In vivo characterization of S. aureus strains in the zebrafish embryo model of infection with reduced growth in human blood in vitro. (a) Survival curves of fish injected with wild-type S. aureus JE2 or with JE2-purA, JE2-purB, or JE2-pabA (1,500 CFU each). (b) Survival curves of fish injected with wild-type S. aureus SH1000 (SH) or with SH1000 purA, SH1000 purB, or SH1000 pabA (1,500 CFU each). (c to e) Growth of S. aureus mutants within embryos after injection with 1,500 CFU of SH1000 purA (c), SH1000 purB (d), or SH1000 pabA (e). Open circles, live embryos; filled circles, dead embryos. (f) Survival curves of pu.1 knockdown fish injected with wild-type S. aureus SH1000, SH1000 purA, SH1000 purB, or SH1000 pabA (1,500 CFU).