Oil-Adjuvanted Polyvalent Formalin-killed Aeromonas hydrophila Vaccine Enhances Agglutinating Antibodies, Respiratory Burst, and Survival in Giant Gourami

Rozi (Doctoral Program of Veterinary Science, Faculty of Veterinary Medicine, Universitas Airlangga, Surabaya 60115, Indonesia )
Wiwiek Tyasningsih (Division of Microbiology, Faculty of Veterinary Medicine, Airlangga University, Surabaya 60115, Indonesia)
Jola Rahmahani (Division of Microbiology, Faculty of Veterinary Medicine, Airlangga University, Surabaya 60115, Indonesia)
Eduardus Bimo Aksono (Division of Microbiology, Faculty of Veterinary Medicine, Airlangga University, Surabaya 60115, Indonesia)
Muchammad Yunus (Division of Microbiology, Faculty of Veterinary Medicine, Airlangga University, Surabaya 60115, Indonesia)
Mohammad Anam Al-Arif (Division of Farm, Faculty of Veterinary Medicine, Airlangga University, Surabaya 60115, Indonesia)
Suryo Kuncorojakti (Division of Veterinary Anatomy, Faculty of Veterinary Medicine, Airlangga University 60115, Surabaya, Indonesia)
Daruti Dinda Nindarwi (Department of Aquaculture, Faculty of Fisheries and Marine, Airlangga University, Surabaya 60115, Indonesia)
Putri Desi Wulan Sari (Department of Aquaculture, Faculty of Fisheries and Marine, Airlangga University, Surabaya 60115, Indonesia)
Nina Nurmalia Dewi (Department of Aquaculture, Faculty of Fisheries and Marine, Airlangga University, Surabaya 60115, Indonesia)
Woro Hastuti Satyantini (Department of Aquaculture, Faculty of Fisheries and Marine, Airlangga University, Surabaya 60115, Indonesia)
Muhammad Browijoyo Santanumurti (Department of Aquaculture, Faculty of Fisheries and Marine, Airlangga University, Surabaya 60115, Indonesia)
Dita Wisudyawati (Department of Aquaculture, Faculty of Fisheries and Marine, Airlangga University, Surabaya 60115, Indonesia)
Mohammad Noor Amal Azmai (Department of Biology, Faculty of Science, Universiti Putra Malaysia, Serdang, Malaysia)
Annas Salleh (Department of Veterinary Laboratory Diagnosis, Faculty of Veterinary Medicine, Universiti Putra Malaysia, Serdang, Malaysia)
Gazali Salim (Study Program of Aquatic Resources Management, Faculty of Fisheries and Marine Science, Universitas Borneo Tarakan)
Suwarno Suwarno (Division of Microbiology, Faculty of Veterinary Medicine, Airlangga University, Surabaya 60115, Indonesia)

Journal of Fisheries & Marine
Vol. 18 No. 1 (2026): JURNAL ILMIAH PERIKANAN DAN KELAUTAN

Graphical Abstract  Highlight Research Adjuvanted polyvalent FKC elicited the strongest and most sustained multi-arm immune response in Osphronemus goramy compared with monovalent and non-adjuvanted vaccines. The lead formulation combined high agglutinating antibody titres with enhanced NBT respiratory burst, indicating synergistic humoral–innate activation against Aeromonas hydrophila. Polyvalent vaccines did not dilute immunogenicity; instead, strain combination plus adjuvant broadened and amplified immune responsiveness. Longitudinal profiling of il-1β and ifn-γ revealed a stable pro-inflammatory/Th1-like cytokine signature uniquely associated with the adjuvanted polyvalent FKC. The integrated immunological “fingerprint” supports the adjuvanted polyvalent FKC as a rational lead candidate for motile Aeromonas septicaemia control in warm-water gourami aquaculture.   Abstract Motile Aeromonas septicaemia (MAS), predominantly associated with Aeromonas hydrophila, remains a major constraint in giant gourami (Osphronemus goramy) aquaculture. This study evaluated formalin-inactivated A. hydrophila vaccines prepared from MAS-associated field isolates, comparing a monovalent formulation (P2), a non-adjuvanted polyvalent formulation (P3), and an oil-adjuvanted polyvalent formulation (P4) against PBS controls (P1). A total of 240 fish were used (60 per treatment) and assigned to two parallel cohorts (immunology and survival/challenge). Immune endpoints (agglutinating titres, NBT activity, and splenic il-1β and ifn-γ transcription) were assessed on days 7, 14, 21, 35, and 42 post-vaccination. The survival cohort was challenged intraperitoneally at day 21 with a homologous A. hydrophila strain and monitored for 14 days post-challenge. Vaccination was clinically well tolerated and improved survival relative to controls, with P4 showing the highest protection (RPS 81.8%). Agglutinating titres differed by treatment and time; at the peak sampling point (day 35), mean titres in P4 were ~200-fold higher than in P1, and model contrasts indicated significant differences versus controls (p<0.001). Splenic il-1β and ifn-γ transcript levels were higher in vaccinated groups than in controls at later time points. These findings support further evaluation of an oil-adjuvanted polyvalent inactivated A. hydrophila vaccine for gourami, including dose optimisation, extended safety assessment, heterologous challenge, and field validation.