Antibacterial activities of metabolites from Vitis rotundifolia (Muscadine) roots against fish pathogenic bacteria

Authors: Schrader, Kevin; IBRAHIM, MOHAMED - University Of Mississippi; ABD-ALLA, HOWAIDA - National Research Centre; Cantrell, Charles; PASCO, DAVID - University Of Mississippi

Submitted to: Molecules
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/22/2018
Publication Date: 10/25/2018
Citation: Schrader, K., Ibrahim, M.A., Abd-Alla, H.I., Cantrell, C.L., Pasco, D.S. 2018. Antibacterial activities of metabolites from Vitis rotundifolia (Muscadine) roots against fish pathogenic bacteria. Molecules. 23:2761-2768. https://doi:10.3390/molecules23112761.
DOI: https://doi.org/10.3390/molecules23112761

Interpretive Summary: Several types of aquatic bacteria can cause diseases in pond-raised channel catfish and cause large economic losses to farmers in the southeastern United States. Extracts from the roots of muscadine were found to inhibit the growth of certain disease-causing bacteria. Two compounds isolated from the root extracts of muscadine were subsequently discovered to possess antibacterial activity against the type of bacteria that causes columnaris disease in pond-raised channel catfish. These compounds may eventually be useful as antibacterial agents for managing outbreaks of columnaris disease.

Technical Abstract: Enteric septicemia of catfish, columnaris disease, and streptococcosis, caused by Edwardsiella ictaluri, Flavobacterium columnare, and Streptococcus iniae, respectively, are the most common bacterial diseases of economic significance for the pond-raised channel catfish Ictalurus punctatus industry. Several management practices are used by catfish farmers to prevent large financial losses from these diseases such as the use of commercial antibiotics and other chemicals. In order to discover environmentally benign alternatives, using a rapid bioassay, we evaluated a crude extract from the roots of muscadine Vitis rotundifolia against these fish pathogenic bacteria and determined that the extract was most active against F. columnare. Subsequently, several isolated compounds from the root extract were further evaluated against F. columnare. Among these isolated compounds, (+)-hopeaphenol and (+)-vitisin A were found to be the most active against F. columnare, with 24-h 50% inhibition concentrations of 4.0±0.7 and 7.7±0.6 mg/L, respectively, and minimum inhibitory concentrations of 9.1±0 mg/L for each compound. Efficacy testing of (+)-hopeaphenol and (+)-vitisin A is necessary to further evaluate the potential for these compounds to be used as antibacterial agents for managing columnaris disease.