The secreted fructose 1,6-bisphosphate aldolase as a broad spectrum vaccine candidate against pathogenic bacteria in aquaculture

• FBA could be located in non-cytoplasmic components of five aquatic pathogens.
• Recombinant FBA showed good protection and cross-protection against these pathogens.
• Specific antibody and bactericidal activity against these pathogens were found.
• Antigen FBA protein was effectively presented and the adaptive immune was aroused.
• FBA could be designed as a broad spectrum vaccine against pathogenic bacteria.

The development of aquaculture has been hampered by different aquatic pathogens that can cause edwardsiellosis, vibriosis, or other diseases. Therefore, developing a broad spectrum vaccine against different fish diseases is necessary. In this study, fructose 1,6-bisphosphate aldolase (FBA), a conserved enzyme in the glycolytic pathway, was demonstrated to be located in the non-cytoplasmic components of five aquatic pathogenic bacteria and exhibited remarkable protection and cross-protection against these pathogens in turbot and zebrafish. Further analysis revealed that sera sampled from vaccinated turbot had a high level of specific antibody and bactericidal activity against these pathogens. Meanwhile, the increased expressions of immune response-related genes associated with antigen recognition and presentation indicated that the adaptive immune response was effectively aroused. Taken together, our results suggest that FBA can be utilized as a broad-spectrum vaccine against various pathogenic bacteria of aquaculture in the future.