Mode of action of the antimicrobial compound 5-bromo-5-nitro-1,3-dioxane (bronidox)

The mode of action of the antimicrobial agent, 5-bromo-5-nitro-1,3-dioxane (bronidox), was studied in detail for gram-positive and gram-negative bacteria, yeast and fungi. The studies included MIC testing, thiol inhibition of activity, intracellular leakage, oxygen consumption, incorporation of 3H-uridine, scanning electron microscopy, inhibition of Enzyme activity (papain) and in vitro oxidation of thiols to disulfides. It appears that the primary mode of action of bronidox is the same as, or similar to, that of bronopol, i.e. the oxidation of essential protein thiol causing inhibition of Enzyme activity and subsequent inhibition of microbial growth.