Plasmid-mediated resistance to tellurite: expressed and cryptic.

The ability of some bacteria to grow in the presence of high concentrations of tellurium compounds has been recognized for almost 100 years. Since then, interest in this phenomenon has generated a slow but steady trickle of literature. In the past few years, the use of modern techniques in molecular biology has led to a dramatic increase in our understanding of the genetics of several bacterial determinants for resistance to tellurium compounds. These determinants are frequently found to be encoded by plasmids which carry multiple antibiotic resistance determinants. Our understanding of the biochemistry of these systems remains limited. In this article, the history of the study of bacterial resistance to tellurium compounds is briefly reviewed. This is followed by an analysis of the recent developments in the study of plasmid-mediated resistance determinants. Finally, preliminary investigations on the possible mechanisms of bacterial resistance to tellurium compounds are presented.