Tatiana Dimitriu

Trade-offs between phage resistance and conjugative ability shape the ecological and evolutionary response of a multidrug resistance plasmid to plasmid-dependent phage Phage therapy is a promising alternative to antibiotics to treat multidrug resistant infections. Plasmid dependent phages (PDPs) are particularly attractive as therapeutics because they can both kill ...

New pre-print www.biorxiv.org/content/10.1...
Plasmid-dependent phage (PDPs) are ubiquitous, but the selective pressures that they impose on plasmids are not well understood. Project led by Daniel Cazares in collaboration with @brockhurstlab.bsky.social!
#phagesky#microsky

Pre- and postantibiotic epoch: The historical spread of antimicrobial resistance Plasmids are now the primary vectors of antimicrobial resistance, but our understanding of how human industrialisation of antibiotics influenced their evolution is limited by a paucity of data predati...

Imagine we could travel back in time ⏪⌛️to explore the world of bacterial pathogens before humans discovered and industrialised antibiotics

We just did that to study the history of #AMR spread @science.org
doi.org/10.1126/scie...

If you like time travel & biology, this 🧵is for you👇

So a small update on French politics for my English speaking followers the guy who had been charged with forming a government and came up with the same government than the previous government has quit this morning following the announcement of his government and is now in charge of forming a new one

Published in Current Biology! P. aeruginosa can use its filamentous phage to inhibit competitors but high phage production is susceptible to cheater miniphage invasion. Subsequent phage tragedy of the commons can lower bacteria and phage fitness. Link: authors.elsevier.com/c/1lt5I3QW8S...

🚂 Sauvons les trains de nuit Paris-Berlin et Paris-Vienne Signez la pétition maintenant !

🚂 😴 A peine lancés et déjà supprimés ? Sauvons les trains de nuit Paris-Berlin et Paris-Vienne, un voyage bas-carbone largement plébiscité par ses utilisateurs et utilisatrices.

Pétition à signer ici ⤵️
agir.greenvoice.fr/petitions/sa...

Now peer-reviewed, improved and published in @microbiologysociety.org Microbiology - thanks to editor and reviewers!

www.microbiologyresearch.org/content/jour...

New ERC funded computational postdoc position in my lab! We are looking for someone who will study the genomics of bacterial evolution using samples from experimental evolution and clinical trials. Lots of opportunities for interesting and fun collaboration!
my.corehr.com/pls/uoxrecru...

Delighted to see our paper studying the evolution of plasmids over the last 100 years, now out! Years of work by Adrian Cazares, also Nick Thomson @sangerinstitute.bsky.social - this version much improved over the preprint. Final version should be open access, apols.
Thread 1/n

Exclusion systems preserve host cell homeostasis and fitness, ensuring successful dissemination of conjugative plasmids and associated resistance genes Abstract. Plasmid conjugation is a major driver of antibiotic resistance dissemination in bacteria. In addition to genes required for transfer and maintena

Exclusion systems, far from slowing down plasmid spread, are in fact essential to preserve host cell viability and thereby ensure the successful dissemination of conjugative plasmids and antibiotic resistance genes.

@nfrk92.bsky.social
@narjournal.bsky.social

academic.oup.com/nar/article/...

A One Health study of Klebsiella pneumoniae species complex plasmids shows a highly diverse and ecologically adaptable plasmidome Plasmids play a pivotal role in the horizontal gene transfer of antimicrobial resistance (AMR) and virulence determinants among bacteria. Members of the Klebsiella pneumoniae species complex (KpSC) ca...

Super paper from the mighty Mia Winkler, @genomarit.bsky.social and Iren Lohr.
"We have previously shown that there were relatively few strain-sharing events across ecological niches...plasmid-sharing is considerably more common across niches than strain-sharing. "
www.biorxiv.org/content/10.1...

Phenotypic heterogeneity of capsule production across opportunistic pathogens | mBio The polysaccharidic capsule is present in ~50% of species across the bacterial phylogeny, including all ESKAPE microorganisms, the six most significant multidrug-resistant (MDR) nosocomial pathogens. It is also an important virulence factor and a major ...

Delighted to share our recently published work!
Ever wondered how Klebsiella (and others) deals with capsule production’s costs ?
The paper: journals.asm.org/doi/10.1128/...
Thread👇

Photo of the bottom of a mug covered in fungal contamination, in blue-gray tones with some blue and white more distinct outgrowths

only a microbiologist can be happy she left home in a rush three weeks ago and did not empty her tea mug @contamclub.bsky.social

Type VI secretion system activity at lethal antibiotic concentrations leads to overestimation of weapon potency Competition assays are a mainstay of modern microbiology, offering a simple and cost-effective means to quantify microbe–microbe interactions in vitro. Here, we demonstrate a key weakness of this meth...

Does your lab perform killing assays?
TL;DR: we’ve identified a problem that can bias the outcome of killing assays, making antagonism look stronger than it really is.
Adding a simple extra step can mitigate this bias!

Out now at #MicrobioJ www.microbiologyresearch.org/content/jour...

1/n

Genomic resistance in historical clinical isolates increased in frequency and mobility after the age of antibiotics Antibiotic resistance is frequently observed shortly after the clinical introduction of an antibiotic. Whether and how frequently that resistance occurred before the introduction is harder to determin...

What was antibiotic resistance like before we ever used antibiotics? How did we change what antibiotic resistance genes looked like over 100 years?

Our paper looking at resistance genes from a century of NCTC historical isolates now out in mGen:
www.microbiologyresearch.org/content/jour...

Various views of Provence countryside with dark green and yellow-green vegetation, blue sky and white clouds

This is my happy place and I'm not sure I want to leave ever

Plasmids promote antimicrobial resistance through Insertion Sequence-mediated gene inactivation Antimicrobial Resistance (AMR) is a major threat to public health. Plasmids are mobile genetic elements that can rapidly spread across bacterial populations, promoting the dissemination of AMR genes i...

New paper out! 🔈🔈📣📣

Plasmids promote antimicrobial resistance through Insertion Sequence-mediated gene inactivation.

Combining experimental and computational approaches, we unveil how two of the most prevalent bacterial MGE accelerate the evolution of AMR. 🧵👇🏻

www.biorxiv.org/content/10.1...

Plasmid prevalence is independent of antibiotic resistance in environmental Enterobacteriaceae The rapid rise of antibiotic-resistant pathogens poses a critical threat to the treatment of infectious diseases. While the spread of antibiotic resistance genes (ARGs) via plasmid conjugation has bee...

If you ever find yourself needing evidence for ‘Plasmids are just as common in microbes without resistance genes,’ we’ve got you covered! Check our new paper, out today:

www.microbiologyresearch.org/content/jour...

Research position in Microbial Pharmacology and Population Biology (282139) | UiT The Arctic University of Norway Job title: Research position in Microbial Pharmacology and Population Biology (282139), Employer: UiT The Arctic University of Norway, Deadline: Wednesday, August 27, 2025

Feels surreal to say but: I'm hiring! If you are or know anyone interested in looking at the evolution of phage resistance using A. baumannii and natural transformation, then this might be for you
www.jobbnorge.no/en/available...

(the soup thing sounds very English to me as I grew up with the Astérix joke of English food being boiled water seasoned with some more water)

I love this book, it is for a large part about an AI which becomes conscious because it was asked to narrate a story and is struggling with it. But the “building made of soups” bit made me laugh out loud and I’m not sure if it’s about language in general or a specific go at English?

A most fuzzy mathematics. Possibly utterly useless. […] Their languages lie to them, systemically, and in their very designs. A liar species. What a thing, really. What an evolutionary dead end. “
Kim Stanley Robinson, Aurora. 2/2

“We sense this, we aggregate that, we compress information to some new output, in the form of a sentence in a human language, a language called English. A language both very structured and very amorphous, as if it were a building made of soups. 1/2

Want to name a real virus? I have recently discovered 9 new phages which now need names! To enter, you simply need to donate to the Cystic Fibrosis Trust on my JustGiving page (£2 = 1 entry) and share your email with me on donation (see link info). Please share 💚 www.justgiving.com/page/meaghan-c-1

… and on the other extreme, papers describing in great detail a chemical or experimental condition that reduces transfer by like 20%, and concluding that we just have to use this and we will solve AMR.

It is funny reading papers from labs with different interests and approaches, which consider variation in conjugation rates in opposite ways: on one side (more molecular genetics), dismissing anything less than 10-fold or 100-fold as ‘not really involved in transfer’

😍il faut qu'on s'organise 🏴󠁧󠁢󠁳󠁣󠁴󠁿

Plasmids link antibiotic resistance genes and phage defense systems in E. coli Phage therapy has been proposed as an alternative to antibiotics to treat resistant infections. However, we have a limited understanding of how antibiotic resistance genes (ARGs) associate with bacter...

New pre-print from my lab!
Plasmids link antibiotic resistance and phage defense.

E.coli plasmids are hotspots for both antibiotic resistance and phage defense. Phage therapy has the potential to accidentally select for antibiotic resistance!!!
#microsky#AMR#phage

www.biorxiv.org/content/10.1....

Kiwa is a membrane-embedded defense supercomplex activated at phage attachment sites Zhang, Todeschini, and Wu et al. show that the bacterial defense system Kiwa senses phage attachment at the membrane and assembles a transmembrane complex that halts infection by blocking phage DNA re...

Thrilled to see our Kiwa story out today! A membrane-associated supercomplex that senses infection and blocks replication and transcription.

www.cell.com/cell/fulltex...

Huge congratulations to Yi and Zhiying for bringing it home, to Thomas for starting us off, and to all the collaborators.

🦠🧍‍♀️From bacterial to human immunity.

We report in @science.org the discovery of a human homolog of SIR2 antiphage proteins that participates in the TLR pathway of animal innate immunity.
Co-led wt @enzopoirier.bsky.social by D. Bonhomme and @hugovaysset.bsky.social

www.science.org/doi/10.1126/...

graphical abstract of the article the extended mobility of plasmids

Here's our new broad review on the extended mobility of plasmids, about all mechanisms driving and limiting their transfer. From conjugation to conduction, phage-plasmids to hitchers, molecular to evolutionary dynamics, ecology to biotech. The state of affairs. 1/9 academic.oup.com/nar/article/...