Objective:

To evaluate the immunogenic potential and in vivo relevance of recombinant TadZ as a protective antigen against Aeromonas hydrophila in channel catfish, highlighting its potential role in improving disease control strategies.

Key Findings:

• TadZ immunization significantly reduced mortality from 79.6% in non-immunized to 26.1% in immunized fish, achieving a relative percent survival of 67.2%.
• A significant reduction in bacterial load was observed in the liver of TadZ-vaccinated fish, indicating effective immune response.
• Elevated IgM titers against both recombinant TadZ and heat-killed antigens were detected post-immunization and challenge, confirming robust humoral immune activation.

Interpretation:

TadZ is an effective immunogenic component that induces specific antibody responses, contributing to protection against A. hydrophila infection in channel catfish.

Limitations:

• The study primarily focuses on one strain of A. hydrophila, limiting the generalizability of the findings to other strains.
• Long-term efficacy and potential side effects of TadZ vaccination were not assessed, which may impact its viability as a vaccine candidate.

Conclusion:

TadZ shows promise as a candidate antigen for vaccine development against motile Aeromonas septicemia in catfish, warranting further investigation to enhance disease control in aquaculture.