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New preprint! #MicroSky Led by @ayaiizuka.bsky.social & Maria Vittoria Mazzuoli, we ask what helps Staphylococcus aureus enter, survive inside and evade treatment in human monocytes. www.biorxiv.org/content/10.6...

biorxiv.orgStaphylococcus aureus Mnh1 cation–proton antiporter promotes phagocytic uptake and intracellular survival in human monocytesWhile Staphylococcus aureus is predominantly an extracellular human commensal, it can also exhibit an intracellular lifestyle that enables its persistence within diverse host cell types, including mon...

4/8/26, 10:03 am12 reposts23 likes

Jan-Willem Veening

@veeninglab.com

4 Aug

Why look inside cells? Although S. aureus is mainly extracellular, it can persist within monocytes and macrophages. We found that internalization markedly increased antibiotic survival, making the intracellular niche a potential reservoir for treatment failure.

Jan-Willem Veening

@veeninglab.com

4 Aug

To find the genes behind this lifestyle, we built a genome-wide CRISPRi-seq screen targeting 2,865 S. aureus genes in a THP-1 co-infection model, then compared intracellular and extracellular fitness. @veeninglab.com @vincentdebakker.bsky.social

Jan-Willem Veening

@veeninglab.com

4 Aug

The intracellular and extracellular fitness landscapes separated clearly. The screen recovered known virulence factors and uncovered new genes specifically needed inside phagocytes. Among them: mnhB, part of the Mnh1 cation–proton antiporter.

Jan-Willem Veening

@veeninglab.com

4 Aug

Knocking down mnhB reduced early phagocytic uptake and intracellular bacterial burden. Importantly, the phenotype held across three distinct S. aureus lineages. Excitingly, when mnhB was depleted, levofloxacin cleared intracellular bacteria more effectively.