Date of Award


Document Type



Environmental and Forest Biology

Thesis Advisor

Christopher M. Whipps


The laboratory zebrafish, Danio rerio, is a model organism used in numerous area of biological research, and is also subject to its own diseases. A common disease in zebrafish is mycobacteriosis, caused by Mycobacterium species. Elimination of Mycobacterium spp. is crucial in both preserving research studies as well as preventing the spread of the zoonotic pathogens to humans. Because of the common practice of exchanging fish between facilities, as well as a lack of a standard protocol for disinfection, these infections have become commonplace. In order to investigate the efficacy of disinfectants, this study tested the germicidal effect of sodium hypochlorite, hydrogen peroxide, and iodine on Mycobacterium chelonae and Mycobacterium abscessus. Concentrations of 100 ppm and 150 ppm sodium hypochlorite (from bleach),1.5% and 3% hydrogen peroxide, and 100 ppm iodine were tested. Statistically significant decreases in growth were observed in the treatments of M. abscessus with hydrogen peroxide, sodium hypochlorite, and iodine and M. chelonae with hydrogen peroxide and iodine. When treated with 1.5% hydrogen peroxide, M. abscessus showed a 14-­‐fold germicidal effect and M. chelonae showed a 6–fold germicidal effect when treated with 3% hydrogen peroxide. When treated with 150 ppm sodium hypochlorite, M. abscessus showed an 11–fold germicidal effect. When treated with 100 ppm iodine, both M. chelonae and M. abscessus were completely eliminated. Therefore, the current protocol for the application of bleach to zebrafish eggs cannot be relied upon for complete disinfection of mycobacteria, but the use of iodine shows promise as the basis for a new method.