EVALUATION OF EFFECTIVENESS OF DISEASE PREVENTION BY USING HERBAL EXTRACTS AGAINST Vibrio alginolyticus AND Photobacterium damselae, ISOLATED FROM HAEMORRHAGIC DISEASED RABBITFISH IN EXPERIMENTAL CONDITIONS

Abstract

This study was aimed to evaluate the potential for disease prevention using some herbal extracts against the pathogens Vibrio alginolyticus and Photobacterium damselae causing hemorrhagic disease in cultured gold rabbitfish. Antibacterial activity agianst V. alginolyticus and P. damselae of five herbal extracts in water-based solvents consisting of Euphorbia thymifolia, Phyllanthus urinaria, Wedelia chinensis, Eclipta prostrata and Perilla frutescens indicated that E. thymifolia extract (ETE) exhibited the strongest effect, while Perilla frutescens showed no antibacterial activity. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of these herbal extracts ranged from 312 to 2,500 mg/L and from 625 to 5,000 mg/L, respectively. Supplementing the fish feed with ETE at a concentration of 1,250 mg/kg did not affect the fish's survival rate and reduced the mortality of fish challenged with V. alginolyticus or P. damselae.