Microbiology Commons^™

Evaluation Of Nickel Stress On Anabaena Cylindrica, Danielle L. Maragh

Seton Hall University Dissertations and Theses (ETDs)

Heavy metal contamination due to anthropogenic activities has steadily been on the rise over the past few decades. Cyanobacteria can thrive in water bodies that have been contaminated by heavy metal runoffs and are able to tolerate heavy metal stress even in relatively high concentrations. Cyanobacterial species can secrete toxins which can prove harmful to humans and life stock. Due to their high adaptation to heavy metal stress, understanding the potential mechanism behind their response may lead to solutions in curbing excessive cyanobacterial growth especially in water bodies that serves as sources of drinking water. Anabaena spp. is a genus …

Implementing Crispr-Cas9 Gene Editing System In Microbotryum., Stevana Reese Schauer

College of Arts & Sciences Senior Theses

Microbotryum dianthorum is a species of smut fungus which causes infection in plants in the Dianthus genus. The infection process is aided by small-secreted proteins known as effectors. Effectors may aid in the infection process because they are secreted by the fungus and can enter plant tissue, possibly to facilitate infection and/or manipulate the host. Thus, it is of interest to investigate the genes for these effectors to determine their role in the infection process. One method to study genes is through gene disruption, via the CRISPR/Cas9 gene editing system, but this has not yet been implemented in Microbotryum dianthorum …

How Acetylation Regulates Metabolic Enzyme Function During Environmental Shifts, Jared Canonigo

Biological Sciences Undergraduate Honors Theses

Organisms such as Saccharomyces cerevisiae can regulate the mechanisms of proteins through post-translational modification. These modifications play a vital role in functional proteomic activity because they can regulate protein activity, localization, and interaction with other cellular molecules. Such modifications include phosphorylation, methylation, and acetylation. The metabolic mechanisms of yeast became of keen interest to our lab because our lab noticed many stress defense proteins were being acetylated during stress heat shock. Notably, Adh1p and Adh2p showed both an increase and a decrease in acetylation at two lysine residues (K315 and K314) overtime during heat shock respectively, though the exact function …

Identification Of Proteins That Contribute To Yeast Heat Stress By Lysine Acetylation, Weijia Shi

Biological Sciences Undergraduate Honors Theses

Evidence is emerging that protein lysine acetylation may be a novel type of post-translational modification (PTM) contributing to the mechanisms of yeast heat stress responses. Proteomics studies including ours have identified over 1,000 acetylated proteins in the yeast proteomes that are composed of about 6,000 proteins. Our lab recently identified 596 proteins that underwent acetylation changes during heat shock by mass spectrometry. However, the role of lysine acetylation on specific residues of specific proteins in yeast thermotolerance remains largely unknown. This study selected 43 proteins from our lab’s previous work and examined their possible contributions to yeast heat stress responses. …

Contaminated Mycoscapes: Designing With Living Organisms, Maria Gutierrez, Elise Zilius

Architecture Senior Theses

The Anthropocene has stripped the planet of its resources, leaving behind an abundance of contamination. The built environment no longer meets the standards set by our turbulent planet. Humankind has lost the privilege of agency in design and construction. Construction methods have failed to evolve concurrently to the intense accumulation of waste; remaining firmly rooted in the materiality of the past, they have upheld architectural notions of stagnancy, cleanliness, and hygiene and ignore the rapidly changing conditions of the environment. This investigation uses contamination to fuel mycelial growth and construct emergent forms whilst executing remediation strategies for polluted sites of …

How Historic Shipwrecks Influence Dispersal Of Deep-Sea Microbiomes, Rachel Moseley

Master's Theses

This thesis investigates how historic shipwrecks potentially shape dispersal of deep-sea microbiomes. Processes impacting dispersal of microbiomes around artificial structures in the ocean and how they connect to other deep-sea habitats is unknown. Dispersal processes are explained for some macroorganisms by theories in ecology, specifically the Theory of Island Biogeography and the Wooden Stepping Stone hypothesis. These have not been investigated for microorganisms, and thus this work will probe if they are applicable to microbial biogeography in this habitat. Experiments were conducted to establish new “island-like” features in near proximity (25-125 m) to wooden-hulled historic shipwrecks in the northern Gulf …

Partial Expression Of The Vbss Gene In Rhizobium Leguminosarum Atcc 14479 And In-Silico Analysis Of The Vbs Gene Cluster In Various Microorganisms, Afreen Siddiqui

Undergraduate Honors Theses

Iron is extremely important for many organisms. Despite its abundancy, it exists in insoluble forms that makes its usability difficult. Some organisms secrete siderophores, low molecular weight compounds, that can chelate iron and convert it into usable forms for cells. One such organism, Rhizobium leguminosarum, is a nitrogen fixing symbiont proteobacteria that infects leguminous plants. The genome of Rhizobium leguminosarum ATCC 14479, which infects the red clover, Trifoli pratense, has previously been completely sequenced in our lab. Our lab has identified several genes in this strain involved in the biosynthesis of a siderophore, vicibactin. The protein product of one of …

The Impact Of Oxygen Availability And Oxidative Stress On Regulation Of Cyclic-Dimeric-Gmp In Listeria Monocytogenes Strain F2365, Anna G. Welch

Honors Theses

Listeria monocytogenes is a gram-positive foodborne pathogen that results in the infectious disease listeriosis. The second messenger molecule cyclic-dimeric-GMP has been found to be responsible for the regulation of expression of many of its virulence factors with diguanylate cyclases and phosphodiesterases regulating the intracellular concentration of cyclic-di-GMP through synthesis and degradation, respectively. This study investigated the possibility that the availability of oxygen is the environmental signal crucial to the regulation of these enzymes. Prior research in our laboratory has demonstrated that the intracellular concentration of cyclic-di-GMP is elevated when exposed to anaerobic conditions. Due to this, it was hypothesized that …

Study Of The Role Of The Msaabcr Operon In Tricarboxylic Acid Cycle Activity And Persister Cell Formation In Staphylococcus Aureus, Karsen Motter

Honors Theses

Staphylococcus aureus is an important human pathogen that causes wide arrays of infections ranging from minor skin infections to lethal systemic conditions such as infective endocarditis, osteomyelitis, sepsis and pneumonia. These systemic diseases are often difficult to treat due to the presence of persister cells. Persister cells are a phenotypic variant of the bacterial population that exhibit extreme and transient antibiotic tolerance accompanied by a transient halt in growth. Upon cessation of antibiotic treatment, however, persisters resume growth which results in recurrence of infections. This characteristic of persister cells therefore displays high clinical significance. In this study, we show the …

Interregulation Between Msaabcr Operon And Ccpe To Determine Staphylococcal Metabolism And Virulence, Erin R. Cox

Honors Theses

Staphylococcus aureus is a complex human pathogen that causes problems in both healthcare and community settings. Staphylococcus aureus is a gram-positive, sphere shaped bacterium that usually colonizes in the nasal cavity of healthy individuals. Staphylococcus aureus infections are a growing health concern due to its ability to produce virulence factors, such as pigmentation, protease production, and capsule formation. Two regulators in S. aureus virulence factors are msaABCR, which is a newly characterized operon, and ccpE. In order to determine the interaction between these two regulators in regulating virulence and metabolism in S. aureus, ccpE and ccpE/ …

Phosphodiesterase D Is Involved In Bile Resistance In Listeria Monocytogenes, Sophia A. Ali

Honors Theses

Listeria monocytogenes is a deadly foodborne bacterium that is responsible for almost 20% of food-related deaths in the United States. Listeria monocytogenes contaminates ready-to-eat products such as cheese, deli meat, and ice cream. Once ingested, it invades the intestinal lining and can enter the bloodstream, causing listeriosis. There is a gap in the knowledge of the pathogenesis of L. monocytogenes in how it is able to survive in the gastrointestinal tract in the presence of bile, which has bactericidal properties. Previous studies have suggested that the second messenger cyclic-dimeric-GMP may be involved in the regulation of virulence factors of Listeria. …

Phenotypic Characterizations Of Msaabcr Operon Deletion In Staphylococcus Epidermidis Rp62a, Raelyn Williams

Honors Theses

Staphylococcus epidermidis is a human pathogen that is increasingly known for its role in hospital infections associated with implantable medical devices. Antibiotic resistance has become a concerning issue for these infections as this bacteria have various virulence traits that help to evade immune response and antibiotic treatment. Currently, the most effective way to treat S. epidermidis infection is removal of the implant and long-term antibiotic treatment. S. epidermidis causes infection by expressing several protein factors that induce biofilm formation, the bacteria’s primary virulence mechanism. The purpose of this study was to perform the phenotypic characterizations of the msaABCR operon in …

The Role Of Gac/Rsm Signal Transduction Pathway In The Biology Of Antagonistic Marine Bacterium Gynuella Sunshinyii 449, Anhthu Truong

Honors Theses

Gynuella sunshinyii is a newly characterized bacterium with a remarkable ability to produce multiple secondary metabolites that act as potential antibiotics for medical applications. Currently, little is known about gene regulation in this unusual microorganism. In 2018, studies conducted of rhizosphere microbiomes of tidal marsh grasses on Deer Island, MS, resulted in multiple isolates of halophilic, aerobic, Gram-negative bacteria with antagonistic properties. One of the most active antagonists was identified as Gynuella sunshinyii 449. The genome of strain 449 was sequenced with Illumina MiSeq, assembled with Unicycler and SPAdes, and annotated with RASTtk. The annotation revealed a 6.09 Mb genome …

A Metabolomics-Based Approach To The Screening Of Endometrial Cancer: Development Of A Gas Chromatography-Ion Trap Mass Spectrometry-Based Method, Allycia Lee

Honors Theses

Endometrial Cancer (EC) is the most common malignant tumor of the female reproductive tract. Currently there are no methods for effectively screening EC, but one method that is thought to be useful in screening EC is metabolomics. Metabolomics involves the analysis of metabolites which are low molecular weight inorganic and organic chemicals that are substrates, intermediates, and by-products of enzyme-mediated biochemical reactions in the cell. Previous research shows that the metabolic signature of EC patients are discernable from those of healthy patients. To aid in the development of an effective screening method for EC, blood serum, urine, and saliva samples …

Increasing Stress Tolerance In Saccharomyces Cerevisiae Using Lipocalin Genes, Ximena Leon

Honors Theses

Saccharomyces cerevisiae is a microorganism that is commonly used in industries, but its productivity is significantly hindered by its inability to resist high stress levels found in industrial processes. By increasing stress tolerance in S. cerevisiae, its role in industrial processes could be maximized. The objective of this study is to determine if complementation of lipocalin genes into the wildtype and knockout strains of S. cerevisiae can increase stress tolerance against a variety of stressors. We identified the knockout yeast strains, ALD3, ALD4, PDX3, and ILV1, as being sensitive to various stressors including salinity, heat, oxidative, and osmotic stresses. Arabidopsis …

Ecological, Evolutionary, And Molecular Mechanisms Driving Pyocin Diversity In Pseudomonas Aeruginosa., Aubrey A. Mojesky

Electronic Theses and Dissertations

Bacteriocins are narrow-spectrum antibiotics produced in nearly all lineages of bacteria, meaning that these antimicrobials target closely related individuals. The bacteriocins of Pseudomonas aeruginosa, called pyocins, are highly prevalent and diverse in populations of this species. Laboratory studies have shown that pyocins can function to mediate the outcome of interactions, often allowing for the coexistence of multiple strains, as no one pyocin genotype is competitively superior. Although this has been demonstrated under laboratory conditions, the function of pyocins in natural settings and the ecological, evolutionary, and genetic mechanisms underlying pyocin diversity remains unclear. As such, for my dissertation, I …

Determination Of The Biological Functions Of Undefined Domains Of Veev Nsp2., Andrew Michael Skidmore

Electronic Theses and Dissertations

Alphaviruses are positive sense, single strand, RNA viruses. These viruses occur on every populated continent. Alphaviruses are divided into two clades, the New-World and Old-World viruses. The New-World viruses include Eastern (EEEV), Western (WEEV), and Venezuelan equine encephalitis viruses (VEEV), and cause neuroinvasive disease. The Old-World viruses include Chikungunya (CHIKV) and Ross River viruses (RRV), and typically cause multijoint arthralgia. There are currently no approved antiviral therapeutics or vaccines for any alphavirus, making them a high priority for antiviral drug design and discovery. A benzamidine inhibitor (ML336) of VEEV was characterized, and determined to inhibit replication of VEEV RNA during …

Suppression Of Inflammation Of Cytokine Following Induced Francisella Tularensis Infection, Nicole Renee Setzu

Open Access Theses & Dissertations

Francisella tularensis is intracellular bacteria which is the causative agent of the disease Tularemia. Highly virulent in both humans and animals, it takes only as few as 10 microorganisms to cause a lethal infection. The bacteria can enter via direct or indirect routes causing the activations of the host innate inflammatory response to ensue. The bacteria invade host dendritic cells and neutrophils but predominately macrophages. This causes a mass inflammatory response resulting in the cytokine storm. Activation of Natural Killer T (NKT) cells has been shown to suppress inflammation in in vivo studies. Development and optimization of an in vitro …

Comparing The Incidence And Prevalence Of Oral Microbial Pathogens Selenomonas Noxia And Streptococcus Mitis Within The Unlv-Sdm Clinical Patient Population, Namgu Kim

UNLV Theses, Dissertations, Professional Papers, and Capstones

Introduction: Selenomonas noxia (SN) is a gram-negative, anaerobic bacteria, which contributes to development and progression of periodontal disease. Some evidence now suggests Streptococcus mitis (SM), a gram-positive, facultative bacterium contributing to the etiology of dental caries and periodontal disease, may also influence the prevalence of SN within subgingival complexes. Based upon the overall lack of prevalence data, the objective of this study was to evaluate presence of SN and SM using qPCR among saliva samples taken from pediatric, adult, and orthodontic dental school clinics.

Methods: This study involved a retrospective analysis of previously collected saliva samples from an existing biologic …

Genomic Analysis Of Paenibacillus Larvae Bacteriophages, Casey Stamereilers

UNLV Theses, Dissertations, Professional Papers, and Capstones

American Foulbrood is the most destructive bacterial infection of the honeybee (Apis mellifera) and is caused by the Gram-positive, spore forming bacterium Paenibacillus larvae. Current treatment methods rely on antibiotics, but antibiotics treatments are experiencing a reduction in efficacy due to the recent rise in antibiotic resistant strains of P. larvae. This has been a major catalyst for exploration of alternative treatment methods. Phage therapy is an alternative treatment method that uses viruses that exclusively infect bacteria, known as bacteriophages (phages), to combat bacterial infections. Several experimental studies have shown that phages P. larvae phages are effective at lysing P. …

Antibacterial Activity Of Pogostemon Cablin, Elizabeth Wong

Seton Hall University Dissertations and Theses (ETDs)

Patchouli (Pogostemon cablin Benth. of the mint family Lamiaceae) is a traditional Chinese medicine (TCM) plant valued for its aromatherapy, antifungal, and anti-inflammatory properties. This study examined the antibacterial effect of patchouli extract (PCE) on Grampositive Staphylococcus epidermidis (S. epidermidis) and Gram-negative Escherichia coli (E. coli) with microplate assays, CFU assays, fluorescent microscopy, molecular docking, and Omics data analysis. Microplate assay of E. coli and S. epidermidis showed that Pogostemon cablin extract (PCE) is bacteriostatic in E. coli with a MIC of 1.66 mg/ml PCE and in S. epidermidis with an MIC greater than 1.66 mg/ml PCE. Fluorescent microscopy and …

The Effect Of Egcg-P Containing Formulations On Bacillus Spp., Sabrina A. Lopez

Seton Hall University Dissertations and Theses (ETDs)

The Gram-positive Bacillus species is known for their spore-forming abilities. These spores are highly resistant to a multitude of factors such as heat, UV radiation, and chemical solvents, which can be attributed to the location of its DNA, and other components that make up the spore as a whole. Bacillus spp. can be detrimental to the food & beverage industry and the medical field due to their production of enterotoxins, which can manifest as bacterial infections. Antibiotic-resistant bacteria towards current treatments are of major concern, and thus the need for alternative therapeutic agents is urgent. The beneficial health properties of …

Sodium Pyruvate Ameliorates Influenza A Virus Infection In Vitro And In Vivo, Jessica M. Reel

Graduate Theses/Dissertations

Pyruvate is produced in duplicate at the end of glycolysis in addition to ATP and NADH. Pyruvate is the metabolite of choice in most cells, whether obtained exogenously or endogenously. Recently we found that the addition of pyruvate’s conjugate base, sodium pyruvate, to cell culture media dampened the immune response to influenza A virus (IAV) infection in cultured innate immune cells. Thus, I decided to investigate the mechanism and potential for treatment of IAV. In vitro using bone marrow derived macrophages that were infected with IAV we found that adding sodium pyruvate to the media decreased immune signaling pathways through …

Resistance Of The Freshwater Microbiome To A Combination Of Pesticides, Gabriel Hooper

Senior Honors Theses

Pesticides are used prevalently throughout the United States and can negatively affect non-target organisms. Rain run-off can move multiple pesticides into freshwater ecosystems and bring them in contact with non-target organisms that have variable tolerances to pollution. This study seeks to improve our understanding of how an acute exposure to a combination of pesticides may restructure microbial communities by examining the microbiome before and after a 48-hour exposure to 2000 ppb of herbicides (glyphosate, atrazine, and 2,4-D). Pesticide exposure did not significantly alter the alpha or beta diversity of the sample types, which demonstrates the ability of freshwater microbiomes to …

Unraveling Host-Gut Microbiota Dialogue And Its Impact On Response To Immune Checkpoint Blockade, Alexandria Cogdill

Dissertations and Theses (Open Access)

Cancer is a disease with only one degree of separation, affecting one in two men and one in three women in their lifetimes; accounting for 1 of every 6 deaths. While cancer mortality rates continue to improve, incidence rates are expected to rise and shift through 2050 due to epidemiological and demographic transitions worldwide. As such, it is imperative to continue to investigate and improve our understanding of both disease etiology and hallmarks of response to treatment. Currently, conventional therapies include, but are not limited to, surgery, chemotherapy, and radiotherapy. However, within the past decade, major advances have been made …

Implications Of The Evolutionary Past On The Activities Of Virb: A Key Transcriptional Regulator Of Virulence Genes In Shigella Flexneri, Jillian Nicole Socea

UNLV Theses, Dissertations, Professional Papers, and Capstones

Shigella species are bacterial agents that are the leading cause of diarrheal diseases, the second leading cause of child mortality worldwide. One key protein in Shigella is VirB, a transcriptional regulator of virulence genes that is essential for pathogenicity. VirB functions to antagonize H-NS, a histone-like nucleoid structuring protein that silences many genes found on the large virulence plasmid (pINV). The interplay between H-NS, the silencer, and VirB, the anti-silencer, is fundamental for Shigella virulence. Furthermore, this mechanism of gene regulation appears widespread in many bacteria including other enteric pathogens.

The goal of my dissertation was to explore the activities …

Pathogenicity Of Staphylococcus Agnetis Associated With Lame Broilers With Osteomyelitis, Sura Faris Salih Zaki

Graduate Theses and Dissertations

We developed High Resolution Melt Analysis (HERMA) as a rapid and reliable molecular diagnostic assay for the detection and identification of the main bacterial species recovered from the blood and lesions of bacterial chondronecrosis with osteomyelitis (BCO) from the lame broilers at the University of Arkansas poultry research farm. Also, the present study confirms that raising young birds on suspended wire flooring has been proved to successfully induce lameness attributable to BCO with birds being more susceptible to bacteraemia than those that were raised on litter flooring. The newly described pathogen, Staphylococcus agnetis, has been reported to be overrepresented in …

Effects On The Human Microbiome: Antibiotics And Other Chemicals, Katherine Moulton

Thinking Matters Symposium

With skin being the largest organ of the human body, there is a very large surface area for a microbiome to form and live. The human microbiome is composed of different types of bacteria, fungi, and archaea, in different locations of the body. This layer can be greatly affected by daily practices including, hygiene habits, exercise, and antibiotic uses. The major objective of this study is to identify species of the human microbiome from various body sites and test their resistance to major chemicals. To achieve this objective, the mouth, ear, axillary area, hand, belly button, and foot of several …

Bioremediation: Breaking Down The Regulations Of Genetically Modified Microorganisms, Lora Katharine Naismith

Texas A&M Law Review

Environmental bioremediation is the use of biological activity to reduce the concentration or toxicity of a pollutant. A rapidly increasing population leads to a consequential increase in industrial waste and pollution, and innovators are researching numerous techniques to degrade these pollutants and prevent their spread into the environment. These techniques are expensive and often result in secondary pollutants, which limits their widespread application. Bioremediation, however, presents a cost-friendly and more efficient way to degrade pollutants with little or no secondary pollutants. This Article explores how scientists can use genetically modified microorganisms (“GMMs”) to target specific hazardous wastes that are otherwise …

Identification Of A Chlorovirus Pbcv-1 Protein Involved In Degrading The Host Cell Wall During Virus Infection, Irina V. Agarkova, Leslie C. Lane, David D. Dunigan, Cristian F. Quispe, Garry A. Duncan, Elad Milrot, Abraham Minsky, Ahmed Esmael, Jayadri S. Ghosh, James L. Van Etten

Nebraska Center for Virology: Faculty Publications

Chloroviruses are unusual among viruses infecting eukaryotic organisms in that they must, like bacteriophages, penetrate a rigid cell wall to initiate infection. Chlorovirus PBCV-1 infects its host, Chlorella variabilis NC64A by specifically binding to and degrading the cell wall of the host at the point of contact by a virus-packaged enzyme(s). However, PBCV-1 does not use any of the five previously characterized virus-encoded polysaccharide degrading enzymes to digest the Chlorella host cell wall during virus entry because none of the enzymes are packaged in the virion. A search for another PBCV-1-encoded and virion-associated protein identified protein A561L. The fourth domain …