Antibacterial Activities of Metabolites from Vitis rotundifolia (Muscadine) Roots against Fish Pathogenic Bacteria

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 to the pond-raised channel catfish Ictalurus punctatus industry. Certain management practices are used by catfish farmers to prevent large financial losses from these diseases such as the use of commercial antibiotics. 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 isolated. Among these isolated compounds, (+)-hopeaphenol (2) and (+)-vitisin A (3) were found to be the most active (bacteriostatic activity only) 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 which were approximately 25X less active than the drug control florfenicol. Efficacy testing of 2 and 3 is necessary to further evaluate the potential for these compounds to be used as antibacterial agents for managing columnaris disease.

The natural stilbenoid (–)-hopeaphenol inhibits cellular entry of SARS-CoV-2 USA-WA1/2020, B.1.1.7 and B.1.351 variants

“…(-)-Hopeaphenol, vatalbinoside A, vaticanol B, and related stilbenoids and their stereoisomers have been isolated from a variety of plant sources including Hopea, Vitis, Shorea, Anisoptera, and Vatica species, among others (29)(30)(31)(32)(33)(34)(35)(36)(37). These compounds have been reported to exhibit several in vitro properties including antiproliferative (32)(33)(37)(38), antibacterial (through inhibition of the type III secretion system of Gram-negative bacteria) (30,39), antifungal (40), anti-influenza and herpes simplex virus (41)(42), and anti-inflammatory (34,43) activities, among others.…”

Fatty Acids-Enriched Fractions of Hermetia illucens (Black Soldier Fly) Larvae Fat Can Combat MDR Pathogenic Fish Bacteria Aeromonas spp.

“…Emodin could eradicate the A. hydrophila at 2.5 mg/mL [83], while oleic acid inhibits both Gram-negative and -positive bacteria at a concentration of 0.5 mg/mL after 15 min treatment [77]. Notwithstanding, antibacterial substances from the metabolites of Vitis rotundifolia (Muscadine) roots [84] demonstrated MIC between 10 and more than 100 µg/mL against pathogenic fish bacteria and MIC 50 values fluctuated between 16.5 and 22 µg/mL, albeit they were only bacteriostatic. In the present study, AWME3 was the most effective as an antibacterial substance from BSFL fat and could eradicate and inhibit the pathogenic fish bacteria at a low dose.…”