Antibiotic resistance from, and to the environment

Antibiotic resistance currently causes hundreds of thousands of deaths worldwide; it is a major and growing public health threat globally. The origins of many resistance genes in pathogenic bacteria can be traced down to the environment; while a staggering number of resistant bacteria and resistance genes, selected for by human activities, are released into the environment. The nature, quantities and fates of this bidirectional flux of organisms and genes are mostly unknown. In order to understand the evolution of resistance within clinical settings, and the impact of the release of resistant bacteria into the environment, it is crucial to assess these questions and to assemble an integrated view of the problem. This review aims at providing an update on related issues previously discussed elsewhere, and to contribute to the comprehensive understanding of the environment as a source, receptacle and reservoir of antibiotic resistance.