Interaction of bacteria with mercuric compounds

We investigated the interaction of mercuric compounds with the bacteria Cor ynebacterium ammoniagenes, Micrococcus luteus, and Mycobacterium smegmatus capable of producing hydroxylamines (R-NOH) and 2-C-methyl-D-erythritol-2,4 -cyclopyrophosphate (MECP), which are prone to form free radicals. The inte raction of these substances with Hg2+ ions and their dynamics during the me rcuric poisoning of bacteria was studied by EPR and NMR. Under stress condi tions induced by lowering pH or generation of active oxygen species, the ba cteria and, especially, their mutants with enhanced sensitivity to oxidativ e stress, were found to respond to exposure to 1-3 mug/ml HgCl2 and p-chlor omercuribenzoate by a several-fold increase in their viability. The data ob tained were interpreted in terms of the involvement of the sulfhydryl group s of bacterial surface proteins in this phenomenon. The interaction of bact eria with mercuric compounds may affect the pathogenesis of tuberculosis an d other diseases.