Vaccination strategies to protect goldfish Carassius auratus against Aeromonas hydrophila infection

Abstract

Ornamental goldfish Carassius auratus were treated with whole cell (WC), extracellular product (ECP), outer membrane protein (OMP) and biofilm (BF) vaccines developed from the virulent Aeromonas hydrophila (AHV1; GenBank HQ331525.1) with and without the immunoadjuvant Asparagus racemosus. On various days post-vaccination (dpv), the treated fish were challenged with virulent A. hydrophila. These fish were monitored for survival, growth, specific bacterial reduction, and biochemical, haematological and immunological parameters. C. auratus attained 100% mortality within 7 d in non-vaccinated groups, whereas the vaccines helped to significantly (p ≤ 0.001) increase survival after 25 and 50 dpv. The vaccines with immunoadjuvant (ECP 2 , OMP 2 and BF 2 treatments) helped to reduce the Aeromonas load after the challenge, and serum albumin, globulin and protein levels were significantly (p < 0.01) improved in the OMP 2 -and BF 2 -treated groups. Haemoglobin and red blood cell counts were also significantly improved (p < 0.05) in the vaccinated groups compared to the control group. Additionally, haemagglutination occurred at the 1:12 dilution level in the vaccine plus immunoadjuvant-treated groups. Supplementing the vaccines with immunoadjuvant helped to improve phagocytosis to 54.07%, serum bactericidal activity to 14.6% and the albumin:globulin ratio to 7.6% in BF 2 after 50 dpv. Its positive effect significantly (p < 0.05) increased in vaccinated groups compared to controls. Based on the results, especially with the OMP and BF vaccines, the immunoadjuvant A. racemosus helped to improve the efficiency of the vaccines. This approach will aid in the development of more efficient vaccines against bacterial infections affecting the aquaculture industry. KEY WORDS:Ornamental fish · Biofilm · Outer membrane protein · OMP · Herbal immunoadjuvants Resale or republication not permitted without written consent of the publisher

Comparative Study on Bacterial Outer Membrane Protein (BOMP) and Bacterial Outer Membrane Gene (BOMPG) Vaccination to Goldfish Carassius Auratus against Aeromonas Hydrophila

“…This higher antibody production level may be suppressed the growth of A. hydrophila load. The earlier report by Thangaviji et al [19,20] showed that the A. hydrophila OMP and biofilm vaccines with the herbal immunoadjuvant, Asparagus racemosus extracts helped to decrease the Aeromonas load of 1.1 × 102 and 0.5 × 102 cfu/g respectively in the muscles on the 50th day of vaccination.…”

“…Generally there is an increased serum biochemical parameters observed in immunized fishes with vaccines or immunostimulants. Vaccination of A. hydrophila ECP, OMP and biofilm with herbal immuno-adjuvant helped to increase the serum albumin and globulin levels in C. auratus [20]. The herbal immunostimulants obtained from plants such as Lonicera japonica and Ganoderma lucidum helped to increase the immunoglobulin level in Oreochromis niloticus against A. hydrophila challenge [21].…”

“…Thangaviji [20] found that, the serum of C. auratus immunized with outer membrane vaccines was agglutinated at the dilutions of 1: 12 level. A. racemosus has been used as a good adjuvant [27] and provides an efficient and sustained immunostimulation to improve the immunogenicity of weak or low dose of antigens.…”

Effect of using bivalent vaccines (Whole cell and Outer membrane protein) against the infections of Edwardsiella tarda and Pseudomonas fluorescens in Cirrhinus mrigala

“…The whole cell vaccine and outer membrane protein vaccine were prepared by the method of Thangaviji et al, (2013).…”

“…Booster dose helped to increase the efficacy (RPS) in vaccinated groups compared to prime or first dose. In the previous study ofThangaviji et al, 2013 the immuno adjuvant Asparagus racemosus was found to improve the activity of different types of Aeromonas hydrophila vaccines [WC, ECP, OMP, and BF] and also improved the immunological enhancement, RPS rate, and decrease the mortality rate in Carassius auratus…”