HR: 0800h
AN: H41C-0661    [Abstracts]
TI: Tetracycline Resistance in the Subsurface of a Poultry Farm: Influence of Poultry Wastes
AU: * You, Y
EM: you.yaqi@jhu.edu
AF: Department of Geography and Environmental Engineering, Johns Hopkins University, 313 Ames Hall, 3400 North Charles Street, Baltimore, MD 21218, United States
AU: Ball, W P
EM: bball@jhu.edu
AF: Department of Geography and Environmental Engineering, Johns Hopkins University, 313 Ames Hall, 3400 North Charles Street, Baltimore, MD 21218, United States
AU: Ward, M J
EM: mjward@jhu.edu
AF: Department of Geography and Environmental Engineering, Johns Hopkins University, 313 Ames Hall, 3400 North Charles Street, Baltimore, MD 21218, United States
AU: Hilpert, M
EM: markus_hilpert@jhu.edu
AF: Department of Geography and Environmental Engineering, Johns Hopkins University, 313 Ames Hall, 3400 North Charles Street, Baltimore, MD 21218, United States
AB: Concentrated animal feeding operations (CAFOs) are considered to be important man-made reservoir of antibiotic resistant bacteria. Using the electromagnetic induction (EMI) method of geophysical characterization, we measured the apparent subsurface electrical conductivity (EC_a) at a CAFO site in order to assess the movement of pollutants associated with animal waste. The map of EC_a and other available data suggest that (1) soil surrounding a poultry litter storage shed is contaminated by poultry waste, (2) a contamination plume in the subsurface emanates from that shed, and (3) the development of that plume is due to groundwater flow. We focused on understanding the spread of tetracycline resistance (Tc^{\mbox{\tiny R}}), because tetracycline is one of the most frequently used antibiotics in food animal production and therefore probably used at our field site. Microbiological experiments show the presence of Tc^{\mbox{\tiny R}} bacteria in the subsurface and indicate higher concentrations in the top soil than in the aquifer. Environmental DNA was extracted to identify CAFO- associated Tc^{\mbox{\tiny R}} genes and to explore a link between the presence of Tc^{\mbox{\tiny R}} and CAFO practices. A "shot-gun" cloning approach is under development to target the most prevalent Tc^{\mbox{\tiny R}} gene. This gene will be monitored in future experiments, in which we will study the transmission of Tc^{\mbox{\tiny R}} to naive E.~coli under selective pressure of Tc. Experimental results will be used to develop a mathematical/numerical model in order to describe the transmission process and to subsequently make estimates regarding the large-scale spread of antibiotic resistance.
DE: 1803 Anthropogenic effects (4802, 4902)
DE: 1831 Groundwater quality
DE: 1834 Human impacts
DE: 1847 Modeling
DE: 1871 Surface water quality
SC: Hydrology [H]
MN: 2007 Fall Meeting