Frédérique Le Roux
@fredoleroux.bsky.social
Professeure/chaire d'excellence du Canada
Université de Montréal
Département de microbiologie, infectiologie et immunologie
What do I like? Wild things 😜 yet phages are my favorite!
Université de Montréal
Département de microbiologie, infectiologie et immunologie
What do I like? Wild things 😜 yet phages are my favorite!
Reposted by Frédérique Le Roux
🦠💊 L’Institut @pasteur.fr vient de publier un communiqué de presse sur nos récents travaux, qui décrivent une nouvelle piste pour augmenter l’efficacité des antibiotiques. #Pasteurdon #Recherche #Science #AMR
Merci à toutes celles et ceux qui ont contribué.
📘 English version coming soon!
Merci à toutes celles et ceux qui ont contribué.
📘 English version coming soon!
Une piste prometteuse pour augmenter l’efficacité des antibiotiques
Les aminosides sont des antibiotiques efficaces contre de très nombreuses bactéries telles que Escherichia coli, Pseudomonas aeruginosa ou Staphylococcus aureus. Mais jusqu’à présent, personne ne sava...
www.pasteur.fr
October 31, 2025 at 10:37 AM
🦠💊 L’Institut @pasteur.fr vient de publier un communiqué de presse sur nos récents travaux, qui décrivent une nouvelle piste pour augmenter l’efficacité des antibiotiques. #Pasteurdon #Recherche #Science #AMR
Merci à toutes celles et ceux qui ont contribué.
📘 English version coming soon!
Merci à toutes celles et ceux qui ont contribué.
📘 English version coming soon!
Reposted by Frédérique Le Roux
Many thanks to all those involved, including Jeffrey Liang, who stayed in our lab for several months, our own Charles Bernard and, of course, @fredoleroux.bsky.social and the usual suspects @agencerecherche.bsky.social @erc.europa.eu @cnrsbiologie.bsky.social @pasteur.fr @umontreal.ca etc
October 14, 2025 at 4:08 PM
Many thanks to all those involved, including Jeffrey Liang, who stayed in our lab for several months, our own Charles Bernard and, of course, @fredoleroux.bsky.social and the usual suspects @agencerecherche.bsky.social @erc.europa.eu @cnrsbiologie.bsky.social @pasteur.fr @umontreal.ca etc
Reposted by Frédérique Le Roux
Two intensive sampling periods of oyster-associated vibrio and their phage, 4 years apart, and many surprises. Despite being washed by the Atlantic, wide tides, and vibrio (almost?) disappearing most of the year, we can find the exact same virulent phages 4 years later (down to 0 SNP)! preprint👇
October 14, 2025 at 4:08 PM
Two intensive sampling periods of oyster-associated vibrio and their phage, 4 years apart, and many surprises. Despite being washed by the Atlantic, wide tides, and vibrio (almost?) disappearing most of the year, we can find the exact same virulent phages 4 years later (down to 0 SNP)! preprint👇
Phages evolve fast, or do they?
In oysters, some stay identical for years.
With >1,200 phages & 600 Vibrio genomes, we reveal long-term stability and new mobile elements.
Proud of this collaborative work across our teams (Roscoff-UdeM and @epcrocha.bsky.social www.biorxiv.org/cgi/content/...
In oysters, some stay identical for years.
With >1,200 phages & 600 Vibrio genomes, we reveal long-term stability and new mobile elements.
Proud of this collaborative work across our teams (Roscoff-UdeM and @epcrocha.bsky.social www.biorxiv.org/cgi/content/...
Ecological constraints foster both extreme viral-host lineage stability and mobile element diversity in a marine community
Phages are typically viewed as very rapidly evolving biological entities. Little is known, however, about whether and how phages can establish long-term genetic stability. We addressed this eco-evolut...
www.biorxiv.org
October 12, 2025 at 9:16 PM
Phages evolve fast, or do they?
In oysters, some stay identical for years.
With >1,200 phages & 600 Vibrio genomes, we reveal long-term stability and new mobile elements.
Proud of this collaborative work across our teams (Roscoff-UdeM and @epcrocha.bsky.social www.biorxiv.org/cgi/content/...
In oysters, some stay identical for years.
With >1,200 phages & 600 Vibrio genomes, we reveal long-term stability and new mobile elements.
Proud of this collaborative work across our teams (Roscoff-UdeM and @epcrocha.bsky.social www.biorxiv.org/cgi/content/...
Reposted by Frédérique Le Roux
Thrilled to share our two latest papers with the @tcostalab.bsky.social
lab! In the first, we uncover a new mechanism of satellite transfer: cf-PICIs hijack tails from diverse phages to spread across species.
@imperialcollegeldn.bsky.social
www.cell.com/cell/fulltex...
lab! In the first, we uncover a new mechanism of satellite transfer: cf-PICIs hijack tails from diverse phages to spread across species.
@imperialcollegeldn.bsky.social
www.cell.com/cell/fulltex...
Chimeric infective particles expand species boundaries in phage-inducible chromosomal island mobilization
Capsid-forming PICIs (cf-PICIs) produce their own capsids and exploit phage tails
from unrelated species to transfer their DNA across bacterial hosts. This tail piracy
enables broad dissemination and ...
www.cell.com
September 9, 2025 at 5:05 PM
Thrilled to share our two latest papers with the @tcostalab.bsky.social
lab! In the first, we uncover a new mechanism of satellite transfer: cf-PICIs hijack tails from diverse phages to spread across species.
@imperialcollegeldn.bsky.social
www.cell.com/cell/fulltex...
lab! In the first, we uncover a new mechanism of satellite transfer: cf-PICIs hijack tails from diverse phages to spread across species.
@imperialcollegeldn.bsky.social
www.cell.com/cell/fulltex...
Reposted by Frédérique Le Roux
Chimeric infective particles expand species boundaries in phage-inducible chromosomal island mobilization: Cell www.cell.com/cell/fulltex...
Chimeric infective particles expand species boundaries in phage-inducible chromosomal island mobilization
Capsid-forming PICIs (cf-PICIs) produce their own capsids and exploit phage tails
from unrelated species to transfer their DNA across bacterial hosts. This tail piracy
enables broad dissemination and ...
www.cell.com
September 9, 2025 at 3:27 PM
Chimeric infective particles expand species boundaries in phage-inducible chromosomal island mobilization: Cell www.cell.com/cell/fulltex...
Reposted by Frédérique Le Roux
The ecology and evolution of microbial immune systems: a look on the wild vibrio side
Phil. Trans. R. Soc. B by @fredoleroux.bsky.social
royalsocietypublishing.org/doi/10.1098/...
Phil. Trans. R. Soc. B by @fredoleroux.bsky.social
royalsocietypublishing.org/doi/10.1098/...
The ecology and evolution of microbial immune systems: a look on the wild vibrio side | Philosophical Transactions of the Royal Society B: Biological Sciences
Natural populations of vibrio beyond the well-studied pandemic strains of Vibrio cholerae, provide a powerful model for investigating the eco-evolutionary dynamics of microbial immune systems. Their genetic diversity, ecological versatility, ease of ...
royalsocietypublishing.org
September 5, 2025 at 10:20 AM
The ecology and evolution of microbial immune systems: a look on the wild vibrio side
Phil. Trans. R. Soc. B by @fredoleroux.bsky.social
royalsocietypublishing.org/doi/10.1098/...
Phil. Trans. R. Soc. B by @fredoleroux.bsky.social
royalsocietypublishing.org/doi/10.1098/...
👉 Next stop: Montréal! 🇨🇦 Thrilled to join the Canada Society of Microbiology (CSM) conference, June 17-20. Science, community, and reconnecting with old friends — can’t wait!
June 9, 2025 at 5:30 PM
👉 Next stop: Montréal! 🇨🇦 Thrilled to join the Canada Society of Microbiology (CSM) conference, June 17-20. Science, community, and reconnecting with old friends — can’t wait!
Reposted by Frédérique Le Roux
The study involves our microbiologist @fredoleroux.bsky.social, whom we profiled in late 2023 as a new hire and Canada Excellence in Research Chair: nouvelles.umontreal.ca/en/article/2...
June 9, 2025 at 4:19 PM
The study involves our microbiologist @fredoleroux.bsky.social, whom we profiled in late 2023 as a new hire and Canada Excellence in Research Chair: nouvelles.umontreal.ca/en/article/2...
Reposted by Frédérique Le Roux
Allo Montreal, 11 juin –18H au café La brassée:
"Des sphères aux spirales, des extrémophiles aux probiotiques: plongez dans l’univers fascinant des bactéries ! "
Appéro- Science, qui dit mieux? #cinqascience #5ascience
"Des sphères aux spirales, des extrémophiles aux probiotiques: plongez dans l’univers fascinant des bactéries ! "
Appéro- Science, qui dit mieux? #cinqascience #5ascience
May 29, 2025 at 2:33 AM
Allo Montreal, 11 juin –18H au café La brassée:
"Des sphères aux spirales, des extrémophiles aux probiotiques: plongez dans l’univers fascinant des bactéries ! "
Appéro- Science, qui dit mieux? #cinqascience #5ascience
"Des sphères aux spirales, des extrémophiles aux probiotiques: plongez dans l’univers fascinant des bactéries ! "
Appéro- Science, qui dit mieux? #cinqascience #5ascience
Reposted by Frédérique Le Roux
commemorating pride from the clinical microbiology lab
June 1, 2025 at 7:27 PM
commemorating pride from the clinical microbiology lab
Reposted by Frédérique Le Roux
And I've written a few reviews on the subject over the years, but this one is pretty short, so why not start there ;)
www.sciencedirect.com/science/arti...
www.sciencedirect.com/science/arti...
How clonal are bacteria over time?
Bacteria and archaea reproduce clonally (vertical descent), but exchange genes by recombination (horizontal transfer). Recombination allows adaptive m…
www.sciencedirect.com
May 29, 2025 at 6:58 PM
And I've written a few reviews on the subject over the years, but this one is pretty short, so why not start there ;)
www.sciencedirect.com/science/arti...
www.sciencedirect.com/science/arti...
Allo Montreal, 11 juin –18H au café La brassée:
"Des sphères aux spirales, des extrémophiles aux probiotiques: plongez dans l’univers fascinant des bactéries ! "
Appéro- Science, qui dit mieux? #cinqascience #5ascience
"Des sphères aux spirales, des extrémophiles aux probiotiques: plongez dans l’univers fascinant des bactéries ! "
Appéro- Science, qui dit mieux? #cinqascience #5ascience
May 29, 2025 at 2:33 AM
Allo Montreal, 11 juin –18H au café La brassée:
"Des sphères aux spirales, des extrémophiles aux probiotiques: plongez dans l’univers fascinant des bactéries ! "
Appéro- Science, qui dit mieux? #cinqascience #5ascience
"Des sphères aux spirales, des extrémophiles aux probiotiques: plongez dans l’univers fascinant des bactéries ! "
Appéro- Science, qui dit mieux? #cinqascience #5ascience
Reposted by Frédérique Le Roux
🧬 Bacteria fight both antibiotics and viruses with the same genetic tool: integrons!
New study (Institut Pasteur, CNRS, Université Paris Cité & Montréal): ~10% of gene cassettes may defend against phages.
🛠️ One step closer to smarter therapies.
🔗 www.pasteur.fr/en/research-...
New study (Institut Pasteur, CNRS, Université Paris Cité & Montréal): ~10% of gene cassettes may defend against phages.
🛠️ One step closer to smarter therapies.
🔗 www.pasteur.fr/en/research-...
May 22, 2025 at 8:04 AM
🧬 Bacteria fight both antibiotics and viruses with the same genetic tool: integrons!
New study (Institut Pasteur, CNRS, Université Paris Cité & Montréal): ~10% of gene cassettes may defend against phages.
🛠️ One step closer to smarter therapies.
🔗 www.pasteur.fr/en/research-...
New study (Institut Pasteur, CNRS, Université Paris Cité & Montréal): ~10% of gene cassettes may defend against phages.
🛠️ One step closer to smarter therapies.
🔗 www.pasteur.fr/en/research-...
Reposted by Frédérique Le Roux
Exciting news!! Our latest paper is out in Nat. Microbiol. @natmicrobiol.nature.com
We show that a sub-lineage of 7th pandemic V. cholerae has acquired mobile genetic elements packed with phage defense systems—rendering it multi-phage resistant 😳 ..... 1/3
www.nature.com/articles/s41...
We show that a sub-lineage of 7th pandemic V. cholerae has acquired mobile genetic elements packed with phage defense systems—rendering it multi-phage resistant 😳 ..... 1/3
www.nature.com/articles/s41...
West African–South American pandemic Vibrio cholerae encodes multiple distinct phage defence systems - Nature Microbiology
The West African–South American lineage of Vibrio cholerae contains multiple distinct anti-phage defence systems that provide resistance to various phage families, including vibriophage ICP1, a key pr...
www.nature.com
May 22, 2025 at 6:14 PM
Exciting news!! Our latest paper is out in Nat. Microbiol. @natmicrobiol.nature.com
We show that a sub-lineage of 7th pandemic V. cholerae has acquired mobile genetic elements packed with phage defense systems—rendering it multi-phage resistant 😳 ..... 1/3
www.nature.com/articles/s41...
We show that a sub-lineage of 7th pandemic V. cholerae has acquired mobile genetic elements packed with phage defense systems—rendering it multi-phage resistant 😳 ..... 1/3
www.nature.com/articles/s41...
Allo Montréal, prochain Cinq à Science, 14 mai, le microbiote intestinal par Corinne Maurice, mc Gills 🙂
May 13, 2025 at 12:16 AM
Allo Montréal, prochain Cinq à Science, 14 mai, le microbiote intestinal par Corinne Maurice, mc Gills 🙂
Reposted by Frédérique Le Roux
Have also a look at our back-to-back study for mobile integrons by Nicolas Kieffer from @jaescudero.bsky.social group !
www.science.org/doi/10.1126/...
+ a similar story in V. parahaemolyticus by @landongetz.bsky.social from @themaxwelllab.bsky.social
www.nature.com/articles/s41...
www.science.org/doi/10.1126/...
+ a similar story in V. parahaemolyticus by @landongetz.bsky.social from @themaxwelllab.bsky.social
www.nature.com/articles/s41...
Mobile integrons encode phage defense systems
Integrons are bacterial genetic elements that capture, stockpile, and modulate the expression of genes encoded in integron cassettes. Mobile integrons (MIs) are borne on plasmids, acting as a vehicle ...
www.science.org
May 9, 2025 at 11:41 AM
Have also a look at our back-to-back study for mobile integrons by Nicolas Kieffer from @jaescudero.bsky.social group !
www.science.org/doi/10.1126/...
+ a similar story in V. parahaemolyticus by @landongetz.bsky.social from @themaxwelllab.bsky.social
www.nature.com/articles/s41...
www.science.org/doi/10.1126/...
+ a similar story in V. parahaemolyticus by @landongetz.bsky.social from @themaxwelllab.bsky.social
www.nature.com/articles/s41...
Reposted by Frédérique Le Roux
An enormous thanks for the great co-first author @eloilittner.bsky.social and for our supervisors @celineloot.bsky.social @epcrocha.bsky.social @amazeld.bsky.social @fredoleroux.bsky.social. Many thanks to all co-authors !!
May 9, 2025 at 11:41 AM
An enormous thanks for the great co-first author @eloilittner.bsky.social and for our supervisors @celineloot.bsky.social @epcrocha.bsky.social @amazeld.bsky.social @fredoleroux.bsky.social. Many thanks to all co-authors !!
Reposted by Frédérique Le Roux
On the bioinformatic side, eloilittner.bsky.social found a diverse arsenal of anti-phage defenses in SCIs. Strikingly, systems in integrons are always compact (< 3 genes), and smaller than their homologs outside integrons (likely due to cassette size constraints)
May 9, 2025 at 11:41 AM
On the bioinformatic side, eloilittner.bsky.social found a diverse arsenal of anti-phage defenses in SCIs. Strikingly, systems in integrons are always compact (< 3 genes), and smaller than their homologs outside integrons (likely due to cassette size constraints)
Reposted by Frédérique Le Roux
The integron of our favorite model Vibrio cholerae was mostly “dark matter” as most cassettes had no known role. We found this intriguing and cloned 88 cassettes, testing them for phage resistance. We found 16 defensive cassettes and named the systems after gallic mythology
May 9, 2025 at 11:41 AM
The integron of our favorite model Vibrio cholerae was mostly “dark matter” as most cassettes had no known role. We found this intriguing and cloned 88 cassettes, testing them for phage resistance. We found 16 defensive cassettes and named the systems after gallic mythology
Reposted by Frédérique Le Roux
White smoke, we have a new pope and also 16 new anti-phages systems in sedentary integrons (SCIs) !
In collaboration with the Rocha lab, we show in our new paper that cassettes of these large platforms encode many known anti-phage defenses, and uncovered 16 new ones.
www.science.org/doi/10.1126/...
In collaboration with the Rocha lab, we show in our new paper that cassettes of these large platforms encode many known anti-phage defenses, and uncovered 16 new ones.
www.science.org/doi/10.1126/...
Sedentary chromosomal integrons as biobanks of bacterial antiphage defense systems
Integrons are genetic systems that drive bacterial adaptation by acquiring, expressing, and shuffling gene cassettes. While mobile integrons are well known for spreading antibiotic resistance genes, t...
www.science.org
May 9, 2025 at 11:41 AM
White smoke, we have a new pope and also 16 new anti-phages systems in sedentary integrons (SCIs) !
In collaboration with the Rocha lab, we show in our new paper that cassettes of these large platforms encode many known anti-phage defenses, and uncovered 16 new ones.
www.science.org/doi/10.1126/...
In collaboration with the Rocha lab, we show in our new paper that cassettes of these large platforms encode many known anti-phage defenses, and uncovered 16 new ones.
www.science.org/doi/10.1126/...
Reposted by Frédérique Le Roux
Habemus paper! Our story on integron-encoded anti-phage defenses is now out in @science.org! 16 new systems, small versions of known ones, and a lot more in this highly-collaborative study.
Many thanks to everyone involved, especially my supervisor @epcrocha.bsky.social
bsky.app/profile/bapt...
Many thanks to everyone involved, especially my supervisor @epcrocha.bsky.social
bsky.app/profile/bapt...
White smoke, we have a new pope and also 16 new anti-phages systems in sedentary integrons (SCIs) !
In collaboration with the Rocha lab, we show in our new paper that cassettes of these large platforms encode many known anti-phage defenses, and uncovered 16 new ones.
www.science.org/doi/10.1126/...
In collaboration with the Rocha lab, we show in our new paper that cassettes of these large platforms encode many known anti-phage defenses, and uncovered 16 new ones.
www.science.org/doi/10.1126/...
Sedentary chromosomal integrons as biobanks of bacterial antiphage defense systems
Integrons are genetic systems that drive bacterial adaptation by acquiring, expressing, and shuffling gene cassettes. While mobile integrons are well known for spreading antibiotic resistance genes, t...
www.science.org
May 9, 2025 at 11:51 AM
Habemus paper! Our story on integron-encoded anti-phage defenses is now out in @science.org! 16 new systems, small versions of known ones, and a lot more in this highly-collaborative study.
Many thanks to everyone involved, especially my supervisor @epcrocha.bsky.social
bsky.app/profile/bapt...
Many thanks to everyone involved, especially my supervisor @epcrocha.bsky.social
bsky.app/profile/bapt...
Allo Montréal! Prochain Cinq à Science, le 14 mai, 6pm, Corinne Maurice, Mc Gill, Microbiote intestinal. #cinqascience
May 3, 2025 at 4:58 PM
Allo Montréal! Prochain Cinq à Science, le 14 mai, 6pm, Corinne Maurice, Mc Gill, Microbiote intestinal. #cinqascience
Pas de recul. / No retreat.
Pas de silence. / No silence.
Pas de haine chez nous. / No hate here.
🇨🇦 Liberté, justice, solidarité. / 🇨🇦 Freedom, justice, solidarity.
Résistons ensemble! ✊ / Let’s resist together! ✊
#CanadaLibre #DefendDemocracy #LoveWins
Pas de silence. / No silence.
Pas de haine chez nous. / No hate here.
🇨🇦 Liberté, justice, solidarité. / 🇨🇦 Freedom, justice, solidarity.
Résistons ensemble! ✊ / Let’s resist together! ✊
#CanadaLibre #DefendDemocracy #LoveWins
April 29, 2025 at 2:38 AM
Pas de recul. / No retreat.
Pas de silence. / No silence.
Pas de haine chez nous. / No hate here.
🇨🇦 Liberté, justice, solidarité. / 🇨🇦 Freedom, justice, solidarity.
Résistons ensemble! ✊ / Let’s resist together! ✊
#CanadaLibre #DefendDemocracy #LoveWins
Pas de silence. / No silence.
Pas de haine chez nous. / No hate here.
🇨🇦 Liberté, justice, solidarité. / 🇨🇦 Freedom, justice, solidarity.
Résistons ensemble! ✊ / Let’s resist together! ✊
#CanadaLibre #DefendDemocracy #LoveWins
🚨 Postdoc Alert!
Join my lab @ Montréal’s Faculty of Medicine via the 2025 CIB Fellowship Competition 🧬
Project: “The Paradox of Parasitism” – bioinformatics + marine parasite evolution
💸 $63,819/yr + full benefits (2 yrs)
Apply 👉 cibmontreal.ca/en/news/laun...
Join my lab @ Montréal’s Faculty of Medicine via the 2025 CIB Fellowship Competition 🧬
Project: “The Paradox of Parasitism” – bioinformatics + marine parasite evolution
💸 $63,819/yr + full benefits (2 yrs)
Apply 👉 cibmontreal.ca/en/news/laun...
Launch of the 2025 postdoctoral fellowship competition
The BIC is proud to launch its first Postdoctoral Fellowship competition. Applications are open from now until May 27, 2025.
cibmontreal.ca
April 24, 2025 at 10:31 PM
🚨 Postdoc Alert!
Join my lab @ Montréal’s Faculty of Medicine via the 2025 CIB Fellowship Competition 🧬
Project: “The Paradox of Parasitism” – bioinformatics + marine parasite evolution
💸 $63,819/yr + full benefits (2 yrs)
Apply 👉 cibmontreal.ca/en/news/laun...
Join my lab @ Montréal’s Faculty of Medicine via the 2025 CIB Fellowship Competition 🧬
Project: “The Paradox of Parasitism” – bioinformatics + marine parasite evolution
💸 $63,819/yr + full benefits (2 yrs)
Apply 👉 cibmontreal.ca/en/news/laun...