Dr. Alexander Pastora

Exciting news! 🎉 In Jan 2026, I’ll be starting as an Assistant Professor at Mass General Hospital in Boston. The lab will study host–pathogen co-adaptation during chronic lung infections, and how it shapes treatment outcomes and disease progression.

🔗 Check out open positions: meirelleslab.org

Pls share: Hofstra University is looking for a Tenure-Track Microbiologists!
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We are seeking a microbiologist with a research focus on a non-pathogenic bacterial model system.
hofstra.peopleadmin.com/postings/6542

New in JB: Banerjee, Chandler et al. link regulation of QS to the the nitrogen-related phosphotransferase system in P. aeruginosa, and thus virulence in this microbe.
journals.asm.org/doi/10.1128/...
@asm.org #JBacteriology

Registration is open! Come join us at the sensory transduction in microorganisms GRC! Spread the word! www.grc.org/sensory-tran...

Pseudomonas aeruginosa supports the survival of Prevotella melaninogenica in a cystic fibrosis lung polymicrobial community through metabolic cross-feeding | mBio Polymicrobial interactions impact disease outcomes in pwCF who suffer from chronic respiratory infections. Previous work established a CF-relevant polymicrobial community model that allows experimenta...

Happy to finally see this out! Bassam El Halfi (@bassamhafi.bsky.social - my first rotation student when I started my post-doc in @geiselbiofilm.bsky.social) did an amazing job investigating mechanisms of interspecies metabolic interactions. Check it out! #microsky

journals.asm.org/doi/10.1128/...

Excited to share our latest work, driven by my recently graduated PhD student Kaitlyn Barrack, exploring the mechanisms of bacterial dysbiosis in the CF gut - including a role for a colorectal cancer-associated genotoxin in this competition.
www.biorxiv.org/content/10.1...
@kbarrack.bsky.social

Excited about our most recent collaboration with the Wong lab, lead by William Schmidt, describing a T4P and CdrA-mediated mechanism of sensing surface EPS. Fun stuff and great work William and team.
www.nature.com/articles/s41...

Our newest manuscript on the gut-lung axis in CF, lead by Rebecca Valls, explores sex and intestinal regional differences in response to Bacteroides. Check it out!
www.biorxiv.org/content/10.1...

Kenyon is hiring a TT microbiologist! Please share widely. I’m the search chair & am happy to answer any questions. careers.pageuppeople.com/695/cw/en-us...

New in JB: Conaway, Hogan et al. link QS and phosphate metabolism in P. aeruginosa, with implications of pathogenesis.
journals.asm.org/doi/10.1128/...
@asm.org #JBacteriology

Just a reminder to the Biofilms community that the Early Registration period ends today (July 8) for the 10th ASM Conference on Biofilms (Nov 9-13, 2025, Portland, OR) at the lowest prices (asm.org/events/asm-b...). If you've already registered thanks; if not you can still catch these lower rates!

Antagonism as a foraging strategy in microbial communities In natural habitats, nutrient availability limits bacterial growth. We discovered that bacteria can overcome this limitation by acquiring nutrients by lysing neighboring cells through contact-dependen...

Thrilled to share our new paper in @science.org describing our discovery that bacteria can switch from competitors to bonafide predators when resources run dry—arming nanoscale “spears” (T6SS) to stab & consume neighbours.

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

#MicroSKy #Microbiology

The 3rd International #Biosurfactants Conference will take place in Aachen, Germany September 8 -10 2025. Academia and industry will discuss the latest developments, and share cutting-edge insight in this exciting field of microbial #biotechnology #microsky biosurfactants.uni-hohenheim.de/en

Cyclic Di‐AMP Affects Cell Membrane Integrity of Streptococcus pneumoniae When Streptococcus pneumoniae produces low amounts of the second messenger cyclic di-AMP (c-di-AMP), they do not survive in the presence of competence-stimulating peptide (CSP), which is used for tra...

Tiffany Zarrella et al. provide new insights into the role of the bacterial second messenger cyclic di-adenosine monophosphate (c-di-AMP) in maintaining cell envelope homeostasis in Streptococcus pneumoniae.
#MicroSky #cyclic-di-AMP
onlinelibrary.wiley.com/doi/10.1111/...

A get-together of Dartmouth folks at ASM Microbe!
#ASMicrobe

New in JB: Tchadi, Taylor et al. use a heterologous expression system to show that binding of PqsE to RhlR fine-tunes RhlR activity and does so in a promoter-specific fashion.
journals.asm.org/doi/full/10....
@asm.org #JBacteriology

New in JB: Oladosu and Sauer show that FleQ, SagS and BrlR contribute to fine tuning the expression of genes contributing to antibiotic tolerance in P. aeruginosa biofilms.
journals.asm.org/doi/10.1128/...
@asm.org #JBacteriology

Model for the interaction between P. aeruginosa and K. pneumoniae. These bacteria can co-exist in nutrient-replete conditions. Under iron-limiting conditions, siderophore synthesis is induced in both bacteria. Iron limitation can also turn on the synthesis of biosurfactants, rhamnolipids, in P. aeruginosa, allowing it to push away K. pneumoniae.

#MicrobiologyMonday: Pseudomonas aeruginosa releases a surfactant that displaces Klebsiella pneumoniae from solid surfaces. By pushing K. pneumoniae away, the detergent allows P. aeruginosa to better compete for limited iron. Learn more in #mBio: asm.social/2sH

Kaitlyn Barrack, who defended recently, was hooded at the Dartmouth Investiture last Saturday. We got all decked out in our robes!

Bacterial sporulation (endospore formation) is complicated,but it turns out a lot of steps are regulated by classically defined developmental "checkpoints", and not events that are intrinsically required for the next step to occur. Zac Park reviews these in #Bacillus subtilis
doi.org/10.1146/annu...

A molecular conveyor belt-associated protein controls the rotational direction of the bacterial type 9 secretion system | mBio The type 9 secretion system (T9SS) is fundamental to bacterial gliding motility, pathogenesis, and surface colonization. Our findings reveal that the C-terminal region of the conveyor belt-associated ...

Our paper on how a conveyor belt-associated protein of T9SS-driven gliding bacteria acts as a molecular switch, reversing T9SS rotation to fine-tune movement - like a smart conveyor or biological snowmobile adapting to changing terrain is out now in @mbio.bsky.social journals.asm.org/doi/10.1128/...

Phenotypic characterization of RloA protease mutants in Pseudomonas aeruginosa. (A) Biofilm formation in PA14 wild type and ∆rloA1-3 mutants was assessed through crystal violet staining of overnight cultures grown in 0.4% Arginine M63 media (top). Graph shows the normalized average intensity of crystal violet staining (OD550) relative to the growth of the corresponding bacterial culture (OD600), n = 4. Error bars show standard deviation. (B) PA14 wild-type and ∆rloA1-3 mutant colonies were grown in Congo red 0.2% glucose M63 agar. Scale bar represents 2 mm. (C) Ampicillin ETEST strips tested on lawns of PA14 wild-type and ∆rloA1-3 mutant strains grown on Mueller-Hinton agar. Graph shows the average minimal inhibitory concentration (MIC) from triplicate experiments. Error bars show standard deviation. (D) Scanning electron micrographs of PA14 wild-type (top) and ∆rloA1-3 mutant cells (bottom). Scale bar represents 4 µm.

Researchers uncover a new class of retropepsin-like proteases in P. aeruginosa that are required for biofilm formation & bacterial survival under stress conditions, including antibiotic exposure, making them appealing therapeutic targets. #mBio: asm.social/2sq

New in JB: Ziogas, Spatafora et al. show that the metalloregulatory protein SloR binds cooperatively to the promoter of the gene coding for the MntH Mn transporter.
journals.asm.org/doi/10.1128/...
@asm.org #JBacteriology

Two tenure-track positions at Amherst College www.amherst.edu.

apply.interfolio.com/168795 (molecular genetics and biochemistry)
apply.interfolio.com/168794 (molecular/cellular neurobiology)

We have two new positions, a PhD and a Post doc at #InstituteofBiologyLeiden within our @microclockerc.bsky.social #ERCSyG project to discover interaction of #circadianclocks between Bacillus subtilis and Arabidopsis

please share these with your network! 🙏

links below👇
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Two unrelated Pseudomonas aeruginosa phages require the exopolysaccharide Psl for infection

in Research Square (under review in NPJ Biofilms and Microbiomes) from Courtney Reichhardt
with @micheleleroux.bsky.social

www.researchsquare.com/article/rs-6...

Portrait photo of Tanmay Bharat

Congratulations to @tbharat-lab.bsky.social, Group Leader in the LMB’s Structural Studies Division, who has received the Gold Medal from @embo.org for his research on prokaryotic surface molecules.

Read more here: www2.mrc-lmb.cam.ac.uk/tanmay-bhara...

#LMBNews

check out our newest paper in JB: Kuchma, Geiger et al. identify key components of flagellar-mediated surface sensing system of P. aeruginosa.
journals.asm.org/doi/10.1128/...
@asm.org #Jbacteriology

Building microbial communities to improve antimicrobial strategies - npj Antimicrobials and Resistance npj Antimicrobials and Resistance - Building microbial communities to improve antimicrobial strategies

It's finally out! The first (of hopefully, many in the future!) collaborative paper between my lab and @jpcote.bsky.social's lab (a.k.a. the J2P2 group!) over here at @usherbrooke.bsky.social. #microsky

www.nature.com/articles/s44...

Shanice Webster standing confidently in front of tall grasses with a greenhouse in the background.

Plant health is essential to food security, yet pathogens continue to threaten crops worldwide. To better understand how disease takes hold—& how to stop them—HHMI Hanna Gray Fellow @shanice-webster.bsky.social is exploring the dynamic relationships among plants, microbes, & disease-causing agents.