Zebrafish Infection Model for Staphylococcus aureus

Staphylococcus aureus SH1000 expressing mCherry (SH1000 pMV158-mCherry) [28 (link)] was cultured in brain heart infusion (BHI) broth medium (Sigma, 53286) at 37°C supplemented with tetracycline (Sigma, 87128) at 5 µg/ml. Zebrafish larvae at 30 hpf (hours post-fertilization) were microinjected into the circulation with bacteria as previously described [25 (link)]. Briefly, anesthetized larvae were embedded in 3% w/v methylcellulose (Sigma, M7027) and injected individually using microcapillary pipettes (WPI, TW100-4) filled with the bacterial suspension of known concentration. For macrophage depletion, clodronate liposomes (Liposoma BV) were injected at 26 hpf, as previously described [38 ]. Following infection, larvae were observed frequently up to 120 hpf, and numbers of dead embryos recorded at each time point.