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Full-Text Articles in Life Sciences
Isolation, Enumeration And Antibiotic Profiling Of Vibrio Vulnificus And V. Parahaemolyticus From Coastal Virginia, Stanley E. Peyton Jr.
Isolation, Enumeration And Antibiotic Profiling Of Vibrio Vulnificus And V. Parahaemolyticus From Coastal Virginia, Stanley E. Peyton Jr.
Masters Theses, 2020-current
Vibrio vulnificus and V. parahaemolyticus are gram-negative, halophilic bacteria that reside in estuarine waters and are associated with infections in humans. These bacteria can cause gastroenteritis through their presence in raw fish and shellfish consumed by humans. V. vulnificus can also produce wound infections leading to severe septicemia, and in some cases, death if not treated promptly. With increasing incidence of infections due to these two organisms, research efforts have focused on potential reservoirs and environmental conditions that can increase human exposure to, and infection, with these species of bacteria. This study was conducted in order to examine the role …
Whole Genome Sequence Analysis Of A Transmissible Multidrug-Resistance Plasmid Captured Without Cultivation From Poultry Litter, Emma C. Eisemann
Whole Genome Sequence Analysis Of A Transmissible Multidrug-Resistance Plasmid Captured Without Cultivation From Poultry Litter, Emma C. Eisemann
Senior Honors Projects, 2020-current
Use of antibiotics in the agricultural industry introduces selective pressure and, consequently, could increase the presence of antibiotic resistant organisms in surrounding environments. One such environment is litter (manure and bedding) produced during large-scale poultry production in the Shenandoah Valley. Litter, with its microorganisms, is commonly applied to fields within the Shenandoah River watershed. Antibiotic resistance (AR) and virulence genes are potentially transmissible between organisms through horizontal gene transfer of genetic mobile elements, for which poultry litter could be a reservoir. The typical, culture-based approach to detecting and analyzing AR plasmids and other mobile genetic elements is limited due to …
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 …
Antimicrobial Activity Of Novel Cationic Amphiphiles, Melanie Kusakavitch
Antimicrobial Activity Of Novel Cationic Amphiphiles, Melanie Kusakavitch
Senior Honors Projects, 2010-2019
This project focused on the development of amphiphiles in order to prevent hospital-acquired infections before they have a chance to enter the host, thereby reducing the need for antibiotics. The antibiotic resistance crisis of the 21st century is a dangerous epidemic with global consequences. Therefore, there is a desperate need for novel approaches in antimicrobial research. This would decrease the overall length of stay in hospitals and costs associated with such a stay. In this study, tetracationic amphiphiles with two 12-carbon chains and an aliphatic linker were studied. The MIC value of each amphiphile and strain pair was determined and …
Antibacterial Properties Of Novel Amphiphiles: Exploring Structure-Activity Relationships, Reafa Hossain
Antibacterial Properties Of Novel Amphiphiles: Exploring Structure-Activity Relationships, Reafa Hossain
Senior Honors Projects, 2010-2019
The increased cases of antibiotic resistance have large implication in hospital settings where infections by antibiotic resistant bacteria are harder to treat resulting in longer stays at the hospital, which drastically increases the costs to patients and hospitals. To address this matter, many research groups are searching for an alternative to antibiotics. One option is the development of amphiphiles, some of which have antibacterial properties. Amphiphiles contain a hydrophilic, polar head group, and a hydrophobic, nonpolar tail, which may intercalate into the cell membrane, resulting in cell lysis. Understanding the impact of amphiphile geometry on antibacterial activity allows for the …
Occurrence, Antibiotic Resistance, And Survival Of Fecal Enterococci In Turkey Litter, Steven Glynn Mcbride Ii
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
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 …
Transduction As The Method Of Horizontal Gene Transfer Of The Staphylococcal Chromosomal Cassette Mec (Sccmec), Amber B. Sauder
Transduction As The Method Of Horizontal Gene Transfer Of The Staphylococcal Chromosomal Cassette Mec (Sccmec), Amber B. Sauder
Senior Honors Projects, 2010-2019
Methicillin-resistant Staphylococcus aureus (MRSA) gains resistance to β-lactam antibiotics through a mutated penicillin binding protein (PBP2a) encoded on the SCCmec element. In combination with the recombinase encoded by ccr, these two genes are used as markers of the mobile genetic element (SCCmec). Due to recent increases in community acquired MRSA infections, the mechanisms of antibiotic resistance gene transfer have gained attention. Transduction, a method of horizontal gene transfer mediated by bacteriophage, is believed to be responsible for the movement of the SCCmec element. Recent studies have shown the transduction of the SCCmec element in clinical isolates; however, this study is …
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 …