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Full-Text Articles in Engineering

Occurrence And Persistence Of Antibiotics Administered To Cattle In A Newly Established Feedlot, Brittany Trejo Apr 2020

Occurrence And Persistence Of Antibiotics Administered To Cattle In A Newly Established Feedlot, Brittany Trejo

Department of Environmental Engineering: Theses and Student Research

The common practice of using therapeutic antibiotics in livestock farming is a worldwide phenomenon. Over the last decade, there has been a growing concern of antibiotics entering the environment via animal manure. Similar studies have focused on the occurrence and biological effects of antibiotics in land-applied animal feedlots; however, limited research has been conducted on the occurrence and persistence of antibiotics in animal feedlots. A study was conducted to investigate the occurrence and persistence of four injected antibiotics (ceftiofur enrofloxacin, florfenicol, and tulathromycin) and two continuously fed antibiotics (monensin and tylosin) in feedlot sediment, runoff, and sediment runoff. For antibiotics …


Fate Of Antimicrobials And Antimicrobial Resistance Genes In Simulated Swine Manure Storage, Stacey R. Joy, Xu Li, Daniel D. Snow, John Gilley, Bryan L. Woodbury, Shannon L. Bartelt-Hunt Jan 2014

Fate Of Antimicrobials And Antimicrobial Resistance Genes In Simulated Swine Manure Storage, Stacey R. Joy, Xu Li, Daniel D. Snow, John Gilley, Bryan L. Woodbury, Shannon L. Bartelt-Hunt

School of Natural Resources: Faculty Publications

The behavior of three antibiotics (bacitracin, chlortetracycline, and tylosin) and two classes of antibiotic resistance genes (ARGs), tet and erm, were monitored in swine manure slurry under anaerobic conditions. First-order decay rates were determined for each antibiotic with half-lives ranging from1 day (chlortetracycline) to 10 days (tylosin). ARGs were monitored in the swine manure slurry, and losses of approximately 1 to 3 orders of magnitude in relative abundance were observed during the 40 day storage period. First-order degradation profiles were observed for chlortetracycline and its corresponding resistance genes, tet(X) and tet(Q). Tylosin was degraded to approximately 10% …


Effects Of The Antimicrobial Tylosin On The Microbial Community Structure Of An Anaerobic Sequencing Batch Reactor, Toshio Shimada, Xu Li, Julie L. Zilles, Eberhard Morgenroth, Lutgarde Raskin Jan 2010

Effects Of The Antimicrobial Tylosin On The Microbial Community Structure Of An Anaerobic Sequencing Batch Reactor, Toshio Shimada, Xu Li, Julie L. Zilles, Eberhard Morgenroth, Lutgarde Raskin

Department of Civil and Environmental Engineering: Faculty Publications

The effects of the antimicrobial tylosin on a methanogenic microbial community were studied in a glucosefed laboratory-scale anaerobic sequencing batch reactor (ASBR) exposed to stepwise increases of tylosin (0, 1.67, and 167 mg/L). The microbial community structure was determined using quantitative fluorescence in situ hybridization (FISH) and phylogenetic analyses of bacterial 16S ribosomal RNA (rRNA) gene clone libraries of biomass samples. During the periods without tylosin addition and with an influent tylosin concentration of 1.67 mg/L, 16S rRNA gene sequences related to Syntrophobacter were detected and the relative abundance of Methanosaeta species was high. During the highest tylosin dose of …