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Alicia Calvo-Villamañán

@aliciapcv.bsky.social

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Alicia Calvo-Villamañán @aliciapcv.bsky.social · Aug 20

This work is finally published! 🥳🧬
Plasmids are associated with very variable fitness costs in their different bacterial hosts. But, what is the contribution of each of the plasmid-genes in these host-specific effects? Study led by
@jorgesastred.bsky.social, @sanmillan.bsky.social and myself! 1/14

Dissecting pOXA-48 fitness effects in clinical Enterobacterales using plasmid-wide CRISPRi screens

Nature Communications - This study investigates the effects of the carbapenem resistance plasmid pOXA-48 in clinical enterobacteria. Using CRISPRi screens, the authors revealed that the...

rdcu.be

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Reposted by Alicia Calvo-Villamañán

Doudna Lab @doudna-lab.bsky.social · 7d

New paper online at @nature.com from co-leads @erinedoherty.bsky.social + @benadler.bsky.social !

Erin Doherty @erinedoherty.bsky.social · 7d

Now online at @nature.com we show how the Panoptes defense system protects against viruses that attempt immune evasion - and expands our understanding of the role of oligonucleotides in immunity.

Check out this work co-led with @benadler.bsky.social here:

www.nature.com/articles/s41...

A miniature CRISPR–Cas10 enzyme confers immunity by inhibitory signalling - Nature

Panoptes, an anti-phage defence system against virus-mediated immune suppression, is revealed.

www.nature.com

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Reposted by Alicia Calvo-Villamañán

Institut Pasteur Education @pasteuredu.bsky.social · 8d

🔬PPU 2025 Call for Candidates - Discover the PhD projects

Today's featured projects: 4 Cell Biology & Infection projects and 2 Parasites & Insect Vectors projects

🗓 Applications deadline: October 20, 2025
📍Program starts: October 2026

Discover all projects & apply now: bit.ly/4nlPz8x

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Alicia Calvo-Villamañán @aliciapcv.bsky.social · Sep 4

Congratulations François!! So well deserved 🥳🥳

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Reposted by Alicia Calvo-Villamañán

Eduardo Rocha @epcrocha.bsky.social · Aug 27

Very happy to see this one out: doi.org/10.1093/molbev/msaf192
Here, we assessed the contribution of natural transformation to the acquisition of novel genes. See preprint thread. @molbioevol.bsky.social #microsky #evobio

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Reposted by Alicia Calvo-Villamañán

Centro Nacional de Biotecnología (CNB) @cnb-csic.bsky.social · Aug 27

El grupo de Álvaro San Millán revela el coste de mantener la resistencia en enterobacterias

El trabajo traza un mapa funcional del plásmido pOXA-48, con potencial para guiar nuevas terapias contra resistencias

bit.ly/4p0fCmY

@sanmillan.bsky.social @aliciapcv.bsky.social @jorgesastred.bsky.social

Identifican el coste fisiológico de mantener la resistencia microbiana en enterobacterias - CNB

bit.ly

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Reposted by Alicia Calvo-Villamañán

Jana Huisman @jhuisman.bsky.social · Aug 25

Have you ever wondered what increasing environmental stress will do to microbial communities?

In our new preprint, @martinadalbello.bsky.social, Jeff Gore and I studied the impact of salinity on microbial community composition and function. 🧵 (1/5)
www.biorxiv.org/content/10.1...

Microbial communities demonstrate robustness in stressful environments due to predictable composition shifts

Environmental stress reduces species growth rates, but its impact on the function of microbial communities is less clear. Here, we experimentally demonstrate that increasing salinity stress shifts com...

www.biorxiv.org

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Reposted by Alicia Calvo-Villamañán

Nature Microbiology @natmicrobiol.nature.com · Aug 22

#NatMicroPicks

AI Designs Next-Gen Antibiotics! 💊🤖

Generative deep learning and genetic algorithms created structurally novel antibiotics that effectively target drug-resistant bacteria, offering a powerful new tool to combat drug resistance.

#MicroSky #AMR

www.cell.com/cell/abstrac...

A generative deep learning approach to de novo antibiotic design

A generative AI platform is developed for de novo antibiotic design, yielding lead compounds with selective antibacterial activity, distinct mechanisms of action, and in vivo efficacy against multidru...

www.cell.com

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Alicia Calvo-Villamañán @aliciapcv.bsky.social · Aug 22

Thank you Jorge! As always, it was a pleasure working with you 🤩

Reposted by Alicia Calvo-Villamañán

Sarah Bigot @sbigot.bsky.social · Aug 20

Our paper “Genetic determinants of pOXA-48 plasmid maintenance and propagation in Escherichia coli” is now online in @natcomms.nature.com ✨
👉 www.nature.com/articles/s41...
@cnrs-rhoneauvergne.bsky.social @mmsb-lyon.bsky.social

Genetic determinants of pOXA-48 plasmid maintenance and propagation in Escherichia coli - Nature Communications

pOXA-48 plasmids have emerged as key vectors of carbapenem resistance within Enterobacteriaceae. In this study, the authors use a transposon sequencing (Tn-seq) approach to identify genetic determinan...

www.nature.com

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Reposted by Alicia Calvo-Villamañán

Jerónimo Rodríguez-Beltrán @jerorb.bsky.social · Jul 2

🚨🚨New paper out in @natcomms.nature.com!!

Come for the first large-scale analysis of plasmid copy number across species,
stay for one of the most intriguing results of my lab: universal scaling laws in plasmid biology! 📈🧬

👉 www.nature.com/articles/s41...

Universal rules govern plasmid copy number - Nature Communications

Plasmids exhibit a broad range of sizes and copies per cell, and these two parameters appear to be negatively correlated. Here, Ramiro-Martínez et al. analyse the copy number of thousands of diverse b...

www.nature.com

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Reposted by Alicia Calvo-Villamañán

Didier Mazel @amazeld.bsky.social · Aug 20

For those who love bacterial replicons, The ultimate review, from our lab, signed by the master of their evolution.
‪@val-meve.bsky.social‬ www.sciencedirect.com/science/arti...

Taming wild replicons: evolution and domestication of large extrachromosomal replicons

Bacterial genomes often contain extrachromosomal replicons (ERs), ranging from small, mobile plasmids to large, stably inherited elements, such as meg…

www.sciencedirect.com

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Alicia Calvo-Villamañán @aliciapcv.bsky.social · Aug 21

Thank you very much Rita 🎉

Alicia Calvo-Villamañán @aliciapcv.bsky.social · Aug 20

Thank you very much David 🥳 A congrats from my PhD supervisor will forever be worth twice the happiness points! 🥲

Alicia Calvo-Villamañán @aliciapcv.bsky.social · Aug 20

Muchas gracias Ana Elena!!! Hay que celebrarlo! 🥳

Alicia Calvo-Villamañán @aliciapcv.bsky.social · Aug 20

Muchas gracias Olaya!!!

Alicia Calvo-Villamañán @aliciapcv.bsky.social · Aug 20

Thank you very much Zamin!

Alicia Calvo-Villamañán @aliciapcv.bsky.social · Aug 20

Muito obrigada Filipa! 🥳🥳

Alicia Calvo-Villamañán @aliciapcv.bsky.social · Aug 20

Thank you very much Dave! I am glad you enjoyed it!

Alicia Calvo-Villamañán @aliciapcv.bsky.social · Aug 20

It was really fun to work on this project! We hope you enjoy reading it as much as we did working on it 🙂

a man and a woman are jumping in the air in a hallway with their hands in the air .

ALT: a man and a woman are jumping in the air in a hallway with their hands in the air .

media.tenor.com

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Alicia Calvo-Villamañán @aliciapcv.bsky.social · Aug 20

We would like to end by thanking @natcomms.nature.com and the reviewers for their comments that made our original manuscript stronger and more useful to the community. And @cnb-csic.bsky.social for their support. We would also like to thank our colleagues on whose work we build our own!

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Alicia Calvo-Villamañán @aliciapcv.bsky.social · Aug 20

Our results also highlight the usefulness of using high-throughput techniques to explore previously unknown biological phenomena at a genetic level, and the need to perform said studies in realistic set-ups such as clinical strains. 14/14

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Alicia Calvo-Villamañán @aliciapcv.bsky.social · Aug 20

All in all, our study highlights the role of different plasmid-encoded genes in the biology of pOXA-48 and opens new doors to explore alternative ways to fight AMR in enterobacteria. 13/14

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Alicia Calvo-Villamañán @aliciapcv.bsky.social · Aug 20

This opens a gateway to explore new ways to exploit these physiological changes as potential new antimicrobial strategies. 12/14

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Alicia Calvo-Villamañán @aliciapcv.bsky.social · Aug 20

Expressing BlaOXA-48 leads to changes in the cell envelope, thus leading to a decrease in the fitness of the cell. This means that carrying plasmids such as pOXA-48 can have downstream repercussions, such as said fitness costs and even collateral sensitivity to other antibiotics. 11/14

Collateral sensitivity associated with antibiotic resistance plasmids

Acquisition of antibiotic resistance plasmids induces collateral sensitivity to clinically relevant antibiotics in Escherichia coli, paving the way for targeted 'anti-plasmid' therapies able to prefer...

elifesciences.org

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Alicia Calvo-Villamañán @aliciapcv.bsky.social · Aug 20

In fact, deleting blaOXA-48 from pOXA-48 strongly decreases the cost associated with the plasmid. 10/14

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