Using kaolin clay to combat columnaris disease

Authors: Beck, Benjamin; Webster, Carl

Submitted to: Arkansas Aquafarming
Publication Type: Popular Publication
Publication Acceptance Date: 5/5/2015
Publication Date: 10/1/2015
Citation: Beck, B.H., Webster, C.D. 2015. Using kaolin clay to combat columnaris disease. Arkansas Aquafarming. 32:(2)1-8.

Interpretive Summary:

Technical Abstract: Columnaris disease, caused by the bacterial pathogen Flavobacterium columnare, continues to be a major problem in cultured freshwater finfish. Despite the far-reaching negative impacts of columnaris disease, safe and effective preventatives and curatives for this disease remain limited. In the present study, we evaluated the potential of kaolin, a type of clay, for the prevention of columnaris disease. Channel catfish fingerlings were experimentally challenged with F. columnare in untreated water or with water containing kaolin (0.13 ounces/gallon of water). Over the 7 day course of study, kaolin treatment led to significantly improved survival (96%) as compared to untreated fish (78% survival). Microscopic examination of the gills revealed that kaolin-treated fish had substantially less gill damage than untreated controls. Analysis of gill tissue revealed that kaolin significantly reduced F. columnare adhesion. Incubation of kaolin with F. columnare showed that kaolin reduced the number of F. columnare in culture suspensions by strongly binding to the bacteria. In summary, kaolin can improve survival, reduce gill lesions, and prevent bacterial attachment to key tissues associated with columnaris disease in channel catfish by binding to F. columnare.