Harikumar Sampath, Krishna R Salin, Amara Yakupitiyage, Saengchan Senapin and Ha Thanh Dong
Supplementation of a combination of organic acids and essential oils (Aquavibra™) was evaluated for its effect during experimental infection of Vibrio Parahaemolyticus Isolate-XN89 that caused Acute Hepatopancreatic Necrosis Disease (VPAHPND) in white shrimp, Penaeus vannamei as compared to that of an antibiotic. Initially, the in vitro Minimum Bactericidal Concentration (MBC) and Minimum Biofilm Inhibitory Concentration (MBIC) of Aquavibra™ against VPAHPND isolate XN89 were determined to be 3.12 mg/ml -1.56 mg/ml and 2 mg/ml, respectively. Aquavibra™ exhibited efficient biofilm reduction (85%), which was comparable to that of chloramphenicol (88%). feeding period using a diet supplemented with 0.5% of Aquavibra™. The growth and FCR between the Aquavibra™ supplemented group, and the control were not significantly different (P>0.05) after the feeding period. The experimental challenge resulted in 83% mortality in the infected control group. Antibiotic supplementation in feed using Trimethoprim-Sulfamethoxazole (Bactrim®) resulted in significant improvement in survival (61.54%), while the Aquavibra™ group showed comparable survival rate (60%) at 120 h post-challenge. Histopathological analysis revealed hepatopancreatic tissues with normal tubule epithelia in the uninfected group and severe collapsed hepatopancreatic tubule epithelia in the infected control group. However, the histopathology of moribund shrimp from Aquavibra™ and antibiotic supplemented groups revealed a mix of normal and thin collapsed hepatopancreatic epithelia, indicating less bacterial colonization of pathogens in hepatopancreas. Results from the present study indicate that dietary supplementation of Aquavibra™ at 0.5% is promising against AHPND in white shrimp.
Published Date: 2022-10-25; Received Date: 2020-11-04
