Malcolm White

Malcolm White

@mfwhite2.bsky.social

Molecular microbiologist at the University of St Andrews, Scotland. My scientific interests include: CRISPR, antiviral defence, cyclic nucleotide signalling, archaea, nucleases.

1.1K followers213 following174 posts

Malcolm White reposted

hobbslabmicro.bsky.social
@hobbslabmicro.bsky.social

Funded 4-year PhD studentship alert! 📣 "Efficacy & Mechanisms of Novel Treatments for Antibiotic-Tolerant Infections" shorturl.at/ruD0t Come join our vibrant and supportive group in St Andrews and undertake an industry placement @amprologix.bsky.social with @matupton.bsky.social. Please share!

findaphd.comEastbio: Efficacy and Mechanisms of Novel Treatments for Antibiotic-Tolerant Infections at University of St Andrews on FindAPhD.comPhD Project - Eastbio: Efficacy and Mechanisms of Novel Treatments for Antibiotic-Tolerant Infections at University of St Andrews, listed on FindAPhD.com

Malcolm White reposted

Tominaga K. (tomiken)
@pacyc184.bsky.social

Loss of restriction-modification methyltransferases drives persistence to fluoroquinolones in Pseudomonas aeruginosa | bioRxiv

biorxiv.orgLoss of restriction-modification methyltransferases drives persistence to fluoroquinolones in Pseudomonas aeruginosaThe resurgence of phage therapy has renewed interest in the interplay between phage resistance and antibiotic susceptibility and has stimulated research in the emergent field of non-canonical cellular functions carried out by defence systems. Yet it remains largely unknown whether intracellular antiphage defence systems influence bacterial physiology, resistance or persistence to antibiotics. Here we discovered that besides its canonical antiphage defence function, the type I restriction modification (RM) system profoundly affects the physiology of the opportunistic pathogen Pseudomonas aeruginosa. Deletion of the type I RM methyltransferase HsdM reduces the size of the bacterial nucleoid and delays DNA replication initiation and exit from lag phase in P. aeruginosa PAO1. Crucially, P. aeruginosa strains isolated from patients with cystic fibrosis (CF) and lacking the RM type I system also display slower growth compared to strains isolated from other sites of infections and encoding this system. Deletion of HsdM selectively increases the levels of persisters that survive treatment with fluoroquinolones by displaying enhanced SOS response but without acquiring resistance. Importantly, we measured elevated persistence to fluoroquinolones also in P. aeruginosa CF isolates lacking the type I RM system, providing a functional link between RM systems, slow growth and persistence to fluoroquinolones. Together these findings open a new way of approaching bacterial susceptibility to antibiotics, bringing antiphage defence systems in a forward-facing position in this field. ### Competing Interest Statement The authors have declared no competing interest. Biotechnology and Biological Sciences Research Council, BB/V008021/1, BB/X003051/1 Engineering and Physical Sciences Research Council, EP/Y023528/1 Medical Research Council, MR/Y033892/1 Novo Nordisk Foundation, NNF 18OC0033946 Deutsche Forschungsgemeinschaft, 390874280

Malcolm White reposted

Nature Microbiology
@natmicrobiol.nature.com

Out Now! Systematic mapping of bacteriophage gene essentiality with HIDEN-SEQ #MicroSky

go.nature.comSystematic mapping of bacteriophage gene essentiality with HIDEN-SEQNature Microbiology, Published online: 25 September 2026; doi:10.1038/s41564-026-02455-8HIDEN-SEQ (hidden Acr-enabled transposon-insertion sequencing) is a transposon-insertion sequencing method for phages that systematically links their genes to selectable phenotypes.

Malcolm White reposted

Anna Olina
@annaolina.bsky.social

Excited to share this part of my research as a part of @multidefence.bsky.social: meet viPAO1 - the very best Pseudomonas strain for phage research😉 Also check out our temperate phage collection featuring PAnicatthedisco, PAthetic and some other new fun names🎉 www.biorxiv.org/content/10.6...

biorxiv.orgEngineering the Pseudomonas aeruginosa virus-isolation host viPAO1 reveals how host genetic barriers shape recoverable phage diversityCultured phage collections provide essential access to viral biology, but they capture only a small and biased fraction of natural phage diversity. Key barriers to diverse phage isolation are likely t...

Malcolm White reposted

Biochemical Society
@biochemsoc.bsky.social

Looking to submit your work to a themed collection? We have collections open in The Prokaryotic Immune System, Shifting Paradigms in Immunity: New Cells, or New Functions for Old Cells and more! Visit our website to discover our open collections and submit your best work: https://ow.ly/YauR50ZOR0G 🧪

Malcolm White reposted

James Connolly
@ruamicro.bsky.social

Are you a motivated researcher interested in bacteria-host interactions? We have postdoc position available in my lab to join our Wellcome Trust funded collaborative team. We will study the role and regulation of the enigmatic sphingolipids in E. coli. Please share. www.jobs.ac.uk/job/DSX115/r...

jobs.ac.ukResearch Assistant/ Associate in Bacteria-Host Interactions at Newcastle UniversityExplore an exciting academic career as a Research Assistant/ Associate in Bacteria-Host Interactions. Don't miss out on other academic jobs. Click to apply and explore more opportunities.

Malcolm White reposted

Ellinor Alseth
@ellinoralseth.bsky.social

What a Friday, finally seeing this published in @cp-trendsmicrobiol.bsky.social! We hope this will be of interest to anyone working in the bacterial immune system field (or microbiology in general), and who wants an evolutionary take on it 🦠🧫 Open Access link: authors.elsevier.com/a/1nllx,L%7E...

Ellinor Alseth@ellinoralseth.bsky.social

When is an antiphage mechanism an evolved defence adaptation? This question has been on my mind for so long, because despite the field’s rapid progress there is currently no widely agreed framework in place to answer it. So @brownlab.bsky.social and I wrote this, and I'm happy to share the preprint!

ecoevorxiv.orgThe bacterial immune system: identifying evolved defense adaptations
Malcolm White
@mfwhite2.bsky.social

Change is afoot

UK Research and Innovation@ukri.org

Today, we’re updating our grant assessment approach to speed up grant decisions, respond to the challenges and opportunities presented by generative AI, and ensure we continue to back the best talent and ideas. Read the full update: www.ukri.org/news/ukri-mo...

ukri.orgUKRI modernises grant assessment for the age of AIUKRI is updating its grant assessment approach to speed up grant decisions, respond to generative AI and ensure we continue backing the best talent and ideas.
Malcolm White
@mfwhite2.bsky.social

Most of you are too young to know this song, but it feels prescient right now. www.google.com/url?sa=t&sou...

google.comHazel O'Connor - Eighth Day HQHazel O'Connor - Eighth Day 1980 Check Out Hazel O'Connor - Eighth Day (Unknown Version - Video) https://www.youtube.com/watch?v=Pe9EYV6SJR8 Copyright Disclaimer: Under Section 107 of the Copyright Act 1976, allowance is made for "fair use" for purposes such as criticism, comment, news reporting, teaching, scholarship, and research. Fair use is a use permitted by copyright statute that might otherwise be infringing. Non-profit, educational or personal use tips the balance in favor of fair use.

Malcolm White reposted

Magnus Bauer
@kinasekid.bsky.social

AlphaFold Server’s ligand menu just got a lot bigger and I almost missed it! You can now add any ligand from the wwPDB Chemical Component Dictionary. Just enter its CCD code 🥳

Malcolm White reposted

Franklin Nobrega
@fnobrega.bsky.social

Replying to @fnobrega.bsky.social

Great work by shared first authors Arpita, Yi, and Maxwell Burroughs! www.biorxiv.org/content/10.6...

biorxiv.orgCyclase-generated 3',5'-cGMP activates PucsarTIR antiphage defense through a stepwise zig-zag aligned filament assemblyBacteria use nucleotide second messengers to couple phage recognition to antiviral effector activation. Here, we identify Pucsar, an ofshoot of the Pycsar-related antiphage family, whose cyclases gene...

Malcolm White reposted

Kranzusch Lab
@kranzuschlab.bsky.social

The shared principles of human and bacterial antiviral immunity An honor to highlight remarkable discoveries from many labs over the past 12 years that unite previously disparate fields of how animal cells and prokaryotes defend against viruses. www.nature.com/articles/s41... rdcu.be/fzwyB

nature.comShared principles of human and bacterial antiviral immunity - NatureThe Review describes shared ancient, conserved mechanisms between human antiviral immunity and bacterial anti-phage systems, outlining universal principles of pathogen sensing, signalling and effector...

Malcolm White reposted

Daria Van Tyne
@dariavantyne.bsky.social

Replying to @dariavantyne.bsky.social

And last but not least, a MiniReview about phage therapy co-authored by many of us @pghphageprogram.bsky.social was published today in mBio journals.asm.org/doi/10.1128/...

journals.asm.orgApproaching the post-antibiotic era: phage therapy current practices and future horizons | mBioPhages are the naturally occurring viruses of bacteria (see Table 1 for key definitions). They have co-evolved with their bacterial prey across billions of years, resulting in highly specific phage-ho...

Malcolm White reposted

Tominaga K. (tomiken)
@pacyc184.bsky.social

Phage hijacks host phosphorothioate DNA modification machinery to circumvent bacterial Ssp defences | Nature Microbiology

nature.comPhage hijacks host phosphorothioate DNA modification machinery to circumvent bacterial Ssp defences - Nature MicrobiologyThe phage-encoded protein PptA enables its DNA to masquerade as the host and evade cleavage, providing a potential foundation for engineering therapeutic phages that could bypass this widespread defence system.

Malcolm White reposted

Craig Kaplan
@triggerloop.bsky.social

Some bacteria use the CRISPR/Cas systems as transcriptional repressors of other anti-phage systems, such that when CRISPR interfered with, gene expression of repressed anti-phage systems goes up www.nature.com/articles/s41...

nature.comCRISPR–Cas regulates expression of embedded anti-phage defence systems - NatureCRISPR–Cas systems transcriptionally tune diverse innate defences using CRISPR RNA-like guides to balance antiviral protection with fitness, and hyperactivate these defences when compromised, establis...

Malcolm White reposted

Jason Nomburg
@jnoms.bsky.social

Happy to share the first preprint out of the Nomburg lab! Many aspects of cellular immunity are shared across the tree of life. Here, we show that some of these conserved aspects of cellular immunity are mirrored by conserved effectors of immune antagonism. Thread below! 1/15

bioRxiv Microbiology@biorxiv-microbiol.bsky.social

Conserved folds enable immune antagonism across the tree of life https://www.biorxiv.org/content/10.64898/2026.07.21.739742v1

Malcolm White reposted

Rafael Pinilla-Redondo (Rafa)
@rafomics.bsky.social

1/4 Every good defence needs a backup! 🛡️⚔ Out now in @natrevmicro.nature.com our Comment on "𝗶𝗺𝗺𝘂𝗻𝗲 𝘀𝗮𝗳𝗲𝗴𝘂𝗮𝗿𝗱𝗶𝗻𝗴"! 🎉 🔗 www.nature.com/articles/s41...

nature.comImmune safeguarding as a conserved principle of antiviral defence - Nature Reviews MicrobiologyAll organisms defend against viral infections through active immunity mechanisms that clear the virus or population-level mechanisms that cause regulated cell death. Recent research increasingly shows...

Malcolm White reposted

Cell Host & Microbe
@cp-cellhostmicrobe.bsky.social

A family of lanthipeptides with anti-phage function Discovery of 2,000+ lanthipeptide biosynthetic gene clusters with anti-phage potential. Lanthivirins inhibit phage replication by targeting phage proteins & interfering with phage DNA replication. www.cell.com/cell-host-mi...

cell.comA family of lanthipeptides with anti-phage functionShomar, Guillaume, et al. report the genomics-driven discovery of a family of more than 2,000 lanthipeptide biosynthetic gene clusters with anti-phage potential. They experimentally demonstrate anti-p...

Malcolm White reposted

Nogales Lab
@nogaleslab.bsky.social

Thrilled to share our collab led by Grace Hibshman with the Shipman lab! Type IX retron-Kva2 structure reveals phage detection via an HTH fold, not a primary sequence. We computationally designed triggers that program bacteria cell death, pointing toward designer antimicrobials.

Malcolm White
@mfwhite2.bsky.social

Highly recommended

Alice Roberts@profaliceroberts.bsky.social

I can’t quite believe this news - my book Domination is the NUMBER ONE topselling history paperback of 2026 so far! A huge thank you to all my readers! And all the booksellers of course! www.thebookseller.com/bestsellers/...

Malcolm White reposted

Cell Host & Microbe
@cp-cellhostmicrobe.bsky.social

Missing link between prokaryotic immune systems Phylogenetic analysis of YprA (widespread helicases) reveals distinct class of defense systems-ARMADA-that connect DISARM & Druantia. ARMADA protects against diverse phages, synergizing w/Druantia III www.cell.com/cell-host-mi...

cell.comYprA-family helicases provide the missing link between diverse prokaryotic immune systemsYprA-family helicases represent a key hub in the prokaryotic defense network. Through phylogenetic analysis of YprA, Bell and colleagues identify a distinct class of defense systems, called ARMADA. AR...
Malcolm White
@mfwhite2.bsky.social

This is just a grumpy post from an old geezer - feel free to ignore. Pre-internet we had to do our own photography and post 3 copies of our papers to journals. The internet speeded everything up. 😀

Malcolm White
@mfwhite2.bsky.social

Now however, I seem to spend days jumping through hoops for sub-editors who adhere to strict algorithms, all subtly different for each publisher.🤨 I miss Letraset. Told you it was grumpy!