SREL Reprint #2881

Inhibition of Growth for Select Gram-Negative Bacteria by Tricaine Methane Sulfonate (MS-222)

Luke A. Fedewa and Angela Lindell

University of Georgia, Savannah River Ecology Laboratory, Aiken, South Carolina, 29802 USA

Abstract: Tricaine methane sulfonate (MS-222 or Tricaine) is a commonly used agent for anesthesia
and euthanasia in aquatic organisms. Bacterial diseases are routinely discovered in captive aquatic vertebrates, and bacterial culture is often performed to identify potential pathogens. Currently, no study has evaluated the effect of MS-222 on bacterial isolation from the aquatic environment. Minimum inhibitory concentration tests using a gradient of MS-222 were performed for 11 species of Gram-negative bacteria isolated from aquatic environments. MS-222 inhibited the growth of all bacterial species at 5000 mg/L, while bacterial growth was depressed at MS-222 concentrations as low as 200 mg/L. Based on these findings, special care should be taken when interpreting the results of bacterial culture when MS-222 is used to anesthetize or euthanize fish or amphibians.

Keywords: tricaine methane sulfonate, bacteria, euthanasia, MS-222, minimum inhibitory concentration, anesthesia

SREL Reprint #2881

Fedewa, L. A. and A. H. Lindell. 2005. Inhibition of growth for select gram-negative bacteria by tricaine methane sulfonate (MS-222). Journal of Herpetological Medicine and Surgery 15:13-17.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).