Antimicrobial activity of two natural products against grouper iridovirus and bacteria

• Main Authors: Kao, Tsung-Yu, 高宗佑
• Other Authors: Chou, Hsin-Yiu
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/g98fby

碩士 === 國立臺灣海洋大學 === 水產養殖學系 === 105 === Outbreaks of viral and bacterial diseases along with high mortalities have threatened the aquaculture for years. To date, disease problems still impact the development of industry continuously. In order to seek an eco-friendly disease prevention strategy, the use of dietary supplements derived from plants has accelerated in recent years. Herein, the antiviral activity and bactericidal effect of two natural products, Rhamnan sulphate from Green laver (Monostroma latissimum) and Oregano essential oil from Origanum vulgare against important fish pathogens will analyze respectively. Groupers (Family Serranidae) are viewed as one of the important maricultured fish species in Asia-Pacific region. Therefore, grouper will use as a model fish in this study. First, the cytotoxicity effect of these two products was determined on grouper kidney (GK) and grouper fin (GF-1) cells, and appropriate concentration range was selected for following experiments. Subsequently, the antiviral activity of RS and Oregano against grouper viruses was confirmed by MTT tests and inhibition of GIV replication. However, antibacterial effect against Streptococcus agalactiae, Streptococcus iniae, Vibrio brasiliensis and Vibrio parahaemolyticus varied of these two products. After challenged by GIV, the relative survival rate increased to 70% in groups with feeding natural products that indicated these two natural products show good antiviral effect on the grouper.