25 research outputs found

    Assessing Fecal Contamination in Groundwater from the Tulum Region, Quintana Roo, Mexico

    Get PDF
    The Yucatan Peninsula’s groundwater is experiencing increases in degradation due to swelling population and tourism; yet little is known about sources and transport of contaminants in drinking water supplies. The karst allows for rapid transport of microbial and chemical contaminants to the subsurface, resulting in significantly increased potential for pollution of groundwater. The objective of this research is to determine the occurrence, source, and extent of fecal con- tamination in the Tulum region of the Peninsula. A multi-analytical approach was undertaken in impacted and unim- pacted groundwater locations; measurements included physicochemical parameters, total coliform and E. coli, Bacter- oides (human vs total) and caffeine. The results indicate a variation in geochemistry from impacted to protected sites. The total coliform and E. coli show fecal contamination is wide spread. However, the presence of human Bacteriodes and caffeine in the water in the Tulum well field indicates that the recent human activities next to the well field are im- pacting the drinking water supply. This project is an assessment of the area’s current water quality conditions and the probable impact that the aforementioned growth would have on the area’s water supply. By applying multiple source parameter measurements, including molecular microbiology and chemical indicators it was confirmed the extent of fe- cal contamination of human origin covered the entire sampling region.Funding for this research was provided by Northern Illinois University’s Center for Latino and Latin American Studies, the Geology and Environmental Geosciences de- partment, and Library. This work was also funded by the United States Department of Agriculture, Agricultural Re- search Service, Water Management Conservation and Re- search Program. This article is made openly accessible in part by an award from the Northern Illinois University Libraries’ Open Access Publishing Fund

    Antibiotics and antibiotic resistance in agroecosystems : State of the science

    Get PDF
    We propose a simple causal model depicting relationships involved in dissemination of antibiotics and antibiotic resistance in agroecosystems and potential effects on human health, functioning of natural ecosystems, and agricultural productivity. Available evidence for each causal link is briefly summarized, and key knowledge gaps are highlighted. A lack of quantitative estimates of human exposure to environmental bacteria, in general, and antibiotic-resistant bacteria, specifically, is a significant data gap hindering the assessment of effects on human health. The contribution of horizontal gene transfer to resistance in the environment and conditions that might foster the horizontal transfer of antibiotic resistance genes into human pathogens also need further research. Existing research has focused heavily on human health effects, with relatively little known about the effects of antibiotics and antibiotic resistance on natural and agricultural ecosystems. The proposed causal model is used to elucidate gaps in knowledge that must be addressed by the research community and may provide a useful starting point for the design and analysis of future research efforts

    Sustainability of Water Reclamation: Long-Term Recharge with Reclaimed Wastewater Does Not Enhance Antibiotic Resistance in Sediment Bacteria

    No full text
    Wastewater reclamation for municipal irrigation is an increasingly attractive option for extending water supplies. However, public health concerns include the potential for development of antibiotic resistance (AR) in environmental bacteria after exposure to residual pharmaceuticals in reclaimed water. Though scientific studies have reported high levels of AR in soils irrigated with wastewater, these works often fail to address the soil resistome, or the natural occurrence of AR. This study compared AR patterns in sediment Enterococcus isolated from water storage basins containing either reclaimed water or groundwater in central Arizona. Resistance to 16 antibiotics was quantified in isolates to a depth of 30 cm. Results reveal high levels of resistance to certain antibiotics, including lincomycin, ciprofloxacin, and erythromycin, exists in sediments regardless of the water source (groundwater, reclaimed water), and higher AR was not detectable in reclaimed water sediments. Furthermore, multiple-antibiotic-resistance (MAR) was substantially reduced in isolates from reclaimed water sediments, compared to freshwater sediment isolates. Comparing the development of AR in sediment bacteria at these two sites will increase awareness of the environmental and public health impacts of using reclaimed water for irrigation of municipal areas, and illustrates the necessity for control sites in studies examining AR development in environmental microbiota
    corecore