Solebo, O. | bioRxiv Science

bioRxiv2026

Systematic discovery of a topical bacterial consortium that targets Staphylococcus aureus to treat atopic dermatitis

Atopic dermatitis (AD) flares are frequently accompanied by Staphylococcus aureus overgrowth and activation of quorum sensing-regulated virulence pathways that amplify inflammation and barrier dysfunction. Because commensal members of the skin microbiome can inhibit S. aureus colonization and virulence, we hypothesized that a consortium sourced from healthy human skin could therapeutically target S. aureus and ameliorate AD. We curated 180 skin-derived bacterial strains and used kChip, an ultrahigh-throughput coculture platform, to profile S. aureus physiological response to over four million combinations consisting of two, three, or seven cocultured strains. This screening identified Ensemble No.2 (ENS-002), a three-strain consortium that strongly suppressed S. aureus growth and virulence in follow-up microtiter assays and a Reconstructed Human Epidermis S. aureus Activity (RHESA) model. ENS-002 is now undergoing development as a topical live biotherapeutic product (LBP) treatment for AD.

microbiology↗

bioRxiv2021

Plasmodium falciparum vacuolar pyrophosphatase 1 for ring stage development and its transition to trophozoite

The malaria parasite relies on anaerobic glycolysis for energy supply when growing inside RBCs as its mitochondrion does not produce ATP. The ring stage lasts [~] 22 hours and is traditionally thought to be metabolically quiescent. However, recent studies show that the ring stage is active for several energy-costly processes including gene transcription/translation, protein export, and movement inside the RBC. It has remained unclear if a low glycolytic flux can meet the energy demand of the ring stage. Here we show that the metabolic by-product, pyrophosphate, is a critical energy source for the development of the ring stage and its transition to the trophozoite stage. During early phases of the asexual development, the parasite utilizes Plasmodium falciparum vacuolar pyrophosphatase 1 (PfVP1), an ancient pyrophosphate-driven proton pump, to pump protons across the parasite plasma membrane to maintain the membrane potential and cytosolic pH. Conditional deletion of PfVP1 leads to delayed ring stage development and a complete blockage of the ring-to-trophozoite transition, which can be partially rescued by Arabidopsis thaliana vacuolar pyrophosphatase 1, but not by the soluble pyrophosphatase from Saccharomyces cerevisiae. Proton-pumping pyrophosphatases are absent in humans, which highlights the possibility of developing highly selective VP1 inhibitors against the malaria parasite.

microbiology↗