ABSTRACT
Introduction .......................................................................................................... 11 Movement of CTns between Species of Human Colonic Bacteroides spp. ......... 14 Charting the Movement of Resistance Genes into Bacteroides spp. ................... 16 The Triclosan Quandry ........................................................................................ 16 The Ecology of the Future ................................................................................... 17 References ............................................................................................................ 18
The movement of antibiotic resistance genes, as opposed to the movement of resistant bacterial strains, has become an issue of interest in connection with clinical and agricultural antibiotic use patterns. Evidence to date suggests that extensive DNA transfer is occurring in natural settings, such as the human intestine. This transfer activity, especially transfers that cross genus lines, is probably being mediated mainly by conjugative transfer of plasmids and conjugative transposons. Natural transformation and phage transduction probably contribute mainly to transfers within species or groups of closely related species, but the extent of this contribution is not clear. A considerable amount of information is available about the mechanisms of resistance gene transfer. The goal of future work on resistance ecology will focus on new approaches to detecting gene transfer events in nature and incorporating this information into a framework that explains and predicts the effects of human antibiotic use patterns on resistance development.
