Fig. 1
Adult zebrafish immunized with membrane vesicles and subsequently challenged with Piscirickettsia salmonis. (A) Cumulative survival (%) of adult zebrafish immunized with 20 ?g of MVs isolated from LF-89 or injected with phosphate buffer before challenged with P. salmonis 1 × 108 CFU (n = 65). (B) Histological sections from non-infected fish (I-II), fish injected with phosphate buffer (III-IV) and fish immunized with MVs (V-VI) at 3 and 7 days' post challenge (dpc), 10× magnifications, hematoxylin and Periodic acid Schiff's staining. Int: intestines, L. liver, arrows indicate the formation of granuloma-like structures.