Staphylococcus aureus delta toxin modulates both extracellular membrane vesicle biogenesis and amyloid formation

Extracellular membrane vesicles (MVs) produced by in planktonic cultures encapsulate a diverse cargo of bacterial proteins, nucleic acids, and glycopolymers that are protected from destruction by external factors. δ-toxin, a member of the phenol soluble modulin family, was shown to be critical for MV biogenesis. Amyloid fibrils co-purified with MVs generated by virulent, community-acquired strains, and fibril formation was dependent on expression of the δ-toxin gene ( ). Mass spectrometry data confirmed that the amyloid fibrils were comprised of δ-toxin. Although MVs were produced in a localized murine infection model, amyloid fibrils were not observed in the setting. Our findings provide critical insights into staphylococcal factors involved in MV biogenesis and amyloid formation.