Are Dogs Altering Microbial Communities and Contributing to Antibiotic Resistance in Urban Park Soil Bacteria?

Parks and other green spaces are important parts of the urban landscape, providing residents with valuable ecosystem services. Many urban residents visit parks or other types of green space with their dogs on a daily basis, and dog waste is a common problem in these areas. The environmental and health impacts of dogs' left-behind solid waste has been and continues to be studied. However, the impacts of dog urine have received essentially no close attention, and its effects in urban areas are not well understood. Dogs are required to be kept on leashes in public spaces in Finland, and most of their urine has been found to be concentrated along walking paths. Since dogs are commonly treated for infections and other illnesses, these same areas are likely receiving sporadic, low-level doses of antibiotics. This highly localized and chronic deposition of residual antibiotics in areas used for human recreation and leisure represents a uniquely urban phenomenon. In this study we have analysed soil DNA extracts from Helsinki and Lahti greenspaces using SmartChip qPCR Analysis. We found elevated numbers of ARG copies in areas impacted by dog urine versus control sites. Further analysis will be needed to determine the significance of this effect, but the results suggest that dogs are contributing to the development of antibiotic resistance urban park soil bacteria.