SFM Microbial Pathogenesis

Excessive Ca²⁺ signaling fuels inflammation in a zebrafish model of #cysticfibrosis, and verapamil, an FDA-approved Ca²⁺ channel blocker, restores balance & limits inflammation, new study reveals. A promising repurposing opportunity for CF therapy!
📖 shorturl.at/Fxg9F
✍️ @sarahdja.bsky.social & coll.

@umontreal-en.bsky.social @pasteur.fr @sbroscoff.bsky.social @cnrs.fr @ifremer.bsky.social @umontpellier.bsky.social

Phages are not always fast-evolving chaos machines. In an oyster farm, Vibrio phages stayed genetically identical for 4 yrs, showing surprising viral stability shaped by nested ecology & mobile genetic elements.

✍️ @fredoleroux.bsky.social @epcrocha.bsky.social & coll.
📖 shorturl.at/Nq8G1
#MicroSky

tRNA-modification mutants in mycobacteria boost antibiotic recalcitrance by activating WhiB7 & coupling alanine metabolism to ribosome rescue and survival, new study reveals.

✍️ @jvaubourgeix.bsky.social & coll.
📖 shorturl.at/86JTs

#MicroSky #AMR #RNAsky
@imperialcollegeldn.bsky.social @inserm.fr

Staphylococcus aureus EVs are more than cargo carriers, they’re immune modulators. New work on MRSA N315 EVs reveals selective uptake, RNA release, and activation of TLR and NOD2 signaling.

✍️ Julia Papail, Eric Guédon & coll.
@inrae-bzhndie.bsky.social
📖 shorturl.at/EuXh0
#MicroSky #Staphylococcus

New study suggests fetal brain vulnerability to Oropouche virus (OROV) in early pregnancy: Epidemic-related strain infects human neural progenitors & brain organoids, causing proliferation arrest, apoptosis & loss of brain architecture.
#Virology
✍️ Alexandra Albert & coll.
📖 shorturl.at/nhO8F

Revisited model of PZA/HPOA efficacy, supporting a pH-dependent mechanism of weak acid permeation and cytosolic acidification as main mechanism of bactericidal activity. In this model, the authors propose that the presence of glycerol potentiates PZA/HPOA efficacy by generating acidic intermediates that lower IBpH. Accordingly, β-alanine and pantothenate might mitigate this effect by acting as buffering molecules that alleviate acidosis. Finally, PanD enzymatic activity consumes protons which in turn increases IBpH. Therefore, in this model PanD minimally contributes to PZA tolerance and cannot be considered as the primary target of the drug.

New study shows pyrazinamide kills TB by acidifying bacterial cytosol — not via PanD/CoA depletion. A long-standing debate settled, paving the way for smarter PZA-like drugs. #MicroSky

✍️ J. Laudouze, Y. Antonenko, @alexandregouzy.bsky.social, @pierresantucci.bsky.social & coll.
📖 shorturl.at/tuz6Q

Inorganic sulfate is critical for Mycobacterium tuberculosis lung tissue colonization and redox balance | PNAS Tuberculosis remains the deadliest infectious disease caused by a single pathogen, highlighting the urgent need for novel therapies. A deeper under...

Excited to share Wendy Le Mouëllic’s PhD work, now published in @pnas.org!
It reveals that M. tuberculosis depends on inorganic sulfate import to survive inside host cells—fueling essential processes such as redox balance and stress resistance.
Huge congrats to Wendy & colleagues!
shorturl.at/WbFQC

Turns out even kings had ordinary mouths. A new study of King Richard III’s dental calculus shows his oral microbiome wasn’t so different from the common folk’s, despite a royal diet and lifestyle. #AncientDNA #Microbiome #MicroSky

Mycobacterium tuberculosis forms nitrate-induced intracytoplasmic membranes (MIMs) that rewire metabolism & dampen inflammation during infection, uncovering a new layer of bacterial adaptation!
✍️ @camimille.bsky.social @enningalab.bsky.social @pasteur.fr
📖 shorturl.at/9kbDM

We are looking to hire post-docs to work on T cell responses to M. tuberculosis infection using murine and NHP models. If you know T cells and wanna work on the top global infectious killer check us out. BSL3 experience not required. The NIH intramural program in Bethesda MD is an amazing place!

Streptococcus pneumoniae can induce competence via the ClpX/ClpP protease through the RipA toxin, which stresses replication and activates comCDE. Metabolically active but dying cells release CSP, spreading competence to neighbors.
#MicroSky
✍️ @polardlab.bsky.social & coll.
📖 shorturl.at/E9ael

Listeria monocytogenes doesn’t just rush to the cytosol. It can replicate in permeated epithelial phagosomes lacking cathepsin D, where LLO sustains growth, PlcB drives escape, and the PrfA program is primed.
✍️ @alicelebreton.bsky.social & coll. @ibensens.bsky.social
📖 shorturl.at/1bFph

#Dengue virus slips infection-boosting RNAs into mosquito saliva by hitching a ride in EVs, a study finds. The viral RNA hooks onto a mosquito protein, AeSyntenin, to get packaged and released.
#MicroSky #Virology

✍️ @julienpompon.bsky.social & coll.
@ird-fr.bsky.social
📖 shorturl.at/lxUyw

A two year post-doctoral position at the BacterialGenome Plasticity Unit starting October 1st - Research

A 2-year postdoc position in my lab, under the supervision of P-Alex Kaminski, on Z-DNA phages and the benefit given by ZTGC DNA and the replication machinery, with attempt to create a Z based minireplicon
research.pasteur.fr/en/job/a-two...

@cascaleslab.bsky.social

New study reveals a CD38-like ADP-ribosyl cyclase toxin delivered by T6SS that depletes NAD+ in both bacterial and eukaryotic cells.
A striking case of structural mimicry, cross-immunity, and widespread deployment in microbial warfare.
✍️‪ @jmartinkus.bsky.social & coll.
📖 shorturl.at/b5LSB
#MicroSky

We have an open engineer position to work on type IX secretion (T9SS), under the supervision of @doan_thierry (collab with HP Fierobe & A. Tolonen). 1-year contract, renewable up to 3.5 years. Please apply here or forward to anyone potentially interested:

emploi.cnrs.fr/Offres/CDD/U...

A new study delivers the most comprehensive phylogenomic analysis of Spirochaetes to date, revealing their deep evolutionary roots and shedding light on the loss of spiral morphology and host adaptation.
✍️ @microbiomol.bsky.social and coll. @pasteur.fr
📖 shorturl.at/UxAWu
#MicroSky

E. coli and P. aeruginosa need the Hsp90 chaperone to produce key virulence factors colibactin & pyoverdine, study reveals. Hsp90 stabilizes megasynthases behind complex metabolite biosynthesis. New angles on infection control & biotech tools!
📖 shorturl.at/n1Pu6
✍️ Fratacci, Chaouche & coll. #IMM

New insights into Shigella flexneri pathogenesis: the VapBC TA system is activated during intracellular infection, coordinating stress adaptation, T3SS-mediated virulence, and immune evasion, new study reveals.

✍️ E. Saifi & coll. @inem-necker.bsky.social @pasteur.fr
📖 shorturl.at/26d33
#MicroSky

A new path in the fight against AMR!
Using B cells from CF patients, researchers isolated human mAbs targeting the T3SS of P. aeruginosa. Structural & functional data reveal distinct neutralization modes, blocking virulence without antibiotics! #MicroSky
✍️ ‪JM Desveaux @ coll.
📖 shorturl.at/2hixd

A prophage-encoded single-stranded DNA-binding protein (SSBP) from S. aureus attenuates bacterial virulence and enhances macrophage activation via IL-6, new study reveals. SSBP boosts immune clearance and shows therapeutic potential. #MicroSky #Phage
✍️ Ahmad-Mansour & coll.
📖 shorturl.at/6yqFx

Dynamic excision of the F13 hlb-converting prophage in Staph. aureus is critical for full virulence, new study reveals. Loss of F13 restores β-hemolysin expression and enhances pathogenicity, while locking the prophage impairs infection. #MicroSky
✍️ O. Poupel & coll @pasteur.fr
📖 shorturl.at/F1W3t

Uropathogenic E. coli uses a novel two-gene system, DanRI, to outsmart neutrophils by blocking NETs and ROS. Induced by host nucleosomes, DanRI boosts bacterial survival & persistence. A new twist in immune evasion!
✍️ @doracerina.bsky.social & coll.
📖 shorturl.at/cAj05
#MicroSky

Nearly half of bacteria carry mobile, accessory PDF enzymes that can resist actinonin, new study reveals. Resistance to PDF-targeting antibiotics is already encoded and poised to spread.
#AMR #MicroSky
✍️ @morgan-lamberioux.bsky.social and coll.
@pasteur.fr
📖 shorturl.at/WTBVx

New study reshapes our view of sleeping sickness: #Trypanosoma brucei persists in fatty skin tissues and uses host-derived glycerol to get transmission-ready, even when blood levels are low.
#SleepingSickness #ScienceNews #Parasites
✍️F. Bringaud & coll.
📖https://shorturl.at/LGGxk

Antibiotics disrupt gut microbes, but what about their viruses?
A new study finds that gut phages crash, bloom, and bounce back after antibiotics, helping restore microbial balance via kill-the-winner dynamics.
✍️ @eugenpfeifer.bsky.social & coll.
📖 shorturl.at/AtafX
#MicroSky #AMR

🚨My new team at @ipbstoulouse.bsky.social in France currently have an open, fully-funded PhD position 🧑‍🔬👩‍🔬to study membrane proteins & transporters of therapeutic interest using cryo-EM & biophysics.🧊🔬🦠

#StructuralBiology #MicroSky

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For more details 👇

I will be recruiting new postdocs with start dates end 2025 - early 2026. If you'd like to work at the Pasteur Institute in the heart of Paris surrounded by amazing scientists, reach out to discuss possible projects on SynBio / Bacterial Immunity!