Melanie Blokesch
@mblokesch.bsky.social
Professor of Life Sciences & Director Global Health Institute @EPFL_en. Passionate about science 🤩 Views are my own.
3rd lab meeting I’m presenting at this year! After two during my sabbatical on my experiments (Helaine & Mekalanos labs), today finally in MY OWN lab 🎉
So much fun to share new work done w/ fantastic technicians Laurie, Sandrine, Loriane & bioinformatician Alexandre.
Bonus: cake served by the lab 🍰
So much fun to share new work done w/ fantastic technicians Laurie, Sandrine, Loriane & bioinformatician Alexandre.
Bonus: cake served by the lab 🍰
October 2, 2025 at 12:34 PM
3rd lab meeting I’m presenting at this year! After two during my sabbatical on my experiments (Helaine & Mekalanos labs), today finally in MY OWN lab 🎉
So much fun to share new work done w/ fantastic technicians Laurie, Sandrine, Loriane & bioinformatician Alexandre.
Bonus: cake served by the lab 🍰
So much fun to share new work done w/ fantastic technicians Laurie, Sandrine, Loriane & bioinformatician Alexandre.
Bonus: cake served by the lab 🍰
Water everywhere 😜 - with Mario @feldmanlab.bsky.social & Amy @flamycain.bsky.social at Acinetobacter conference in Niagara Falls
July 8, 2025 at 7:52 PM
Water everywhere 😜 - with Mario @feldmanlab.bsky.social & Amy @flamycain.bsky.social at Acinetobacter conference in Niagara Falls
Had a fabulous day at the Wadsworth Center in Albany yesterday 🤩 Very impressive place to do science plus everybody is so kind 🤗
Thanks so much Sian @sianowen.bsky.social and Tom Bartlett for the kind invitation 🤩. Glad to see your new labs started so well.
Thanks so much Sian @sianowen.bsky.social and Tom Bartlett for the kind invitation 🤩. Glad to see your new labs started so well.
June 28, 2025 at 2:18 AM
Had a fabulous day at the Wadsworth Center in Albany yesterday 🤩 Very impressive place to do science plus everybody is so kind 🤗
Thanks so much Sian @sianowen.bsky.social and Tom Bartlett for the kind invitation 🤩. Glad to see your new labs started so well.
Thanks so much Sian @sianowen.bsky.social and Tom Bartlett for the kind invitation 🤩. Glad to see your new labs started so well.
Yeahhh 🎊🎉👏🎈 - congrats again, Prof. McKitterick 🤩
June 25, 2025 at 12:43 AM
Yeahhh 🎊🎉👏🎈 - congrats again, Prof. McKitterick 🤩
…including against 16 (!) tested isolates of ICP1—the primary predator of pandemic V. cholerae 🦠— as well as the common vibriophage X29.
In fact, this is one of the very few studies primarily focused on defense systems in their native bacterial host and mostly at native expression levels 🤩.....2/3
In fact, this is one of the very few studies primarily focused on defense systems in their native bacterial host and mostly at native expression levels 🤩.....2/3
May 22, 2025 at 6:14 PM
…including against 16 (!) tested isolates of ICP1—the primary predator of pandemic V. cholerae 🦠— as well as the common vibriophage X29.
In fact, this is one of the very few studies primarily focused on defense systems in their native bacterial host and mostly at native expression levels 🤩.....2/3
In fact, this is one of the very few studies primarily focused on defense systems in their native bacterial host and mostly at native expression levels 🤩.....2/3
Join the Blokesch lab (@EPFL) as a postdoc in Molecular Microbiology 🤩
Study Vibrio cholerae defense systems (phage/plasmid) in a dynamic, collaborative environment in Lausanne close to Lake Geneva in 🇨🇭!
Please visit my lab's webpage for details about the position and how to formally apply.
Study Vibrio cholerae defense systems (phage/plasmid) in a dynamic, collaborative environment in Lausanne close to Lake Geneva in 🇨🇭!
Please visit my lab's webpage for details about the position and how to formally apply.
April 25, 2025 at 4:15 PM
Join the Blokesch lab (@EPFL) as a postdoc in Molecular Microbiology 🤩
Study Vibrio cholerae defense systems (phage/plasmid) in a dynamic, collaborative environment in Lausanne close to Lake Geneva in 🇨🇭!
Please visit my lab's webpage for details about the position and how to formally apply.
Study Vibrio cholerae defense systems (phage/plasmid) in a dynamic, collaborative environment in Lausanne close to Lake Geneva in 🇨🇭!
Please visit my lab's webpage for details about the position and how to formally apply.
LmuA is toxic when expressed from plasmid, DdmA expression only slightly impacts growth (LmuACB is, in general, more toxic than DdmABC under the tested conditions). Both are toxic when N-terminus is forced to dimerize by fusing it to cJun, as shown in preprint 🤩.
March 16, 2025 at 12:53 PM
LmuA is toxic when expressed from plasmid, DdmA expression only slightly impacts growth (LmuACB is, in general, more toxic than DdmABC under the tested conditions). Both are toxic when N-terminus is forced to dimerize by fusing it to cJun, as shown in preprint 🤩.
Finished it the same evening 🤗 ....
Ok, was 5am in the morning (when I am focused, I cannot stop!) - but hey, 1000 pieces after all 🤩
Ok, was 5am in the morning (when I am focused, I cannot stop!) - but hey, 1000 pieces after all 🤩
January 5, 2025 at 1:21 PM
Finished it the same evening 🤗 ....
Ok, was 5am in the morning (when I am focused, I cannot stop!) - but hey, 1000 pieces after all 🤩
Ok, was 5am in the morning (when I am focused, I cannot stop!) - but hey, 1000 pieces after all 🤩
Preparing for my sabbatical 😂 - didn’t get far yet ….
December 29, 2024 at 6:00 PM
Preparing for my sabbatical 😂 - didn’t get far yet ….
Wrapping up admin tasks 📄🧑💻 to avoid carrying them into the new year 🙄, but couldn’t resist testing a new phage against a "few" V. cholerae strains 🧫🧪 on the side.
Love being in the lab—where I’ll be spending lots of time during my 2025 sabbatical... Yippee! 🤩
Wishing everyone Happy Holidays! 🎄🎆
Love being in the lab—where I’ll be spending lots of time during my 2025 sabbatical... Yippee! 🤩
Wishing everyone Happy Holidays! 🎄🎆
December 21, 2024 at 12:18 PM
Wrapping up admin tasks 📄🧑💻 to avoid carrying them into the new year 🙄, but couldn’t resist testing a new phage against a "few" V. cholerae strains 🧫🧪 on the side.
Love being in the lab—where I’ll be spending lots of time during my 2025 sabbatical... Yippee! 🤩
Wishing everyone Happy Holidays! 🎄🎆
Love being in the lab—where I’ll be spending lots of time during my 2025 sabbatical... Yippee! 🤩
Wishing everyone Happy Holidays! 🎄🎆
We think that the acquisition of these two defense-conferring MGEs in Africa provided a multi-phage resistance phenotype, likely allowing the strains to evade local vibriophages. This may have driven the proliferation of the lineage in Africa and/or facilitated its transfer to South America.....17/n
November 25, 2024 at 2:27 PM
We think that the acquisition of these two defense-conferring MGEs in Africa provided a multi-phage resistance phenotype, likely allowing the strains to evade local vibriophages. This may have driven the proliferation of the lineage in Africa and/or facilitated its transfer to South America.....17/n
Importantly, expressing the three novel defense systems individually in E. coli (single copy, low expression) conferred significant resistance to over 60% of the >70 phages in the BASEL collection, showcasing their broad protective capabilities.... 15/n
November 25, 2024 at 2:27 PM
Importantly, expressing the three novel defense systems individually in E. coli (single copy, low expression) conferred significant resistance to over 60% of the >70 phages in the BASEL collection, showcasing their broad protective capabilities.... 15/n
We next examined the second WASA lineage-specific mobile element: the VSP-II variant. Despite the lack of prior predictions, we identified two additional phage defense systems. ......13/n
November 25, 2024 at 2:27 PM
We next examined the second WASA lineage-specific mobile element: the VSP-II variant. Despite the lack of prior predictions, we identified two additional phage defense systems. ......13/n
How does WonAB protect cells from ICP1? Using extensive experiments—including genetics, growth dynamics, and live-cell imaging—we demonstrated that WonAB triggers growth arrest, functioning as an 'abortive infection' system. This strategy sacrifices individual cells to protect the population....12/n
November 25, 2024 at 2:27 PM
How does WonAB protect cells from ICP1? Using extensive experiments—including genetics, growth dynamics, and live-cell imaging—we demonstrated that WonAB triggers growth arrest, functioning as an 'abortive infection' system. This strategy sacrifices individual cells to protect the population....12/n
Bioinformatics analyses of the two wonAB-encoded proteins revealed motifs and DUFs typical of other defense systems—but not in this unique combination. Using AlphaFold, we also predicted their structures, offering further insights into their potential mechanism of action.......10/n
November 25, 2024 at 2:27 PM
Bioinformatics analyses of the two wonAB-encoded proteins revealed motifs and DUFs typical of other defense systems—but not in this unique combination. Using AlphaFold, we also predicted their structures, offering further insights into their potential mechanism of action.......10/n
So, which genes drive the resistance phenotype?
Since no predicted phage defense systems were identified within WASA-1, we systematically deleted regions of interest. This approach led us to uncover a two-gene cluster responsible for the resistance, now named wonAB ....9/n
Since no predicted phage defense systems were identified within WASA-1, we systematically deleted regions of interest. This approach led us to uncover a two-gene cluster responsible for the resistance, now named wonAB ....9/n
November 25, 2024 at 2:27 PM
So, which genes drive the resistance phenotype?
Since no predicted phage defense systems were identified within WASA-1, we systematically deleted regions of interest. This approach led us to uncover a two-gene cluster responsible for the resistance, now named wonAB ....9/n
Since no predicted phage defense systems were identified within WASA-1, we systematically deleted regions of interest. This approach led us to uncover a two-gene cluster responsible for the resistance, now named wonAB ....9/n
Sure enough, when we deleted the WASA-1 element in the Peruvian isolates, the strains lost their ICP1 resistance.
Conversely, transferring WASA-1 to other susceptible 7PET strains rendered them fully resistant to ICP1, confirming its role in phage defense....8/n
Conversely, transferring WASA-1 to other susceptible 7PET strains rendered them fully resistant to ICP1, confirming its role in phage defense....8/n
November 25, 2024 at 2:27 PM
Sure enough, when we deleted the WASA-1 element in the Peruvian isolates, the strains lost their ICP1 resistance.
Conversely, transferring WASA-1 to other susceptible 7PET strains rendered them fully resistant to ICP1, confirming its role in phage defense....8/n
Conversely, transferring WASA-1 to other susceptible 7PET strains rendered them fully resistant to ICP1, confirming its role in phage defense....8/n
The results were striking: Strains isolated in the 1990s in Peru showed strong resistance to ICP1-2006. Notably, this resistance extended to other ICP1 isolates as well, highlighting a robust defense mechanism....4/n
November 25, 2024 at 2:27 PM
The results were striking: Strains isolated in the 1990s in Peru showed strong resistance to ICP1-2006. Notably, this resistance extended to other ICP1 isolates as well, highlighting a robust defense mechanism....4/n
We started by testing the susceptibility of 7th pandemic V. cholerae (7PET) strains against a panel of well-characterized Vibrio phages: ICP1, ICP2 & ICP3. These phages, named by Kim Seed & Andy Camilli, have been pivotal in understanding V. cholerae phage dynamics ...3/n
doi.org/10.1128/mbio...
doi.org/10.1128/mbio...
November 25, 2024 at 2:27 PM
We started by testing the susceptibility of 7th pandemic V. cholerae (7PET) strains against a panel of well-characterized Vibrio phages: ICP1, ICP2 & ICP3. These phages, named by Kim Seed & Andy Camilli, have been pivotal in understanding V. cholerae phage dynamics ...3/n
doi.org/10.1128/mbio...
doi.org/10.1128/mbio...
We aimed at uncovering novel defense systems in the 7th pandemic Vibrio cholerae lineage—the pathogen behind the ongoing cholera pandemic that started in 1961. The lineage has caused cholera outbreaks across the globe. Identifying key factors behind its success is therefore of prime importance...2/n
November 25, 2024 at 2:27 PM
We aimed at uncovering novel defense systems in the 7th pandemic Vibrio cholerae lineage—the pathogen behind the ongoing cholera pandemic that started in 1961. The lineage has caused cholera outbreaks across the globe. Identifying key factors behind its success is therefore of prime importance...2/n
After winter break w/ family & friends and lots of love 🫶, sleep 😴, and food 🙄, I welcome 2024 by propagating phages 🤓.
Was already homesick for my lab + am truly enjoying the quietness today. What a luxury to have time for research w/out meetings, committees, teaching,... 🧫🦠
Was already homesick for my lab + am truly enjoying the quietness today. What a luxury to have time for research w/out meetings, committees, teaching,... 🧫🦠
January 1, 2024 at 1:51 PM
After winter break w/ family & friends and lots of love 🫶, sleep 😴, and food 🙄, I welcome 2024 by propagating phages 🤓.
Was already homesick for my lab + am truly enjoying the quietness today. What a luxury to have time for research w/out meetings, committees, teaching,... 🧫🦠
Was already homesick for my lab + am truly enjoying the quietness today. What a luxury to have time for research w/out meetings, committees, teaching,... 🧫🦠
Collectively, the data let us conclude that T4P-mediated contact can lead to T6SS killing but that auto-aggregation & therefore segregation can also protect from such attacks. Bravo to all co-authors 🎉👏 Simon, Richard, Alexandre & Anne-Flo - and we hope you like the study 🤩 ... 14/end
October 28, 2023 at 1:48 PM
Collectively, the data let us conclude that T4P-mediated contact can lead to T6SS killing but that auto-aggregation & therefore segregation can also protect from such attacks. Bravo to all co-authors 🎉👏 Simon, Richard, Alexandre & Anne-Flo - and we hope you like the study 🤩 ... 14/end
.... which let us better understand the factors that enable or hinder the T6SS’s impact on piliated competitors ...... 13/n
October 28, 2023 at 1:47 PM
.... which let us better understand the factors that enable or hinder the T6SS’s impact on piliated competitors ...... 13/n
To better understand this phenomenon, we asked Anne-Florence Bitbol for help. She and her PhD student Richard Servajean developed a physics-grounded computational model for auto-aggregation 💻.... 12/n
October 28, 2023 at 1:46 PM
To better understand this phenomenon, we asked Anne-Florence Bitbol for help. She and her PhD student Richard Servajean developed a physics-grounded computational model for auto-aggregation 💻.... 12/n
But what happened when the predator and prey's pili were non-identical? => Almost no killing given spatial segregation of predator and prey (there are always a few unlucky cells in the wrong aggregate 😜) ....11/n
October 28, 2023 at 1:45 PM
But what happened when the predator and prey's pili were non-identical? => Almost no killing given spatial segregation of predator and prey (there are always a few unlucky cells in the wrong aggregate 😜) ....11/n