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Articles 1 - 19 of 19

Full-Text Articles in Organisms

Investigation On Bacterial Signaling Through Generation Of A Ppgpp Biosensor, Andrew Robinson May 2022

Investigation On Bacterial Signaling Through Generation Of A Ppgpp Biosensor, Andrew Robinson

Undergraduate Honors Theses

Guanosine tetraphosphate (ppGpp) is a bacterial signaling molecule involved in activating the stringent response, a cellular reaction to environmental stress that downregulates cell division and metabolism processes to conserve nutrients. The stringent response is implicated in some instances of antibiotic persistence, so broadening the current understanding of ppGpp signaling is useful. This thesis seeks to generate a ppGpp biosensor that will bind ppGpp and emit fluorescent light in its presence, which will allow for improved research into the pathways and functions of the signaling molecule. To generate a novel ppGpp biosensor, I converted a biosensor previously used to detect cyclic …


Genital Chlamydia Infection Is Influenced By The Female Sex Hormones Estrogen And Progesterone In Vivo, Amy Gail Gravitte Dec 2021

Genital Chlamydia Infection Is Influenced By The Female Sex Hormones Estrogen And Progesterone In Vivo, Amy Gail Gravitte

Electronic Theses and Dissertations

Chlamydia is the most common bacterial sexually transmitted infection in the United States and worldwide. It often goes unnoticed due to lack of symptoms and left untreated it can ascend the female genital tract to cause sequelae like pelvic inflammatory disease and irreversible tubal infertility. In reproductive-aged women, female sex hormones estrogen (E2) and progesterone (P4) concentrations fluctuate during the menstrual cycle and are influenced by hormonal contraceptives and hormone replacement therapy. E2 and P4 influence genital Chlamydia infection in women and mice, but these multifactorial interactions are not entirely mapped out. The complex interplay of E2 and P4 with …


Hemin Utilization In Rhizobium Leguminosarum Atcc 14479, John Lusby May 2021

Hemin Utilization In Rhizobium Leguminosarum Atcc 14479, John Lusby

Electronic Theses and Dissertations

Rhizobium leguminosarum is a Gram negative, motile, nitrogen-fixing soil bacterium. Due to the scarcity of iron in the soil bacteria have developed a wide range of iron scavenging systems. The two types of iron scavenging systems used are indirect and direct. In-silico analysis of the genome identified a unique direct iron scavenging system the Hmu operon. This system has been identified in other closely related rhizobium species and is believed to be involved in utilizing heme compounds as a sole source of iron. We have attempted to characterize the role of the Hmu operon in iron utilization by monitoring the …


The Inhibitory Effects Of An Antimicrobial Gel On The Staphylococcus Species, Mara Trinkle Aug 2020

The Inhibitory Effects Of An Antimicrobial Gel On The Staphylococcus Species, Mara Trinkle

Undergraduate Honors Theses

The prevalence of antibiotic resistant bacteria has made the choices for topical treatments for patients who experience burns wounds extremely limited. The Staphylococcus genus is naturally occurring in and on the human body but can become harmful once it enters the bloodstream. A novel antimicrobial gel has been shown by our laboratory to inhibit both the planktonic growth and biofilm formation of Staphylococcus aureus in previous studies. The antimicrobial gel is made of seven natural compounds including antioxidants (vitamin C and E). We wanted to examine the effects of the antimicrobial gel on numerous other Staphylococcal species because it is …


Second Messenger Cyclic-Di-Gmp Regulation In Acinetobacter Baumannii, Justin Deal May 2020

Second Messenger Cyclic-Di-Gmp Regulation In Acinetobacter Baumannii, Justin Deal

Undergraduate Honors Theses

Over time, “superbugs,” or bacteria that have become resistant to antibiotics, have become a great concern in modern medicine. Viable alternates are currently being looked into as effective and safe ways to prevent or treat infections caused by these superbugs. One such method is through the utilization of the second messenger molecule cyclic-di-GMP (c-di-GMP) that has been shown to regulate phenotypes within other bacteria that may control surface colonization in Acinetobacter baumannii. Through a series of experiments, the active enzymes that create c-di-GMP - diguanylate cyclases - and break down c-di- GMP - phosphodiesterases - have been inactivated in …


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 …


Subcellular Localization Of Tobacco Sabp2 Under Normal And Stress Conditions, Sanjeev Das May 2020

Subcellular Localization Of Tobacco Sabp2 Under Normal And Stress Conditions, Sanjeev Das

Undergraduate Honors Theses

Subcellular Localization of Tobacco SABP2 under Normal and Stress Conditions

Salicylic acid (SA), a phytohormone, plays an important role in plant physiology. SA mediated innate immune pathway is an important pathway for plant immunity against pathogens. Plants resisting pathogen infection synthesize higher levels of Methyl Salicylate (MeSA), which is then converted to SA by the esterase activity of Salicylic Acid Binding Protein 2 (SABP2). The high level of the converted SA leads to enhanced pathogen resistance. The study of subcellular localization of a protein is critical in explaining its potential biochemical functions. SABP2 tagged with eGFP was expressed transiently in …


The Effect Of Alcaligenes Faecalis On Inhibition Of Candida Albicans Biofilm And Planktonic Growth, Nausheen A. Siddiqui May 2020

The Effect Of Alcaligenes Faecalis On Inhibition Of Candida Albicans Biofilm And Planktonic Growth, Nausheen A. Siddiqui

Undergraduate Honors Theses

Candida albicans is a fungal microorganism found on the human body and in the environment. An opportunistic pathogen causing local and systemic infection, this fungus is one of the leading causes of nosocomial infections. More alarming is its growing resistance against the limited number of antifungals we have for treatment Candida infections. An area of current research, termed polymicrobial interactions, focuses on how different microorganisms interact with each other for limited space, nutrients, and survival. The current study focuses on attempting to inhibit planktonic and biofilm growth stages by using the benign bacterium Alcaligenes faecalis, previously shown in our …


A Study Of The Polymicrobial Inhibitory Interactions Between Alcaligenes Faecalis And Staphylococcus Aureus, Blakeley Griffin May 2020

A Study Of The Polymicrobial Inhibitory Interactions Between Alcaligenes Faecalis And Staphylococcus Aureus, Blakeley Griffin

Undergraduate Honors Theses

Members of the Staphylococcus genus are found as a part of normal microflora in humans and can commonly be found on the skin or in the nasal cavity. However, these microorganisms can cause serious and life-threatening opportunistic infections when there is a break in the physical barrier of skin. These infections have become difficult to treat as resistant strains emerge, particularly Methicillin Resistant Staphylococcus aureus (MRSA). MRSA has become a commonly acquired nosocomial infection which is difficult to treat with conventional antibiotics of the blactam class. Even Vancomycin, a last resort antibiotic, has been ineffective on some infections. Furthermore, …


The Role Of Non-Neuronal Acetylcholine In Urogenital Chlamydial Infection, Jessica R. Lockhart Dec 2018

The Role Of Non-Neuronal Acetylcholine In Urogenital Chlamydial Infection, Jessica R. Lockhart

Electronic Theses and Dissertations

Chlamydia trachomatiscauses a bacterial sexually transmitted infection, Chlamydia, that is often chronic and casues reproductive complications in women. We hypothesized that Chlamydia infection increases local acetylcholine (ACh) production, which regulates the host’s inflammatory response to the infection. Female mice infected with C. muridarumwere sacrificed at days 3, 9, 15, and 21 post-infection, genital tract tissues harvested, and immunohistochemistry performed to enumerate ACh-producing cells. Infection increased the number of ACh-producing cells in cervical tissue at days 3,15, and 21 post-infection (pi), uterine tissue at day 3 and 9 pi, and ovarian tissue day 3, 15, and 21 pi. These …


The Inhibitory Effects Of A Novel Gel On Staphylococcus Aureus Biofilms, Lindsey Vance May 2018

The Inhibitory Effects Of A Novel Gel On Staphylococcus Aureus Biofilms, Lindsey Vance

Undergraduate Honors Theses

Antibiotic resistance is an ever-growing topic of concern within the medical field causing researchers to examine the mechanisms of resistance to develop new antimicrobials. Bacteria’s ability to form biofilms is one mechanism which aids in antimicrobial resistance. Staphylococcus aureus is of special interest as it is one of the most frequent biofilm-forming bacteria found on medical devices causing infections and posing dangerous threats in a clinical setting. A recently developed antimicrobial gel has been shown to have profound effects on treating bacterial infections and wound healing. This research is centered upon examining the antimicrobial effects of this gel on the …


Pantoea Agglomerans Bacteremia: A Rare Case Of Spontaneous Human Infection By A Plant Pathogen In An Immunocompromised Host., Utsab R. Panta, James A. Joslyn, Rupal D. Shah Apr 2018

Pantoea Agglomerans Bacteremia: A Rare Case Of Spontaneous Human Infection By A Plant Pathogen In An Immunocompromised Host., Utsab R. Panta, James A. Joslyn, Rupal D. Shah

Appalachian Student Research Forum

Introduction:

Pantoea agglomerans is a Gram negative ubiquitous bacteria commonly isolated from plant surfaces, seeds, fruits and animal/human feces usually introduced to human by ingestion of infected fruits/vegetables, thorn pricks and gastrointestinal translocation in lack of stomach acidity. However, the pathogen can also cause opportunistic human infection especially when the immune system is impaired. The aim of this case report is to investigate clinical features in a patient with P. agglomerans bacteremia and bring attention the opportunistic infection by this rare bacteria.

Case presentation:

We present a case of 57 year old caucasian lady with past medical history …


Effects Of Acute Sepsis On Renal Structure And Sympathetic Innervation In Mice, Tuqa Alkhateeb Aug 2017

Effects Of Acute Sepsis On Renal Structure And Sympathetic Innervation In Mice, Tuqa Alkhateeb

Electronic Theses and Dissertations

Sympathetic nerves are important for renal physiology and sepsis pathophysiology. A recent study showed sprouting of sympathetic nerves in spleen of septic mice. This study was done to test if renal sprouting of sympathetic nerves also happens and to investigate renal morphology in septic mice. Cecal ligation and puncture (CLP) was used to induce sepsis and kidneys were removed for evaluation. Bowman’s space was diminished with cortical bubble cells present suggestive of acute renal pathology, however, renal function was unchanged. Acute sepsis did not affect either renal sympathetic innervation or non-neuronal cholinergic cells. Mouse kidneys had more epinephrine (EPI) than …


Chat Expression In Chlamydia Muridarum-Infected Female Murine Genital Tract, Hallie Sartain May 2017

Chat Expression In Chlamydia Muridarum-Infected Female Murine Genital Tract, Hallie Sartain

Undergraduate Honors Theses

Chlamydia trachomatis is the most prevalent agent of bacterial sexually transmitted infections in the world. However, a profuse number of cases are unreported, as the infection is often asymptomatic. Sequelae such as pelvic inflammatory disease, an increased risk of cervical cancer, premature birth, and perinatal infections in pregnant women can occur. Inflammation occurs in the body in response to infection or injury. Although inflammation can lead to some unwanted secondary effects, such as pain, it serves to return the body to homeostasis by restoring injured tissues and eliminating pathogens. One recently identified connection between the central nervous system and the …


Determination Of The Effects That A Previously Uncharacterized Secreted Product From Klebsiella Pneumoniae Has On Citrobacter Freundii And Enterobacter Cloacae Biofilms, Cody M. Hastings May 2017

Determination Of The Effects That A Previously Uncharacterized Secreted Product From Klebsiella Pneumoniae Has On Citrobacter Freundii And Enterobacter Cloacae Biofilms, Cody M. Hastings

Undergraduate Honors Theses

More so than ever, Multiple Drug Resistant (MDR) bacteria are on the rise due to overuse of antibiotics along with natural selection for adaptations that enhance drug-resistant properties. One particular bacterial family, Enterobacteriaceae, has been problematic, exhibiting several bacterial members that have developed a precipitous resistance to modern antibiotics and are also primary causative agents of nosocomial, or hospital acquired, infections. Citrobacter freundii (CF) and Enterobacter cloacae (ECL) are two species of the Enterobacteriaceae family causing significant medical concern due to their role in producing numerous opportunistic infections such as bacteremia, lower respiratory tract infections, urinary tract infections, and endocarditis. …


Range-Wide Prevalence And Impacts Of Pseudocercosporella Inconspicua On Lilium Grayi And An Assessment Of L. Superbum And L. Michauxii As Reservoirs, Cindy L. Barrett May 2017

Range-Wide Prevalence And Impacts Of Pseudocercosporella Inconspicua On Lilium Grayi And An Assessment Of L. Superbum And L. Michauxii As Reservoirs, Cindy L. Barrett

Electronic Theses and Dissertations

Lilium grayi (Gray’s Lily), a southern Appalachian endemic species, is threatened by a Lilium-specific fungal pathogen, Pseudocercosporella inconspicua. The disease is characterized by tan lesions that can cause early senescence, while also lowering seed production and viability. This project tested for P. inconspicua conidia and accessed health at nine locations. The disease was present and ubiquitous across the range of L. grayi. Through identification of P. inconspicua conidia in the field, L. superbum (Turk’s Cap Lily) was identified as an additional host, while L. michauxii (Michaux’s Lily) was disease-free. However, infection was inducible in both species. With …


Identification Of Transcription Factors Gzf3, Rfx1, Orf19.3928 As Being Implicated In Candida-Bacterial Interactions., Joni Watson May 2015

Identification Of Transcription Factors Gzf3, Rfx1, Orf19.3928 As Being Implicated In Candida-Bacterial Interactions., Joni Watson

Undergraduate Honors Theses

Candida albicans is an opportunistic pathogen that is present in the normal flora in a majority of individuals. One key factor in C. albicans virulence is the ability to change its morphology from yeast to an elongated or hyphal form. The regulation of this morphogenesis relies in part upon quorum sensing (QS) molecules. C. albicans often exists as part of a mixed culture alongside other microbes and is influenced by their presence as well as the presence of QS molecules that they produce. In this study, a library of diploid homozygous transcriptional regulator knockout (TRKO) mutants were screened to identify …


Potential Role Of Rta3 And Gnp3 Transport Genes In The Quorum Sensing Response Of Candida Albicans, John G. Magnuson May 2015

Potential Role Of Rta3 And Gnp3 Transport Genes In The Quorum Sensing Response Of Candida Albicans, John G. Magnuson

Undergraduate Honors Theses

Quorum sensing (QS) is a mechanism of communication between cells to coordinate biological activities. In the opportunistic fungal pathogen Candida albicans, QS is important for regulating the organism’s ability to change morphology from a yeast form to a hyphal form. Previously, our laboratory identified several genes involved in polymicrobial communication between C. albicans and three bacterial species. We hypothesize that interspecies communication and QS utilize the same genetic pathways to control C. albicans morphological behavior. In this study, two transport genes, RTA3 and GNP3, and their involvement in QS were examined. To test whether these two genes participate in QS, …


Regulating Rsma Expression In Pseudomonas Aeruginosa, Sean D. Stacey Aug 2013

Regulating Rsma Expression In Pseudomonas Aeruginosa, Sean D. Stacey

Electronic Theses and Dissertations

Pseudomonas aeruginosa, a Gram-negative bacillus, commonly infects immunocompromised individuals and uses a variety of virulence factors to persist in these hosts. The posttranscriptional regulator, RsmA, plays a role in the expression of many virulence factors in P. aeruginosa. RsmA up regulates virulence factors used in colonizing hosts. However, regulation of rsmA is not well elucidated. Transposon mutagenesis was performed on P. aeruginosa containing a transcriptional rsmA-lacZ fusion to answer this question. Mutants were screened via β-galactosidase assay and transposon insertions identified via arbitrary PCR. A probable MFS transporter, we named mtpX, was one significant transposon mutant identified. …