Agricultural antibiotic use is suspected to be a major contributor in introducing new antibiotic resistance genes (ARGs) to human pathogens. Many ARGs carried by environmental microorganisms are ancient and therefore the have existed before the antibiotic era. In farm environment, the bacteria originating from animal gut and the environmental bacteria meet and mix due to land application of manure. Therefore production animal farms are proposed as reactors where genetic material from environmental bacteria might transfer to human or animal associated bacteria with contribution of mobile genetic elements (MGEs), which can capture genetic material from the environment and transfer between bacterial species.
We are studying the resistome of large Finnish production animal farms where use of antibiotics is limited to treating infections and manure application is allowed only during growing season. We follow changes in the resistome of manure, soil and surface waters from the beginning of the growing season until the fodder harvesting time, so that our results reflect the effects Finnish of agricultural practices.