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ARS Home » Southeast Area » Oxford, Mississippi » Natural Products Utilization Research » Research » Publications at this Location » Publication #299402

Research Project: Chemistry of Natural Products for Nutraceutical Use, Pest Management and Crop Development

Location: Natural Products Utilization Research

Title: Antibacterial activity of acylglucinol derivatives against Flavobacterium columnare

Author
item Meepagala, Kumudini
item Schrader, Kevin

Submitted to: Journal of Agricultural Chemistry and Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/27/2014
Publication Date: 8/1/2014
Citation: Meepagala, K.M., Schrader, K. 2014. Antibacterial activity of acylglucinol derivatives against Flavobacterium columnare. Journal of Agricultural Chemistry and Environment. 3:89-95.

Interpretive Summary: Columnaris disease is one of the most common bacterial diseases of pond-raised channel catfish in the southeastern United States of America. This disease is caused by a bacterium Flavobacterium columnare. Direct economic losses to catfish producers are likely millions of dollars annually from single or mixed infections involving this disease. As part of our continuing effort to discover environmentally friendly compounds for the control of columnaris disease, acyl derivatives of phloroglucinol were prepared and tested against this bacterium in our laboratory. As a result of our investigation, we were able to identify several compounds with activities similar to the currently used drug florfenicol.

Technical Abstract: Columnaris disease is one of the most common bacterial diseases of pond-raised channel catfish (Ictalurus punctatus) in the southeastern United States of America. The Gram-negative, rod-shaped bacterium Flavobacterium columnare is the cause of columnaris disease. Direct economic losses to catfish producers are likely millions of dollars annually from single or mixed infections involving F. columnare. As part of our continuing effort to discover environmentally benign compounds for the control of columnaris disease, acyl derivatives of phloroglucinol were synthesized and tested against F. columnare using a rapid bioassay. Among the analogs that were tested, diacyl analogs showed very high antibacterial activity against F. columnare in the laboratory bioassay. Diisovalaryl and diisobutyryl analogs were found to have the strongest activity against F. columnare (isolate ALM-00-173) based on 24-h 50% inhibition concentration (IC50) and minimum inhibition concentration (MIC). Diisovalaryl and diisobutyryl analogs had IC50 values 0.82 mg/L and 0.80 mg/L, respectively, whereas the drug control florfenicol had an IC50 value of 0.81 mg/L. Diisovalaryl and diisobutyryl analogs also had 24-h relative-to-drug-control IC50 values around 1.0 indicating activities similar to florfenicol which is included in medicated feed and is one current management approach for columnaris disease.