Tiffany Zarrella

Graph of award probability of R35 and R01 from NIH factbook as a function of review rank percentile. As is apparent, 2025 is a significant departure, with lower award probabilities at all scores <40 and significant departures from norm, where even being in the top 10% is no longer a nearly certain indicator of success. Data source: https://report.nih.gov/nihdatabook/report/302

The data is in: the NIH goalposts have shifted.

What were once almost certain fundable scores have become coin flips and what used to be likely grants have become aspirational, leading to fewer awards.

Another manifestation of how HHS policies have led to fewer awards and less science.

Magnesium depletion by Candida albicans unleashes two unusual modes of colistin resistance in Pseudomonas aeruginosa with different fitness costs Bacterial resistance to the vital last-resort antibiotic colistin is an increasing challenge. This study shows that magnesium sequestration by C. albicans enables P. aeruginosa to evolve much higher l...

Our story on the evolution of colistin resistance is just out on @plosbiology.org (journals.plos.org/plosbiology/... Evolution doesn’t happen in isolation. We show that competing fungi can rewire the evolutionary trajectory of colistin resistance in P. aeruginosa. Great teamwork with the Ernst lab

The unique architecture of umbrella toxins permits a two-tiered molecular bet-hedging strategy for interbacterial antagonism Umbrella toxin particles produced by Actinobacteria contain five spokes tipped with variable lectin domains. Here, Zhao et al. show that these lectins mediate species-specific binding to a previously unrecognized cell surface carbohydrate polymer and propose that the modular nature of umbrella particles enables bet hedging against unpredictable competitor encounters.

Now online! The unique architecture of umbrella toxins permits a two-tiered molecular bet-hedging strategy for interbacterial antagonism

A tremendous story about a defense system that triggers plasmolysis! It was an incredibly exciting puzzle to crack. Huge thanks to @fnobrega.bsky.social for the opportunity to work on this!

Flyer for ASM DC Branch Meeting April 10th at Howard University

Attn DC area microbiologists, please join us for @asmdcbranch.bsky.social Spring Meeting on Fri, Apr 10th from 10-4 at Howard University. Keynote by Dr. Kumaran Ramamurthi. If interested in giving a short or lightning talk, submit abstracts by Mar 25: www.washingtondcasm.org/2026-spring-...

Cell death is a fundamental mechanism of antiviral immunity across diverse organisms, including bacteria. As my final PhD project with @jbdsf.bsky.social, I was curious whether cell death is required for successful immunity with the ancient cGAS pathway known as ‘CBASS.’

Spoiler – the answer is no!

CBASS limits bacteriophage production while maintaining cell viability in Pseudomonas aeruginosa https://www.biorxiv.org/content/10.64898/2026.02.24.707611v1

Great seminar today by Dr. Fauci discussing the historical perspectives of mankind's interactions with emerging infectious diseases and the challenges we face ahead

Structural mechanism and inhibitor discovery for DhhP, a Borrelia burgdorferi cyclic di-AMP phosphodiesterase with an Fe/Mn bimetallic center Klima et al. report the crystal structure of DhhP, a cyclic di-AMP phosphodiesterase of Borrelia. The structure reveals atomic details of the heterobimetallic active site and the overall asymmetry of ...

🫳 For c-di-AMP aficionados: Structural mechanism and inhibitor discovery for DhhP, a Borrelia burgdorferi cyclic di-AMP phosphodiesterase with an Fe/Mn bimetallic center!

In

👇

Structure www.cell.com/structure/fu...

@structure

Kizzmekia S Corbett-Helaire | Harvard T.H. Chan School of Public Health

STEM Black History Fact 19/28

Dr. Kizzmekia Corbett co-designed the immunological blueprint for the Moderna COVID 19 vaccine, applying years of coronavirus and viral immunology research.

hsph.harvard.edu/profile/kizz...

Bacteria frozen in ancient underground ice cave found to be resistant against 10 modern antibiotics Bacteria lurk everywhere. However, it&rsquo;s only after researchers retrieve them from the most remote corners of the Earth that we can learn more about the risks and potentials they pose. When resea...

Bacteria frozen in ancient underground ice cave found to be resistant against 10 modern antibiotics | EurekAlert! www.eurekalert.org/news-release...

Colony morphogenesis regulates sporulation dynamics in bacterial biofilms
#Bacillussubtilis #colonybiofilm #radialexpansion

bioRxiv

www.biorxiv.org/content/10.6...

Voices: Medical research saved my daughter’s life. We must protect the funding that makes that research possible. “Scientists are seeking new treatments and cures for many diseases, common and rare,” writes Lateishia Curtis in an op-ed. “Talk to friends, neighbors and policymakers about medical research. The next...

Wonderful op-ed by a mother who explains how NIH-funded research at U of U Health saved her daughter's life.

"That research — and Briar’s life — demonstrate just how critical federal support is to scientists, doctors and, especially, the patients they help."
www.sltrib.com/opinion/comm...

Unveiling hidden variables in stressed bacteria

@cp-cellreports.bsky.social Review by @divyach.bsky.social and @maxencevincent.bsky.social

www.cell.com/cell-reports...

F.D.A. Refuses to Review Moderna Flu Vaccine

This is troubling for multiple reasons, but one big one is companies won’t want to invest in R&D and clinical trials if they don’t think they can get a fair regulatory review—which is at the end of a long and extremely expensive process.

www.nytimes.com/2026/02/10/h...

Starvation-independent alarmone production inhibits translation through GTP depletion:

www.biorxiv.org/content/10.6...

#subtiwiki (p)ppGpp

Black scientists’ contributions to research throughout history This Black History Month, we’re recognizing Black scientists’ contributions to science throughout history.

STEM Black History Fact 5/28

Dr. Ruth Ella Moore was the first Black scientist to earn a PhD in microbiology and conducted key research on tuberculosis when TB was a leading cause of death.

A line graph showing funding curves for all NIH projects awarded grants for fiscal years 2021-2026. The curve for fiscal year 2026 is lagging behind that for previous fiscal years substantially.

My weekly update on NIH funding.

This is for all projects.

The breakdown for competing and non-competing awards will follow.

1/4

The Pseudomonas aeruginosa PrrF sRNAs and PqsA promote biofilm formation at body temperature | Journal of Bacteriology Biofilm formation is a critical virulence trait for many microbial pathogens that confers tolerance to the host immune system and antimicrobials. Pseudomonas aeruginosa is an opportunistic pathogen that forms biofilms resulting in treatment failure. Iron is a known requirement for P. aeruginosa biofilm formation, yet the precise role of iron in biofilm physiology remains unclear. Here, we show that temperature alters the requirement for the PrrF small regulatory RNAs, key components of P. aeruginosa’s iron starvation response, for biofilm formation. Specifically, PrrF is required for the optimal formation of flow-cell biofilms at 37°C but not at 25°C, yet most flow-cell biofilm studies are conducted at 25°C. These results demonstrate a previously underappreciated role of temperature in P. aeruginosa biofilm physiology.

The Pseudomonas aeruginosa PrrF sRNAs and PqsA promote biofilm formation at body temperature

-in #JBacteriol

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

A quorum-sensing molecule from Pseudomonas aeruginosa induces defensive multicellularity in a coinfecting pathogen | PNAS Microorganisms commonly exist in polymicrobial communities, where they can respond to interspecies secreted molecules by altering behaviors and phy...

Cool stuff!

“A quorum-sensing molecule from Pseudomonas aeruginosa induces defensive multicellularity in a coinfecting pathogen”

#microsky

New lab preprint! Andrew Frando, Bobby Parsek, and Graham Roberts describe how components of the quinolone quorum sensing circuit of P. aeruginosa interact in competition with another Gram-negative bacterium, S. maltophilia -- it's a three-component AND logic gate.

www.biorxiv.org/content/10.6...

Aeromonas adhesins facilitate kin and non-kin attachment to enable T6SS-mediated antagonism in liquid https://www.biorxiv.org/content/10.64898/2026.01.27.701733v1

Phage-Mediated Iron Acquisition by Pseudomonas aeruginosa https://www.biorxiv.org/content/10.64898/2026.01.26.700923v1

A consortium of human commensals protects against middle ear colonization by otopathogens https://www.biorxiv.org/content/10.64898/2026.01.26.701666v1

A quorum-sensing molecule from Pseudomonas aeruginosa induces defensive multicellularity in a coinfecting pathogen | PNAS Microorganisms commonly exist in polymicrobial communities, where they can respond to interspecies secreted molecules by altering behaviors and phy...

A quorum-sensing molecule from Pseudomonas aeruginosa induces defensive multicellularity in a coinfecting pathogen

-in PNAS from @anukharelab.bsky.social

www.pnas.org/doi/10.1073/...

Here’s the deal with the FY26 NIH funding bill:

One line in the 1000+ pg bill = significantly less science.

The increase to ~40% of grants moving to MYF is estimated to result in a 35% decrease in the NUMBER of NIH grants funded annually—moving the paylines from 10% to around 4%.

THIS IS BAD.

ASM Mechanism Discovery Meeting - Last chance to submit your abstract. Share your science. Deadline: Jan.21, 2 p.m. ET.

Last chance to submit to the ASM Mechanism Discovery Meeting at #ASMicrobe 2026. Abstracts close Jan. 21 at 2 p.m. ET. Showcase foundational research uncovering the mechanisms that power microbial life. Submit now: asm.social/2LT

Dealing with ScienCV formatting Some tips for composing and making your new NIH biosketch not look like garbage

Been hearing some horrifying chatter about dealing with the new #NIH common form and #ScienCV system, so I put together a short video with some tricks for mitigating some of those pain points.

Hope it helps? 🧪

open.substack.com/pub/emptymod...

A graphic showing E. coli and T7 bacteriophage floating in space. Image credit: C. Chitboonthavisuk.

Phage-host interactions have a role shaping microbial ecosystems, but what happens in #microgravity? Experiments aboard the #ISS reveal distinct evolutionary adaptations in T7 bacteriophage & #Ecoli, revealing #phage variants effective against resistant pathogens @plosbiology.org 🧪 plos.io/3LtKOfs

@archaellum.bsky.social lab reveals how #cdiAMP and 4 RCK proteins shape osmotic stress responses in H. volcanii 🧬🦠. In highly halophilic #archaea, c-di-AMP coordinates ion balance and cell volume—mirroring bacterial strategies for environmental stress adaptation.

👉 buff.ly/ApWkCtg