Characterization of a novel live attenuated Edwardsiella piscicida vaccine based on the overexpressed type III secretion system and systematic deletion of the associated effectors

摘要: Abstract Edwardsiella piscicida causes edwardsiellosis in a variety of fish species and leads to tremendous economic losses the global aquaculture industries. Thus, effective safe prevention control this bacterium are urgently needed combat related infections. Live attenuated vaccines (LAVs) effectively prevent infectious diseases. However, most existing E. LAVs based on deletion genes encoding translocon components type III secretion system (T3SS), core virulence system, which is prominent protective bacterial antigen with strongest immunogenicity. In study, we systematically deleted all 9 established T3SS effectors (aka 9Δ) rpoS gene alternative sigma factor, esrB repressor (10Δ), then overexpressed obtain recombinant strain 10Δ/esrBOE. The modified strains 10Δ 10Δ/esrBOE exhibited severe attenuation vivo colonization defects. Additionally, vaccination by intraperitoneal injection could significantly upregulate expression recognition (TLR5) adaptive immune response-related (MHC II) spleen/kidney turbot fish, it also enhanced hosts’ serum bactericidal capacity. Finally, led increased protection against challenge wild EIB202 fish. Collectively, these findings demonstrated that was novel LAV therefore potential strategy for construction pathogens.