Microbial resistance : antibiotics interfere with metals

Dr Kristian K. Brandt, from Copenhagen University (Denmark), reviewed bacterial resistance in the animal-soil-human chain. The question was : Do metals used as feed additives contribute to dissemination of antibiotic resistance? Antibiotic resistance genes (ARG) can be found everywhere, even in location far from antibiotic use. Selection for Cu and Zn resistance is likely to happen, but co-selection for antibiotic resistance has been difficult to establish. The simultaneous use of both metals and antibiotics constitute a risk for selection of bacteria carrying genes conferring resistance to both metals and antibiotics. In most cases, Cu and Zn levels in manure amended soils will probably not be high enough to cause co-selection of ARGs. It is likely to occur when Cu concentration in soils will reach critical levels, like in vineyards due to the usage of Cu based fungicides.