Year Established: 2013 Start Date: 2013-03-01 End Date: 2014-02-28
Total Federal Funds: $10,000 Total Non-Federal Funds: $20,000
Principal Investigators: Jean McLain, Channah Rock
Abstract: Antibiotics are released daily into the natural environment in treated recycled water and through application of municipal biosolids onto agricultural fields, leading to increasing concerns regarding their contribution to the presence and persistence of resistance in environmental microbes. This is of special concern in the state of Arizona, where applications of recycled water and biosolids to agricultural and riparian areas are increasing each year. While conducting a multi-year study examining the effects of long-term (20+ years) application of recycled municipal wastewater and biosolids on the development of antibiotic resistance in soils, an intriguing pattern emerged. Though no increase in antibiotic resistance in environmental bacteria has been observed to date, isolates at both locations show a marked decrease in multiple-antibiotic resistance in sites receiving long-term recycled water and biosolids application. We hypothesize that the long-term application of recycled water and biosolids has increased soil organic carbon reserves and this has, in turn, decreased bacterial competition for organic molecules and decreased the necessity for bacterial antibiotic production. The proposed study will examine this hypothesis in a laboratory setting. A detailed assessment of the potential for abatement of multiple-antibiotic resistance will may help to alleviate environmental and public health concerns regarding the use of recycled water and biosolids to augment water and soil carbon supplies in Arizona.