Tiffany Zarrella
@tiffzarrella.bsky.social
assistant professor at georgetown | polymicrobial interactions | bacterial physiology | science educator | views my own
www.zarrellalab.org
www.zarrellalab.org
Reposted by Tiffany Zarrella
#microsky #phagesky
Transposon mutagenesis of jumbo #phage using an anti-CRISPR factor as selectable marker
www.biorxiv.org/content/10.1...
Transposon mutagenesis of jumbo #phage using an anti-CRISPR factor as selectable marker
www.biorxiv.org/content/10.1...
Bacteriophage genome-wide transposon mutagenesis
Bacteriophages have genomes that span a wide size range, are densely packed with coding sequences, and frequently encode genes of unknown function. Classical forward genetics has defined essential gen...
www.biorxiv.org
November 25, 2025 at 8:07 AM
#microsky #phagesky
Transposon mutagenesis of jumbo #phage using an anti-CRISPR factor as selectable marker
www.biorxiv.org/content/10.1...
Transposon mutagenesis of jumbo #phage using an anti-CRISPR factor as selectable marker
www.biorxiv.org/content/10.1...
Reposted by Tiffany Zarrella
This week is World #AntimicrobialResistance Awareness week
To mark the occasion, Dr Scott-Dearing reflects on her @natcomms.nature.com paper published in January, noting the setbacks and progress made in tackling #AMR since
To mark the occasion, Dr Scott-Dearing reflects on her @natcomms.nature.com paper published in January, noting the setbacks and progress made in tackling #AMR since
World AMR Awareness Week call to action: Patient and public involvement and engagement to improve impact on antimicrobial resistance – the time to act is now
A step change is required in citizen awareness of the global AMR health crisis and, crucially, public involvement in tackling it. The global context presents new challenges but real-world examples show what is possible and an historic moment approaches, that we can leverage for positive action.
bit.ly
November 24, 2025 at 6:38 PM
This week is World #AntimicrobialResistance Awareness week
To mark the occasion, Dr Scott-Dearing reflects on her @natcomms.nature.com paper published in January, noting the setbacks and progress made in tackling #AMR since
To mark the occasion, Dr Scott-Dearing reflects on her @natcomms.nature.com paper published in January, noting the setbacks and progress made in tackling #AMR since
Reposted by Tiffany Zarrella
Hot off the press! Our latest paper led by @fernpizza.bsky.social, understanding how plasmids evolve inside cells. These small, self-replicating DNA circles live inside bacteria and carry antibiotic resistance genes, but also compete with one another to replicate. 1/
www.science.org/doi/10.1126/...
www.science.org/doi/10.1126/...
Intracellular competition shapes plasmid population dynamics
From populations of multicellular organisms to selfish genetic elements, conflicts between levels of biological organization are central to evolution. Plasmids are extrachromosomal, self-replicating g...
www.science.org
November 20, 2025 at 9:42 PM
Hot off the press! Our latest paper led by @fernpizza.bsky.social, understanding how plasmids evolve inside cells. These small, self-replicating DNA circles live inside bacteria and carry antibiotic resistance genes, but also compete with one another to replicate. 1/
www.science.org/doi/10.1126/...
www.science.org/doi/10.1126/...
Reposted by Tiffany Zarrella
Experimental phage evolution results in expanded host ranges against antibiotic resistant Klebsiella pneumoniae isolates
-in @natcomms.nature.com
www.nature.com/articles/s41...
-in @natcomms.nature.com
www.nature.com/articles/s41...
Experimental phage evolution results in expanded host ranges against antibiotic resistant Klebsiella pneumoniae isolates - Nature Communications
Ghatbale et al. adapted a co-evolutionary technique to develop Klebsiella pneumoniae phages to be highly active longitudinally against K. pneumoniae clinical isolates, including drug resistant isolate...
www.nature.com
November 20, 2025 at 11:23 AM
Experimental phage evolution results in expanded host ranges against antibiotic resistant Klebsiella pneumoniae isolates
-in @natcomms.nature.com
www.nature.com/articles/s41...
-in @natcomms.nature.com
www.nature.com/articles/s41...
Reposted by Tiffany Zarrella
Two unrelated Pseudomonas aeruginosa phages require the exopolysaccharide Psl for infection
NPJ Biofilms and Microbiomes from Courtney Reichhardt and @micheleleroux.bsky.social and colleagues
www.nature.com/articles/s41...
NPJ Biofilms and Microbiomes from Courtney Reichhardt and @micheleleroux.bsky.social and colleagues
www.nature.com/articles/s41...
Two unrelated Pseudomonas aeruginosa phages require the exopolysaccharide Psl for infection - npj Biofilms and Microbiomes
npj Biofilms and Microbiomes - Two unrelated Pseudomonas aeruginosa phages require the exopolysaccharide Psl for infection
www.nature.com
November 19, 2025 at 11:13 AM
Two unrelated Pseudomonas aeruginosa phages require the exopolysaccharide Psl for infection
NPJ Biofilms and Microbiomes from Courtney Reichhardt and @micheleleroux.bsky.social and colleagues
www.nature.com/articles/s41...
NPJ Biofilms and Microbiomes from Courtney Reichhardt and @micheleleroux.bsky.social and colleagues
www.nature.com/articles/s41...
Reposted by Tiffany Zarrella
Did you know that some fungi are CARNIVOROUS? There are lots of species that do this, but I think Arthrobotrys oligospora is especially bonkers. These fungi sense when their prey (nematodes) are nearby by eavesdropping on the chemical signals that the nematodes use to communicate with each other 🧪🪲🍄
The predation process of the nematode trapping fungus Arthrobotrys oligospora.
YouTube video by Fungal-Worm Lab IMB Academia Sinica
www.youtube.com
November 19, 2025 at 1:59 AM
Did you know that some fungi are CARNIVOROUS? There are lots of species that do this, but I think Arthrobotrys oligospora is especially bonkers. These fungi sense when their prey (nematodes) are nearby by eavesdropping on the chemical signals that the nematodes use to communicate with each other 🧪🪲🍄
Reposted by Tiffany Zarrella
Calling all rising juniors & seniors: Interested in biological or biomedical research? Applications for our ’26 Summer Undergraduate Research Experience Program are now open! Nine weeks, hands-on research, & mentorship from some of the nation’s top scientists — learn more: bit.ly/CechFellows
Summer Undergraduate Research Experience | HHMI
The Cech Fellows Program is a paid, nine-week summer research experience empowering the next generation of scientific leaders.
bit.ly
November 18, 2025 at 2:44 PM
Calling all rising juniors & seniors: Interested in biological or biomedical research? Applications for our ’26 Summer Undergraduate Research Experience Program are now open! Nine weeks, hands-on research, & mentorship from some of the nation’s top scientists — learn more: bit.ly/CechFellows
Reposted by Tiffany Zarrella
#NewResearch
A bile acid-bound structure of toxin TcdB revealed the mechanism of inhibition and guided the design of a synthetic bile acid that alleviated C. difficile infection in mice.
#MicroSky 🦠💊
www.nature.com/articles/s41...
A bile acid-bound structure of toxin TcdB revealed the mechanism of inhibition and guided the design of a synthetic bile acid that alleviated C. difficile infection in mice.
#MicroSky 🦠💊
www.nature.com/articles/s41...
Structure-guided design of a synthetic bile acid that inhibits Clostridioides difficile TcdB toxin - Nature Microbiology
A bile acid-bound structure of toxin TcdB revealed the mechanism of inhibition and guided the design of a synthetic bile acid that alleviated Clostridioides difficile infection in mice.
www.nature.com
November 18, 2025 at 2:07 PM
#NewResearch
A bile acid-bound structure of toxin TcdB revealed the mechanism of inhibition and guided the design of a synthetic bile acid that alleviated C. difficile infection in mice.
#MicroSky 🦠💊
www.nature.com/articles/s41...
A bile acid-bound structure of toxin TcdB revealed the mechanism of inhibition and guided the design of a synthetic bile acid that alleviated C. difficile infection in mice.
#MicroSky 🦠💊
www.nature.com/articles/s41...
Join the Micro PI Slack if you haven't already! Microbiologists unite 🔬
Microbiology professor, want to join a slack for microbiology professors, any career stage, diverse career types (pure teaching, med school, R1, community college, pure research fed PIs, ...)
Message me for an invite link if you are interested.
No imposter syndrome, if you are 1% micro, join!
Message me for an invite link if you are interested.
No imposter syndrome, if you are 1% micro, join!
November 13, 2025 at 8:40 PM
Join the Micro PI Slack if you haven't already! Microbiologists unite 🔬
Reposted by Tiffany Zarrella
Genome synthesis, assembly, and rebooting of therapeutically useful high G+C% mycobacteriophages.
DOI: 10.1073/pnas.2523871122
https://pubmed.ncbi.nlm.nih.gov/41213020/
DOI: 10.1073/pnas.2523871122
https://pubmed.ncbi.nlm.nih.gov/41213020/
Genome synthesis, assembly, and rebooting of therapeutically useful high G+C% mycobacteriophages - PubMed
Bacteriophages show therapeutic promise for treating bacterial pathogens including nontuberculous mycobacteria (NTM). A major impediment is the paucity of therapeutically useful phages and the great variation in the phage infection profiles, especially among <i><i>Mycobacterium</i> abscessus</i> cli …
pubmed.ncbi.nlm.nih.gov
November 12, 2025 at 3:35 PM
Genome synthesis, assembly, and rebooting of therapeutically useful high G+C% mycobacteriophages.
DOI: 10.1073/pnas.2523871122
https://pubmed.ncbi.nlm.nih.gov/41213020/
DOI: 10.1073/pnas.2523871122
https://pubmed.ncbi.nlm.nih.gov/41213020/
Reposted by Tiffany Zarrella
A Two-Component Regulatory System Mediates Quorum Sensing-Dependent Morphology and Motility Transitions in the Archaeon Haloferax volcanii https://www.biorxiv.org/content/10.1101/2025.11.10.687552v1
November 11, 2025 at 4:16 AM
A Two-Component Regulatory System Mediates Quorum Sensing-Dependent Morphology and Motility Transitions in the Archaeon Haloferax volcanii https://www.biorxiv.org/content/10.1101/2025.11.10.687552v1
Reposted by Tiffany Zarrella
Oh, I love this. A new species of sea anemone was discovered recently that parks itself on top of a hermit crab shell like a hat. It seems to feed partly off the crab's faeces, but it also excretes a hard shell that extends the crab's home. In return, it's carried around the seafloor like a king.
November 10, 2025 at 9:57 PM
Oh, I love this. A new species of sea anemone was discovered recently that parks itself on top of a hermit crab shell like a hat. It seems to feed partly off the crab's faeces, but it also excretes a hard shell that extends the crab's home. In return, it's carried around the seafloor like a king.
Reposted by Tiffany Zarrella
#ISMEJournal paper from Simon Heilbronner
Competitive fitness of Staphylococcus aureus against nasal commensals depends on biotin biosynthesis and acquisition
academic.oup.com/ismej/advanc...
Competitive fitness of Staphylococcus aureus against nasal commensals depends on biotin biosynthesis and acquisition
academic.oup.com/ismej/advanc...
Competitive fitness of Staphylococcus aureus against nasal commensals depends on biotin biosynthesis and acquisition
Abstract. The human nasal microbiome can serve as a reservoir for pathogens. In particular, the opportunistic pathogen Staphylococcus aureus can be a membe
academic.oup.com
November 6, 2025 at 8:38 AM
#ISMEJournal paper from Simon Heilbronner
Competitive fitness of Staphylococcus aureus against nasal commensals depends on biotin biosynthesis and acquisition
academic.oup.com/ismej/advanc...
Competitive fitness of Staphylococcus aureus against nasal commensals depends on biotin biosynthesis and acquisition
academic.oup.com/ismej/advanc...
Reposted by Tiffany Zarrella
M. smegmatis uses new types of biofilm to enclose a liquid core and expand outwards in a weird new way.
October 30, 2025 at 8:30 PM
M. smegmatis uses new types of biofilm to enclose a liquid core and expand outwards in a weird new way.
Reposted by Tiffany Zarrella
note, gliding is not comparable to sliding
the here described spreading is very similar to sliding (=spreading by growth and facilitating compounds, like polysaccharides), which was known for Salmonella - the authors are not fully correct stating that sliding always depends on surfactant
the here described spreading is very similar to sliding (=spreading by growth and facilitating compounds, like polysaccharides), which was known for Salmonella - the authors are not fully correct stating that sliding always depends on surfactant
November 4, 2025 at 2:42 PM
note, gliding is not comparable to sliding
the here described spreading is very similar to sliding (=spreading by growth and facilitating compounds, like polysaccharides), which was known for Salmonella - the authors are not fully correct stating that sliding always depends on surfactant
the here described spreading is very similar to sliding (=spreading by growth and facilitating compounds, like polysaccharides), which was known for Salmonella - the authors are not fully correct stating that sliding always depends on surfactant
Reposted by Tiffany Zarrella
Swashing: a propulsion-independent form of bacterial surface migration journals.asm.org/doi/full/10.... #jcampubs
November 4, 2025 at 2:14 PM
Reposted by Tiffany Zarrella
One transcript, two functions: the emerging roles of dual-function RNAs
microLIFE review by @lizmarialuke.bsky.social and Kai Papenfort at @uni-jena.de
academic.oup.com/microlife/ad...
microLIFE review by @lizmarialuke.bsky.social and Kai Papenfort at @uni-jena.de
academic.oup.com/microlife/ad...
One transcript, two functions: the emerging roles of dual-function RNAs
Abstract. Bacteria use small regulatory RNAs (sRNAs) and small proteins to change gene expression and modulate cellular processes in response to changing e
academic.oup.com
October 27, 2025 at 6:15 PM
One transcript, two functions: the emerging roles of dual-function RNAs
microLIFE review by @lizmarialuke.bsky.social and Kai Papenfort at @uni-jena.de
academic.oup.com/microlife/ad...
microLIFE review by @lizmarialuke.bsky.social and Kai Papenfort at @uni-jena.de
academic.oup.com/microlife/ad...
Reposted by Tiffany Zarrella
Come join us in Knoxville!
The Dept. of Microbiology 🧫🦠 at the University of Tennessee is hiring 2 Assistant Professors (tenure track, 9-month appt.).
Microbial Drivers of Chronic Disease: apply.interfolio.com/173153Quantitative Microbe-Plant-Environment Interactions: apply.interfolio.com/173345
The Dept. of Microbiology 🧫🦠 at the University of Tennessee is hiring 2 Assistant Professors (tenure track, 9-month appt.).
Microbial Drivers of Chronic Disease: apply.interfolio.com/173153Quantitative Microbe-Plant-Environment Interactions: apply.interfolio.com/173345
October 24, 2025 at 12:18 PM
Come join us in Knoxville!
The Dept. of Microbiology 🧫🦠 at the University of Tennessee is hiring 2 Assistant Professors (tenure track, 9-month appt.).
Microbial Drivers of Chronic Disease: apply.interfolio.com/173153Quantitative Microbe-Plant-Environment Interactions: apply.interfolio.com/173345
The Dept. of Microbiology 🧫🦠 at the University of Tennessee is hiring 2 Assistant Professors (tenure track, 9-month appt.).
Microbial Drivers of Chronic Disease: apply.interfolio.com/173153Quantitative Microbe-Plant-Environment Interactions: apply.interfolio.com/173345
Reposted by Tiffany Zarrella
Reposted by Tiffany Zarrella
Reposted by Tiffany Zarrella
Wow. Harvard nuking its PhD programs
- Science PhD admissions reduced by more than 75%
- Arts & Humanities reduced by about 60%
- Social Sciences by 50–70%
- History by 60%
- Biology by 75%
- The German department will lose all PhD seats
- Sociology from six PhD students to zero
- Science PhD admissions reduced by more than 75%
- Arts & Humanities reduced by about 60%
- Social Sciences by 50–70%
- History by 60%
- Biology by 75%
- The German department will lose all PhD seats
- Sociology from six PhD students to zero
Harvard FAS Cuts Ph.D. Seats By More Than Half Across Next Two Admissions Cycles | News | The Harvard Crimson
The Faculty of Arts and Sciences slashed the number of Ph.D. student admissions slots for the Science division by more than 75 percent and for the Arts & Humanities division by about 60 percent for th...
www.thecrimson.com
October 21, 2025 at 5:11 PM
Wow. Harvard nuking its PhD programs
- Science PhD admissions reduced by more than 75%
- Arts & Humanities reduced by about 60%
- Social Sciences by 50–70%
- History by 60%
- Biology by 75%
- The German department will lose all PhD seats
- Sociology from six PhD students to zero
- Science PhD admissions reduced by more than 75%
- Arts & Humanities reduced by about 60%
- Social Sciences by 50–70%
- History by 60%
- Biology by 75%
- The German department will lose all PhD seats
- Sociology from six PhD students to zero
Reposted by Tiffany Zarrella
De-DUFing the DUFs 🧩 @franznarberhaus.bsky.social lab uncovers how small DUF1127 proteins regulate #phosphate uptake by binding the sensor kinase PhoR. Their conserved role from Agrobacterium to E. coli highlights how even small DUFs can shape bacterial physiology 🦠
buff.ly/jJd9Eho
buff.ly/jJd9Eho
October 21, 2025 at 7:02 AM
De-DUFing the DUFs 🧩 @franznarberhaus.bsky.social lab uncovers how small DUF1127 proteins regulate #phosphate uptake by binding the sensor kinase PhoR. Their conserved role from Agrobacterium to E. coli highlights how even small DUFs can shape bacterial physiology 🦠
buff.ly/jJd9Eho
buff.ly/jJd9Eho
Reposted by Tiffany Zarrella
A choline-sensing regulator coordinates metabolic adaptation and pathogenesis in Pseudomonas aeruginosa pulmonary infections
-n Science Advances
www.science.org/doi/10.1126/...
-n Science Advances
www.science.org/doi/10.1126/...
A choline-sensing regulator coordinates metabolic adaptation and pathogenesis in Pseudomonas aeruginosa pulmonary infections
A neglected regulator drives Pseudomonas aeruginosa adaption and persistence during lung infections via choline metabolic switch.
www.science.org
October 18, 2025 at 2:34 PM
A choline-sensing regulator coordinates metabolic adaptation and pathogenesis in Pseudomonas aeruginosa pulmonary infections
-n Science Advances
www.science.org/doi/10.1126/...
-n Science Advances
www.science.org/doi/10.1126/...
Reposted by Tiffany Zarrella
Why Do Filamentous Actinomycetota Produce Such a Vast Array of Specialized Metabolites?
www.annualreviews.org/content/jour...
www.annualreviews.org/content/jour...
Why Do Filamentous Actinomycetota Produce Such a Vast Array of Specialized Metabolites?
Bacteria of the phylum Actinomycetota are extremely diverse: They inhabit niches ranging from soils and ocean sediments to the normal human microbiota, and they cause tuberculosis, one of the most pre...
www.annualreviews.org
October 17, 2025 at 7:40 AM
Why Do Filamentous Actinomycetota Produce Such a Vast Array of Specialized Metabolites?
www.annualreviews.org/content/jour...
www.annualreviews.org/content/jour...
Reposted by Tiffany Zarrella
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
🔗 Check out open positions: meirelleslab.org
October 15, 2025 at 9:56 PM
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
🔗 Check out open positions: meirelleslab.org