Immunogenization of heat-killed vaccine candidate from aeromonas hydrophila in catfish (Pangasius hypophthalamus) using strain of Banjar, South Kalimantan, Indonesia

Abstract

Aeromonas hydrophila often attacks cultured catfish and causes motile aeromonad septicemia (MAS) disease outbreak in South Kalimantan, Indonesia. Deaths from A.hydrophila attacks could reach 100% so that prevention needs to done through vaccination. This study aimed to examine the potential immunogenicity of 6 heat-killed A.hydrophila vaccine candidates, a strain of Banjar, South Kalimantan, Indonesia. A.hydrophila strains obtained from infected catfish in aquaculture ponds around the Banjar District, South Kalimantan, Indonesia. From 10 fish infected with MAS, obtained 14 isolates of bacteria, ie, 8 isolates (AGC-1, AGC-2, AGC-3, AGC-4, AGC-6, AKC-2, AKC-3, and AKC-5) of Sungai Batang village, and 6 isolates (AGC-8, AGC-9, AKC-7, AKC-8, AKC-9, AKC-10) from Cindai Alus village. AGC signifies Aeromonas isolated from the gills, and AKC means Aeromonas isolated from the kidney. The antigen that used as a candidate for the heat-killed A.hydrophila vaccine made by inactivation through a heating process at 100oC for 60 minutes. The results showed antigens from AGC-2 and AGC-8 strains had high immunogenicity because they could increase antibody titers compared to other strains and controls. The antibody titer in catfish, two weeks after booster vaccination, increased and showed the same value. The results of the cross-reaction assay showed that the antigens from the AGC-2 and AGC-8 strains were able to cross-react with strain AGC-1, AKC3, AKC-5, but unable to cross-react with AKC-7, so that AGC-2 and AGC-8 could be recommended as vaccine candidates for MAS disease in South Kalimantan, Indonesia.