pinpoints their relevance to bacterial evolution and human health. ### Competing Interest Statement The authors have declared no competing interest. Instituto de Salud Carlos III, https://ror.org/00ca2c886, PI23/01945, PFIS - FI22/00265, Miguel Servet - CP22/00164 European Research Council, https://ror.org/0472cxd90, HorizonGT, 101077809 Fundación Ramón Areces, "Ayudas Fundación Ramón Areces para la realización de Tesis Doctorales en Ciencias de la Vida y de la Materia 2025" Coordenação de Aperfeicoamento de Pessoal de Nível Superior, https://ror.org/00x0ma614, 88881.128025/2025-01

En #AGolpeDeBit #RTVE, @sanmillan.bsky.social investigador del #CNB @csic.es habla de este estudio liderado junto a Alfonso Santos López @uam.es y en colaboración con Ayari Fuentes #UNAM_MX centrado en el plásmido pOXA-48 de gran interés clínico 📻 ¡No te lo pierdas! www.rtve.es/play/audios/...

🔈Paper out! We turned the most fascinating phage host-switch mechanism, diversity-generating retroelements, into a programmable mutagenesis tool, DGRec. You can perform targeted hypermutation of any 50-200bp sequence directly in vivo in E. coli www.nature.com/articles/s41...

Diversity-generating retroelements are engineered for directed evolution in E.coli.

We are pleased to share our last article rdcu.be/fabhM. It offers the most comprehensive analysis so far of Ab+non-Ab resistance genes in human gut microbiome, using an Indigenous population (low industrialization, chronic Hg exposure from gold mining) 6/6👇

New preprint alert!!! 🚀🤓 We are very happy to finally share this with the world — the result of seven years of work and a new tool to study integrons and discover new functions encoded in these bacterial platforms. If you want to know more, here is a thread 🧵 www.biorxiv.org/content/10.6...

Jerónimo Rodríguez-Beltrán

My main postdoc paper is now out in @natureportfolio.nature.com npj Antimicrobials and Resistance! www.nature.com/articles/s44.... Using flow cytometry, we show that the nucleoside analogues azidothymidine, didanosine, stavudine, and trifluridine reduced transfer of AMR plasmids pCT and pKpQIL (1/3)

Centro Nacional de Biotecnología (CNB)

npj Antimicrobials and Resistance - Mechanistic insights into plasmid transfer inhibition in Enterobacterales by nucleoside analogues

Filipa Trigo da Roza

What if multireplicon plasmids are not an oddity, but an evolutionary strategy? We found that they are common, more mobile, broader-host-range, and enriched in AMR. Even more interesting: their assembly doesn’t look random. 👀 Paper preprint: www.biorxiv.org/content/10.6... Thread below!🧵👇

Ponemos el foco en un estudio que identifica un nuevo mecanismo por el que los plásmidos pueden acelerar la aparición de resistencia a los antibióticos

Ignacio (Nacho) de Quinto