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Full-Text Articles in Life Sciences

Increasing Antibiotic Resistance In Shigella Bacteria In The United States, William J. Pharr Nov 2020

Increasing Antibiotic Resistance In Shigella Bacteria In The United States, William J. Pharr

The Corinthian

Shigella bacteria cause half a million infections, 6,000 hospitalizations, and 70 deaths annually in the United States. These bacteria are of particular concern due to their high survivability, low infectious dose, and high adaptability. Cases of shigellosis from Shigella sonnei are becoming a more prevalent issue in the U.S. as the bacteria continues to develop higher resistance to today’s strongest antibiotics. Much of this resistance is connected to the exchange of genes between strains of Shigella due to insertion sequences (IS), intercontinental travel, and men who have sex with men (MSM). As a result of increased resistance, the use of …


Isolation, Enumeration And Antibiotic Profiling Of Vibrio Vulnificus And V. Parahaemolyticus From Coastal Virginia, Stanley E. Peyton Jr. Aug 2020

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 …


Lmea, A Conserved Cell-Envelope Protein In Mycobacteria, Is Important For Antibiotic Resistance And Cell Envelope Permeability, Sarah Hassan Osman Jul 2020

Lmea, A Conserved Cell-Envelope Protein In Mycobacteria, Is Important For Antibiotic Resistance And Cell Envelope Permeability, Sarah Hassan Osman

Masters Theses

The cell envelope of mycobacteria is critical for the survival and virulence of pathogenic species during infection, and its biosynthesis has been a proven drug target. Therefore, finding new targets in the biosynthetic pathway of cell envelope components is of great interest. Mycobacterium smegmatis is a model organism for the study of the devastating pathogen Mycobacterium tuberculosis. Previously, lipomannan elongation factor A (LmeA) has been identified as a cell envelope protein that is critical for the control of mannan chain length of lipomannan (LM) and lipoarabinomannan (LAM), lipoglycan components of the cell envelope. The deletion mutant, ∆lmeA, accumulates abnormal LM/LAM …


Contributions Of Gyra And Parc Mutations And Qnrs2 Acquisition To Ciprofloxacin Resistance In Aeromonas Veronii Hm21, Daniel J. Silverstein Jun 2020

Contributions Of Gyra And Parc Mutations And Qnrs2 Acquisition To Ciprofloxacin Resistance In Aeromonas Veronii Hm21, Daniel J. Silverstein

Honors Scholar Theses

In recent years, ciprofloxacin resistant (CpR) Aeromonas veronii and A. hydrophila strains have been isolated from the wounds of patients receiving leech therapy. Genome comparisons of these CpR isolates revealed the presence of chromosomal mutations in gyrA and parC as well as the gain of qnrS2 on either a large, 34 kb, conjugatable, low-copy plasmid, pAv42, or on a small, 6.8 kb, high-copy plasmid, pAh1471. The minimum inhibitory concentration, MIC, for Cp of these clinical isolates ranged from 1 to ≥32 µg/mL and some harbored a qnrS2 containing plasmid. We wanted to assess the contributions of these factors in an …


Whole Genome Sequence Analysis Of A Transmissible Multidrug-Resistance Plasmid Captured Without Cultivation From Poultry Litter, Emma C. Eisemann May 2020

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 …


The Effects Of Farnesol, A Quorum Sensing Molecule From Candida Albicans, On Alcaligenes Faecalis, Savannah Hutson May 2020

The Effects Of Farnesol, A Quorum Sensing Molecule From Candida Albicans, On Alcaligenes Faecalis, Savannah Hutson

Undergraduate Honors Theses

Quorum sensing molecules have become a recent focus of study to learn if and how they can be used, both on their own and in conjecture with current antimicrobial methods, as a means of bacterial control. One such quorum sensing molecule is the sesquiterpene alcohol, Farnesol, which is synthesized and released by the fungus, Candida albicans. In most in-vivo cases, our laboratory has shown that Alcaligenes faecalis overtakes C. albicans, preventing its growth. However, as a way to counteract this inhibitory effect, Farnesol may be one way that Candida has found to fight back. In this study, we …


Characterization Of The Broad-Spectrum Inhibitory Capability Of Alcaligenes Faecalis And A. Viscolactis Against Potential Pathogenic Microorganisms, Andrew Fuqua May 2020

Characterization Of The Broad-Spectrum Inhibitory Capability Of Alcaligenes Faecalis And A. Viscolactis Against Potential Pathogenic Microorganisms, Andrew Fuqua

Undergraduate Honors Theses

The recent rise of multidrug resistant microorganisms has grown from an isolated concern to a massive public health crisis. It has become imperative that scientists look for new ways to combat this issue. Due to the selective pressures of competition, bacteria and other microbes possess a host of defenses and weapons designed to exploit vulnerabilities in other microorganisms. Consequently, the study of these systems and microbial interactions has much to reveal in the search for novel antimicrobial treatments. Previous research from our laboratory has discovered that both Alcaligenes faecalis and Alcaligenes viscolactis, two rarely studied and generally non-virulent bacteria, …


Antibiotic Resistant Bacteria, Antibiotic Resistance Genes And Potential Drivers In The Aquatic Environments, Shuo Shen May 2020

Antibiotic Resistant Bacteria, Antibiotic Resistance Genes And Potential Drivers In The Aquatic Environments, Shuo Shen

Dissertations

As antibiotic resistance genes in aquatic environment have been increasing across the world, affecting water quality and public health, many studies documented concentrations of antibiotic resistance genes and some studies discussed their potential drivers. However, systematic and quantitative reviews that link antibiotic resistance genes (ARGs) to anthropogenic and environmental factors are limited. Nevertheless, this information will be important for developing regulation policy on controlling antibiotic use and therefore reducing potential risks to antibiotic resistance. I conducted meta-analysis of ARGs concentration at a global scale using Bayesian inference to explore climatic and socio-economic factors as drivers. I found local-scale climatic variables …


Identification Of Uncommon Antibiotic-Producing Illinois Soil Isolates, Lesly Muniz, Dr. Lori Scott Jan 2020

Identification Of Uncommon Antibiotic-Producing Illinois Soil Isolates, Lesly Muniz, Dr. Lori Scott

Identifying and Characterizing Novel Antibiotic Producing Microbes From the Soil

This project is a collaboration with the Tiny Earth Project Initiative (TEPI), which is a global network of educators and students focused on student sourcing antibiotic discovery from the soil. We researched tester strains B. subtilis and E. coli from the soil isolates obtained. We further verified if the isolates were common antibiotic bacteria. Unfortunately, this project heavily relied on biochemical tests, colony morphology, and Gram stains to reject or fail to reject our hypothesis. Our goal was to discover new antibiotic-producing bacteria that could be beneficial in combating ESKAPE strains. A proper PCR and DNA extraction would be required …


Isolated Antibiotic Producing Bacteria In Local Soil Samples Determined To Be Bacillus, Cassidy Potter, Dr. Lori Scott Jan 2020

Isolated Antibiotic Producing Bacteria In Local Soil Samples Determined To Be Bacillus, Cassidy Potter, Dr. Lori Scott

Identifying and Characterizing Novel Antibiotic Producing Microbes From the Soil

Nosocomial pathogens are multi-drug resistant to antibiotics that fight bacterial infections posing danger to the public health, the most dangerous of them being the ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.). This project is a collabortaion with the TIny Earth Project Initiative (TEPI), which is a global network of educators and students focused on studentsourcing antibiotic discovery from the soil. TEPI allows student-led research on local soil samples from Bettendorf, IA to discover potential novel antibiotic producing bacteria that could potentially treat ESKAPE pathogens and reduce public health risk. Two soil isolates …


Pseudomonas And Bacillus Soil Isolates Produce Antibiotics, Chelsea Brandt, Dr. Lori Scott Jan 2020

Pseudomonas And Bacillus Soil Isolates Produce Antibiotics, Chelsea Brandt, Dr. Lori Scott

Identifying and Characterizing Novel Antibiotic Producing Microbes From the Soil

The recent emergence of antibiotic resistance bacterial strains presents a significant challenge and threat to human healthcare. While new methods of treatment such as bacteriophage therapy and combinations of existing antibiotics are being researched, the human population is in dire need of new antibiotics to replace those that are ineffective. This research addresses this need by identifying antibiotic producing bacteria in a soil sample from Davenport, IA. This project is a collaboration with the Tiny Earth Project Initiative (TEPI), which is a global network of educators and students focused on studentsourcing antibiotic discovery from soil. Microbiology lab techniques and 16S …


Identification Of Antibiotic Producing Soil Bacteria Against Bacillus Subtilis, Morgan Brockhouse, Dr. Lori Scott Jan 2020

Identification Of Antibiotic Producing Soil Bacteria Against Bacillus Subtilis, Morgan Brockhouse, Dr. Lori Scott

Identifying and Characterizing Novel Antibiotic Producing Microbes From the Soil

This project is a collaboration with the Tiny Earth Project Initiative (TEPI), which is a global network of educators and students focused on student-sourcing antibiotic discovery from soil. Individual strains of soil bacteria were isolated and produced antibiotic against Bacillus subtilis. Two of these samples were sequenced using the 16S rRNA gene to reveal they are very closely related to the genus Pseudomonas.


Group B Streptococcus: Molecular Epidemiology, Pathogenic Profiling And Control Strategies, Katherine Mary Hayes Jan 2020

Group B Streptococcus: Molecular Epidemiology, Pathogenic Profiling And Control Strategies, Katherine Mary Hayes

Theses

Group B Streptococcus (GBS) are frequent colonisers of the gastrointestinal tract of healthy adults with worldwide rates of 18% colonisation; however, they are also opportunistic pathogens capable of causing invasive disease, particularly in neonates and adults with underlying conditions. Indeed, GBS is the leading cause of invasive neonatal disease worldwide with a global incidence of 0.49 per 1000 live births and GBS disease in adults is increasing globally, with estimated rates of 10.9 cases per 100,000 people. While GBS remain largely susceptible to penicillin, there have been reports of reduced beta-lactam susceptibility in certain countries and resistance to other antibiotic …


Development Of Small Molecule Antibiotics Against A Conserved Rna Gene Regulatory Element In Gram-Positive Bacteria, Ville Yrjö Petteri Väre Jan 2020

Development Of Small Molecule Antibiotics Against A Conserved Rna Gene Regulatory Element In Gram-Positive Bacteria, Ville Yrjö Petteri Väre

Legacy Theses & Dissertations (2009 - 2024)

Bacterial infections and the rise of antibiotic resistance, especially multidrug resistant strains, have generated a clear need for discovery of novel therapeutics. Most antibiotics in use today are derivatives of previous antibiotics to which resistance mechanisms already exist, and traditionally they have a single target: either a protein or rRNA. Gram-positive bacteria regulate the expression of several essential genes or operons using a mechanism called the T-box. The T-box is a structurally conserved riboswitch-like gene regulator in the 5’-untranslated region (UTR) of numerous essential genes of Gram-positive bacteria. T-boxes are stabilized by cognate, unacylated tRNA ligands, allowing the formation of …