A Sydney Rock Oyster Hymolymph are Shows Antimicrobial Properties to Mitigate Bacterial Infections

Abstract

The Sydney rock oyster (Saccostrea glomerata) is a native bivalve mollusk found in estuarine and coastal waters of Australia and holds significant ecological and commercial importance. As a filter-feeder, it is constantly exposed to microbial pathogens and relies on its innate immune system for protection. A major component of this defense is the haemolymph, which contains antimicrobial proteins and peptides. Recent studies have shown that haemolymph exhibits antibacterial activity against a range of Gram-positive and Gram-negative bacteria, inhibits biofilm formation, and can enhance the effectiveness of conventional antibiotics. These properties highlight its potential as a natural source of novel antimicrobial agents. However, Sydney rock oysters are susceptible to diseases such as juvenile oyster disease (JOD), QX disease caused by Marteilia sydneyi, and herpesvirus infections, which threaten aquaculture productivity. Understanding haemolymph’s antimicrobial properties offers potential strategies to mitigate bacterial infections and improve oyster health management.