Mitigating acute hepatopancreatic necrosis disease in vannamei shrimp: Harnessing bacteriophages from hepatopancreas and mangrove litter for sustainable aquaculture

Penaeus vannamei, a key export commodity in Indonesia's aquaculture industry, faces
significant threats from acute hepatopancreatic necrosis disease (AHPND), primarily caused by Vibrio
parahaemolyticus. Bacteriophages present a promising biocontrol strategy due to their targeted
bactericidal properties and absence of adverse side effects. This study evaluates the efficacy of
bacteriophages isolated from shrimp hepatopancreas and mangrove litter in combating V.
parahaemolyticus infections in P. vannamei. The experimental design employed a completely randomized
design (CRD) with five treatments and four replications, including group 1 (control), group 2 (pathogen
exposed), group 3 (hepatopancreas-derived phages), group 4 (mangrove-derived phages), and group 5
(combined phage treatment). Purified bacteriophages demonstrated high plaque titers, with mangrove
derived phages reaching 24×10⁹ PFU mL-1. In vitro assays confirmed significant bacterial inhibition,
particularly at the 18-hour mark, with phages effectively lysing V. parahaemolyticus cells as evidenced
by scanning electron microscopy. In vivo, phage-treated shrimp exhibited a marked enhancement in
immune response, notably in phagocytic activity, coupled with improved survival rates relative to the
control. Although total hemocyte counts were unaffected by phage treatments, the observed increase in
phagocytosis underscores the potential of phage therapy as a viable approach to controlling V.
parahaemolyticus infections in shrimp aquaculture. These findings highlight the potential of
bacteriophage application as a sustainable intervention against bacterial pathogens in shrimp farming.