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Full-Text Articles in Life Sciences

Assessing The Prevalence Of Multidrug Resistant Salmonella Enterica From Stream Sediment And Poultry Litter In The Shenandoah Valley Of Virginia, Noah Greenman Jan 2019

Assessing The Prevalence Of Multidrug Resistant Salmonella Enterica From Stream Sediment And Poultry Litter In The Shenandoah Valley Of Virginia, Noah Greenman

Masters Theses, 2010-2019

Multidrug resistant Salmonella enterica present in stream sediment and poultry litter represent a critical health concern. A small number of S. enterica serotypes are responsible for most lab-confirmed infections in the US each year. To assess the prevalence of these significant strains, we isolated 88 S. enterica from stream sediment and poultry litter. Sequence data for all isolates were generated using an Illumina® sequencing platform, with long-reads for some isolates from the Oxford Nanopore MinION™ used in a hybrid genome assembly approach. Isolates were typed according to their serotype and multi-locus sequence type using SeqSero/SISTR and Enterobase respectively. Antibiotic resistance …


Occurrence, Antibiotic Resistance, And Survival Of Fecal Enterococci In Turkey Litter, Steven Glynn Mcbride Ii Dec 2016

Occurrence, Antibiotic Resistance, And Survival Of Fecal Enterococci In Turkey Litter, Steven Glynn Mcbride Ii

Masters Theses, 2010-2019

The United States Environmental Protection Agency’s National Water Quality Inventory and the Commonwealth of Virginia’s 305(b)/303(d) Water Quality Assessment Integrated Report show fecal bacteria to be the most common cause of impairment for both streams and estuaries. Human and animal sources have both been identified as significant contributors of pathogenic bacteria to surface waters. In this study, turkey litter from a farm in Shenandoah County, VA was surveyed for total culturable bacteria and total culturable enterococci before and after a transition to organic rearing practices. The enterococci were identified to species phenotypically using the Biolog Microbial Identification System and resistance …


Next-Generation Sequencing Of A Multi-Drug Resistance Plasmid Captured From Stream Sediment, Kevin G. Libuit May 2016

Next-Generation Sequencing Of A Multi-Drug Resistance Plasmid Captured From Stream Sediment, Kevin G. Libuit

Masters Theses, 2010-2019

Plasmids in agriculturally-impacted bodies of water may play a significant role in the dissemination of antibiotic resistance. Previously, Erika Gehr, as part of her M.S. thesis work in our laboratory, captured environmental plasmids without cultivation of host bacteria from stream sediment into Escherichia coli. Individual plasmids were capable of conferring resistance to a surprising array of antibiotics including aminoglycosides and extended-spectrum β-lactams. In this study, we developed a method to sequence multi-drug resistance plasmids using both Oxford Nanopore MinION and Ion Torrent Personal Genome Machine sequencers. Plasmid pEG1-1 was sequenced on both platforms and a hybrid assembly utilizing data …


The Potential For Replication And Transmission Of Antibiotic Resistance Plasmids In An E. Coli Population In Agriculturally Impacted Stream Sediment, Erika Gehr May 2013

The Potential For Replication And Transmission Of Antibiotic Resistance Plasmids In An E. Coli Population In Agriculturally Impacted Stream Sediment, Erika Gehr

Masters Theses, 2010-2019

The use of antibiotics in agriculture is thought to be a major cause of resistance in microorganisms found in the environment. Horizontal transfer of genetic information from transient to native and from native to transient bacterial populations may enhance the spread and recombination of resistance genes and might play a role in the formation of multi-resistant organisms in environmental reservoirs. Tetracycline resistance plasmids were compared using three isolation techniques -- traditional “endogenous” extraction from isolates, “exogenous” plasmid capture, and direct plasmid extraction from sediment --to determine the potential for plasmid born resistance in an E. coli population found in agriculturally-impacted …