The efficacy of Aeromonas jandaei BmSL-02 vaccine to control Aeromoniasis disease on North African catfish (Clarias gariepinus (Burchell 1822))

Abstract

Aeromonas jandaei is a Gram-negative bacterium of the genus Aeromonas that causes aeromoniasis or motile Aeromonas septicemia (MAS) in North African catfish (Clarias gariepinus (Burchell 1822)). Vaccination can be chosen to prevent adverse effects due to attacks by pathogenic bacteria. The study aims to determine the Aeromonas jandaei BmSL-02 vaccine's efficacy in controlling MAS disease in North African catfish. The type of vaccine is a whole-cell vaccine and is an attenuated vaccine. The samples used were North African catfish measuring 17.35-18.95 cm in length, and weighing 29.80-44.60 g, obtained from aquaculture ponds in the Banyumas area, Central Java. The study used an experimental method with a completely randomized design (CRD), five treatments, and three replications. The treatments consisted of J1: intramuscular injection (i.m); J2: intraperitoneal injection (i.p); J3: oral; J4: immersion; 5: without vaccination (control). Vaccination injection was done by injecting the vaccine into the fish's body with a dose of 0.1 mL at a density of 108 CFU mL-1 . A feed-based vaccine was prepared by spraying a vaccine suspension with a density of 108 CFU mL-1 in 100 mL of sterile PBS into 100 g of feed coated with 10 mL of egg white. The vaccine formulation for immersion was 10 mL at a density of 108 CFU mL-1 mixed with 990 mL of PBS solution. Booster vaccination was carried out one week after using the same method, except oral administration was given for the first 10 days. Challenge tests were carried out in the third week by injecting 0.1 mL of A. jandaei suspension per fish with a 107 CFU mL-1 dose in all treatments. The main parameters of the study included antibody titer, survival rate, relative percent survival (RPS), mean time to death (MTD), and growth rate (weight and length gain of fish). Supporting parameters included water quality parameters, namely water temperature, pH, and dissolved O2 levels. The main parameter data were analyzed by analysis of variance (ANOVA) and Duncan multiple range test (DMRT) at a test level of 5%. Supporting parameter data were descriptively and quantitatively analyzed. The results showed that the A. jandaei BmSL-02 vaccine was significantly different (P<0.05) and could increase antibody titer, survival value, RPS value, MTD, and length gain of North African catfish. However, fish weight gain was not significantly different (P>0.05). Vaccination has no negative impact on the growth of North African catfish. A. jandaei vaccine can improve North African catfish’s immune system, survival, and RPS. A. jandaei vaccine is one of the potential vaccine products that can control aeromoniasis in North African catfish.