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Articles 1 - 30 of 199
Full-Text Articles in Microbiology
Skin Of Frog And Scale Of Dragon: Nutritional Cues, Life Cycle Kinetics, And Secretome Dynamics In Batrachochytrium Dendrobatidis, Naomi C. Okada
Skin Of Frog And Scale Of Dragon: Nutritional Cues, Life Cycle Kinetics, And Secretome Dynamics In Batrachochytrium Dendrobatidis, Naomi C. Okada
UNLV Theses, Dissertations, Professional Papers, and Capstones
Nearly 50% of amphibian species are at risk of extinction, making them the most threatened group of vertebrates on the planet. A major driver of these declines is the pathogenic chytrid fungus Batrachochytrium dendrobatidis (Bd), which causes the fatal skin disease chytridiomycosis. Since its discovery in the late 1990s, Bd has been directly implicated in the extinction of 90 species of amphibians and the declines of hundreds more. Despite this devastating ecological impact, relatively little is known about its basic cellular biology.
Bd has a multi-stage asexual life cycle consisting of a motile and infectious zoospore, which encysts (into a …
Ecovoltaic Solar Energy Development Creates Novel Microclimate, Temperature, And Soil Moisture Patterns Under Solar Panels In A Warm Desert, Juan Pinos, Seth M. Munson, Claire C. Karban, Matthew D. Petrie
Ecovoltaic Solar Energy Development Creates Novel Microclimate, Temperature, And Soil Moisture Patterns Under Solar Panels In A Warm Desert, Juan Pinos, Seth M. Munson, Claire C. Karban, Matthew D. Petrie
Life Sciences Faculty Research
Background As solar energy development expands in desert regions, new installation practices and solar technologies seek to balance ecosystem conservation and energy generation (ecovoltaics). The Gemini Solar Project, a large ecovoltaic facility located in the northeastern Mojave Desert, employed low impact installation methods to reduce disturbance of the desert ecosystem within arrays of bifacial panels mounted on solar tracking systems. We evaluated microclimate and environmental conditions across five locations: four within-facility microsites (underneath solar panels, east and west panel driplines, and interspaces between panel rows) and one in the undisturbed desert outside the facility. Results Under panel microsites experienced lower …
The Role Of The Virb Ligand Ctp In The Molecular Mechanism Of Transcriptional Anti-Silencing In Shigella Flexneri, Taylor M. Gerson, Monika M A Karney, Helen Wing
The Role Of The Virb Ligand Ctp In The Molecular Mechanism Of Transcriptional Anti-Silencing In Shigella Flexneri, Taylor M. Gerson, Monika M A Karney, Helen Wing
Life Sciences Faculty Research
In bacteria, nucleoid-structuring proteins bind and constrain DNA, often leading to transcriptional silencing. In Shigella spp., the histone-like nucleoid-structuring protein H-NS silences many genes on the large virulence plasmid. Upon a shift to human body temperature, VirB, a DNA-binding protein and key transcriptional regulator of the Shigella virulence cascade, is produced. VirB counteracts H-NS-mediated transcriptional silencing and belongs to a fast-evolving clade of the ParB superfamily. Like other ParB proteins, VirB binds the ligand CTP. While CTP is essential for the anti-silencing activity of VirB, the role of CTP in the mechanism of VirB-dependent anti-silencing has yet to be …
Hot Spring Associated Infectious Diseases In The Great Basin And Southwest, Matthew Bentz
Hot Spring Associated Infectious Diseases In The Great Basin And Southwest, Matthew Bentz
UNLV Theses, Dissertations, Professional Papers, and Capstones
Like all bodies of freshwater, natural hot springs can harbor pathogenic microorganisms that carry the threat of infectious disease. The unique chemistry, increased temperature, and popularity for bathing may alter the risk profile of hot springs compared to other natural bodies of water. Despite this risk, the role of hot springs as a reservoir for infectious diseases remains understudied, particularly within the context of regional public health. Nevada and the Great Basin/Southwest have increasingly promoted hot springs for the purposes of tourism, and they share a strong link to the cultural heritage of the region. The unknown risk profile and …
The Roles Of Oprf In Pseudomonas Aeruginosa Biofilms, Erin K. Cassin
The Roles Of Oprf In Pseudomonas Aeruginosa Biofilms, Erin K. Cassin
UNLV Theses, Dissertations, Professional Papers, and Capstones
Many bacteria form multicellular communities known as biofilms. Biofilms contain bacterial cells and a protective extracellular biofilm matrix. This matrix contains exopolysaccharides, extracellular DNA (eDNA), membrane vesicles, and proteins. The matrix proteins are far less characterized than other extracellular biofilm components. In biofilms formed by the model organism Pseudomonas aeruginosa, the protein OprF is abundant in the cellular outer membrane and the extracellular matrix. In my dissertation research, I have presented data supporting the hypothesis that the OprF protein significantly affects P. aeruginosa biofilms. By examining various strain backgrounds and the nutrient-dependent effects of glucose and sodium chloride, I demonstrate …
Investigating The Influence Of Environmental Stressors To Exopolysaccharide Production In Soil Cyanobacteria: Genomic And Physiological Perspectives, Benjy Sedano-Herrera
Investigating The Influence Of Environmental Stressors To Exopolysaccharide Production In Soil Cyanobacteria: Genomic And Physiological Perspectives, Benjy Sedano-Herrera
UNLV Theses, Dissertations, Professional Papers, and Capstones
Cyanobacteria are photosynthetic microbes with essential roles in Earth’s ecosystems. The secretion of long–chain polysaccharides, known as exopolysaccharides (EPS), is a key trait facilitating cyanobacterial adaptation to diverse ecosystems. Genomics studies have shown that aquatic cyanobacteria harbor multiple gene copies encoding EPS export proteins, likely conferring a selective advantage in lakes or oceans. In addition, physiological experiments showed that nutrient limitation in aquatic habitats influences EPS production, affecting cyanobacterial fitness. However, whether terrestrial cyanobacteria also harbor multiple EPS-related genes and how nutrient limitation impacts their EPS production is not well understood.In the first chapter of my thesis, we investigated the …
Oral Prevalence Of Selenomonas Noxia Differs Among Orthodontic Patients Compared To Non-Orthodontic Controls: A Retrospective Biorepository Analysis, Kyle Hodges
UNLV Theses, Dissertations, Professional Papers, and Capstones
Introduction: The introduction of fixed orthodontic brackets in orthodontic therapy has the potential to significantly alter the oral microbial flora. Most orthodontic research has focused on cariogenic pathogens, while some evidence has demonstrated an increase in many known periodontal pathogens. However, little is known about the prevalence of the gram-negative periodontal pathogen, Selenomonas noxia (SN) among these patients.Methods: Using an existing saliva biorepository, n=208 samples from adult and pediatric orthodontic and non-orthodontic patients were identified and screened for the presence of SN using qPCR and validated primers. Results: In the pediatric study sample (n=89) 36% tested positive for the presence …
Competence Protein Comea And Oxidative Stress In Bacillus Subtilis Stationary Phase Mutagenesis, Angeline Roldan, Sam Schauf
Competence Protein Comea And Oxidative Stress In Bacillus Subtilis Stationary Phase Mutagenesis, Angeline Roldan, Sam Schauf
Undergraduate Research Symposium Posters
Stationary Phase Mutagenesis is a process where a bacterium can accumulate mutations in the absence of cell division. This may occur via competent DNA uptake and oxidant DNA damage and repair. ComEA is a transmembrane protein in B. subtilis that is required for the transport of exogenous DNA into the cell. (Figure 1)
From Resistance To Host Response: An Integrative Study Of C. Difficile Infections, Amber Consul
From Resistance To Host Response: An Integrative Study Of C. Difficile Infections, Amber Consul
UNLV Theses, Dissertations, Professional Papers, and Capstones
Clostridioides difficile infection (CDI) is a major healthcare challenge, causing severe gastrointestinal illness and significant mortality. Understanding the mechanisms of antibiotic resistance, epidemiology, and immune response in CDI is critical for developing effective treatments and prevention strategies.
This dissertation encompasses three complementary studies. The first study investigates the genetic mechanisms underlying cephalosporin resistance in C. difficile strain 630 through differential gene expression analysis. The second study provides a descriptive epidemiological analysis of C. difficile ribotypes in a Las Vegas patient population, highlighting differences between healthcare-associated (HA-CDI) and community-associated (CA-CDI) cases. The third study integrates serum analyte profiling and transcriptomic analysis …
Disruption Of The Oswrky71 Transcription Factor Gene Results In Early Rice Seed Germination Under Normal And Cold Stress Conditions, Santiago Bataller, James A. Davis, Lingkun Gu, Sophia Baca, Gaelan Chen, Azeem Majid, Anne J. Villacastin, Dylan Barth, Mira V. Han, Paul J. Rushton, Qingxi J. Shen
Disruption Of The Oswrky71 Transcription Factor Gene Results In Early Rice Seed Germination Under Normal And Cold Stress Conditions, Santiago Bataller, James A. Davis, Lingkun Gu, Sophia Baca, Gaelan Chen, Azeem Majid, Anne J. Villacastin, Dylan Barth, Mira V. Han, Paul J. Rushton, Qingxi J. Shen
Life Sciences Faculty Research
Background
Early seed germination in crops can confer a competitive advantage against weeds and reduce the time to maturation and harvest. WRKY transcription factors regulate many aspects of plant development including seed dormancy and germination. Both positive and negative regulators of seed germination have been reported in many plants such as rice and Arabidopsis. Using a transient expression system, we previously demonstrated that OsWRKY71 is a negative regulator of gibberellin (GA) signaling in aleurone cells and likely forms a “repressosome” complex with other transcriptional repressors. Hence, it has the potential to impact seed germination properties.
Results
In this study, we …
Genome-Guided Isolation Of The Hyperthermophilic Aerobe Fervidibacter Sacchari Reveals Conserved Polysaccharide Metabolism In The Armatimonadota, Nancy O. Nou, Jonathan K. Covington, Dengxun Lai, Xavier Mayali, Cale O. Seymour, Juliet Johnston, Jian-Yu Jiao, Steffen Buessecker, Damon Mosier, Alise R. Muok, Nicole Torosian, Allison M. Cook, Ariane Briegel, Tanja Woyke, Emiley Eloe-Fadrosh, Nicole Shapiro, Scott G. Bryan, Savannah Sleezer, Joshua Dimapilis, Cristina Gonzalez, Lizett Gonzalez, Marlene Noriega, Matthias Hess, Ross P. Carlson, Lan Liu, Meng-Meng Li, Zheng-Han Lian, Siqii Zhu, Fan Liu, Xian Sun, Beile Gao, Ritesh Mewalal, Miranda Harmon-Smith, Ian K. Blaby, Jan-Fang Cheng, Peter K. Weber, Gabriela Grigorean, Wen-Jun Li, Anne E. Dekas, Jennifer E. Pett-Ridge, Jeremy A. Dodsworth, Marike Palmer, Brian P. Hedlund
Genome-Guided Isolation Of The Hyperthermophilic Aerobe Fervidibacter Sacchari Reveals Conserved Polysaccharide Metabolism In The Armatimonadota, Nancy O. Nou, Jonathan K. Covington, Dengxun Lai, Xavier Mayali, Cale O. Seymour, Juliet Johnston, Jian-Yu Jiao, Steffen Buessecker, Damon Mosier, Alise R. Muok, Nicole Torosian, Allison M. Cook, Ariane Briegel, Tanja Woyke, Emiley Eloe-Fadrosh, Nicole Shapiro, Scott G. Bryan, Savannah Sleezer, Joshua Dimapilis, Cristina Gonzalez, Lizett Gonzalez, Marlene Noriega, Matthias Hess, Ross P. Carlson, Lan Liu, Meng-Meng Li, Zheng-Han Lian, Siqii Zhu, Fan Liu, Xian Sun, Beile Gao, Ritesh Mewalal, Miranda Harmon-Smith, Ian K. Blaby, Jan-Fang Cheng, Peter K. Weber, Gabriela Grigorean, Wen-Jun Li, Anne E. Dekas, Jennifer E. Pett-Ridge, Jeremy A. Dodsworth, Marike Palmer, Brian P. Hedlund
Life Sciences Faculty Research
Few aerobic hyperthermophilic microorganisms degrade polysaccharides. Here, we describe the genome-enabled enrichment and optical tweezer-based isolation of an aerobic polysaccharide-degrading hyperthermophile, Fervidibacter sacchari, previously ascribed to candidate phylum Fervidibacteria. F. sacchari uses polysaccharides and monosaccharides for growth at 65–87.5 °C and expresses 191 carbohydrate-active enzymes (CAZymes) according to RNA-Seq and proteomics, including 31 with unusual glycoside hydrolase domains (GH109, GH177, GH179). Fluorescence in-situ hybridization and nanoscale secondary ion mass spectrometry confirmed rapid assimilation of 13C-starch in spring sediments. Purified GHs were optimally active at 80–100 °C on ten different polysaccharides. Finally, we propose reassigning Fervidibacteria as a class …
Uvc And Planetary Habitability: Insights From Desert Lichens And Cyanobacteria, Tejinder Singh
Uvc And Planetary Habitability: Insights From Desert Lichens And Cyanobacteria, Tejinder Singh
UNLV Theses, Dissertations, Professional Papers, and Capstones
An important question in astrobiology is whether life can exist under the levels of UVC radiation found on Archean Earth, Mars, and exoplanets. We investigated this question by studying the UVC survival of colonial cyanobacterium and lichens that grow in harsh desert environments and possess natural sunscreens. We irradiated them nonstop in a desiccated state with a UVC flux closely representing the upper limit on those planets: 55-60 W/m². After irradiation, we rehydrated and assessed their survival using chlorophyll fluorometry and by counting the number of viable colonies that formed on agar plates. All three study organisms survived two to …
Probing The Ecological Functions Of Thermophiles Using Cultivation-Dependent And Cultivation-Independent Techniques, Dengxun Lai
Probing The Ecological Functions Of Thermophiles Using Cultivation-Dependent And Cultivation-Independent Techniques, Dengxun Lai
UNLV Theses, Dissertations, Professional Papers, and Capstones
High-temperature geothermal springs are ecosystems that resemble early Earth, offering insights into the origins and early evolution of life. In these unique ecosystems, thermophilic microorganisms thrive. However, our knowledge of thermophiles remains limited. A major challenge is that many thermophiles remain uncultivated. The primary goal of this dissertation was to explore the diversity, metabolism, and ecological functions of thermophiles using cultivation-dependent and cultivation-independent approaches. Chapter 1 provides a broad overview of geothermal spring ecosystems and thermophiles, along with a roadmap of the dissertation. Chapter 2 documents a study on the response of specific thermophiles from Gongxiaoshe (GXS) Hot Spring in …
Screening Of Orthodontic Patients And Age-Matched Non- Orthodontic Samples For High-Risk Oncogenic Human Papillomavirus (Hpv) Strains, Hunter Hinton
Screening Of Orthodontic Patients And Age-Matched Non- Orthodontic Samples For High-Risk Oncogenic Human Papillomavirus (Hpv) Strains, Hunter Hinton
UNLV Theses, Dissertations, Professional Papers, and Capstones
Introduction: The human papillomavirus (HPV) is known to cause cancer in several tissues and organs, including the cervix and the oral cavity. Several oncogenic or high-risk strains have been identified, which include HPV16 and HPV18.However, other research has demonstrated that additional oncogenic, high-risk strains exist - including HPV31, HPV33, HPV35, HPV52 and HPV58, although much less is known about their prevalence. Based upon this lack of knowledge, the primary objective of this project is to address the prevalence of these strains among pediatric and adult patients through screening of saliva samples from the UNLV-SDM and orthodontic clinic populations.
Methods: The …
Quaternary Ammonium Compound Resistance Of Klebsiella Pneumoniae And Klebsiella Quasipneumoniae Strains Isolated From The International Space Station, Natasha Svetlana Sushenko
Quaternary Ammonium Compound Resistance Of Klebsiella Pneumoniae And Klebsiella Quasipneumoniae Strains Isolated From The International Space Station, Natasha Svetlana Sushenko
UNLV Theses, Dissertations, Professional Papers, and Capstones
The International Space Station (ISS) has been continuously inhabited for twenty-three years and harbors a diverse population of microorganisms under conditions of microgravity, elevated radiation, and relative isolation, including Biosafety Level 2 (BSL-2) opportunistic pathogens. To sanitize surfaces on the ISS, astronauts use a combination of four antimicrobial quaternary ammonium compounds (QACs). As the stresses of space flight are known to stimulate virulence and antimicrobial resistance in bacteria, the frequent use of QAC disinfectants on the ISS is of concern to NASA. This not only poses risks to astronauts during future long-term space travel, but there is also a concern …
Comparison Of Molecular Methods For Absolute Quantification Of Low-Abundant Bacterial Communities In Milk, Carmina Chavez, Janet E. Williams, Michelle K. Mcguire, Mark A. Mcguire
Comparison Of Molecular Methods For Absolute Quantification Of Low-Abundant Bacterial Communities In Milk, Carmina Chavez, Janet E. Williams, Michelle K. Mcguire, Mark A. Mcguire
Undergraduate Research Symposium Posters
Milk was historically thought to be generally sterile. However, use of culture-dependent and culture-independent methods has provided strong evidence that milk has a microbiome (Figure 1). Culture-independent methods (e.g., high-throughput sequencing) have demonstrated the diversity of microbes in milk but provide relative abundance data. Culture-dependent methods have indicated microbial communities in milk are of low abundance, but it is challenging to measure absolute quantities accurately. Real-time quantitative polymerase chain reaction (RT-qPCR) has been used to quantify bacterial taxa in milk, However, concentrations often fall below the detection limit (Figure 2 & 3). Digital droplet PCR (ddPCR) allows detection of low-abundant …
Complete Genome Sequences Of Cluster F1 And Cluster B1 Mycobacterium Smegmatis Phages Karhdo And Basato, Jireh Kim, Carlos Herrera, Wai Yan Aung, Gino Pablo Gonzales Boyles, Carmina Chavez, Mona Cibulka, Emma Foley, Jose Guerra, Disha Byadarahalli Mohan Kumar, Willow Levrant, Lewis Lim, Jose Llanes, Zachary Kamuela O'Brian, Art Pagaduan, Justin Aaron Richardson, Khristian Rosales, James Schrecengost, Tommy Shin, Gabriel Strong-Lundquist, Winnie Tat, Fritz Vanderford, Isabelle Vrinceanu, Vicky Wang, Stephanie Yang, Christy Strong, Philippos K. Tsourkas, Kurt Regner
Complete Genome Sequences Of Cluster F1 And Cluster B1 Mycobacterium Smegmatis Phages Karhdo And Basato, Jireh Kim, Carlos Herrera, Wai Yan Aung, Gino Pablo Gonzales Boyles, Carmina Chavez, Mona Cibulka, Emma Foley, Jose Guerra, Disha Byadarahalli Mohan Kumar, Willow Levrant, Lewis Lim, Jose Llanes, Zachary Kamuela O'Brian, Art Pagaduan, Justin Aaron Richardson, Khristian Rosales, James Schrecengost, Tommy Shin, Gabriel Strong-Lundquist, Winnie Tat, Fritz Vanderford, Isabelle Vrinceanu, Vicky Wang, Stephanie Yang, Christy Strong, Philippos K. Tsourkas, Kurt Regner
Life Sciences Faculty Research
We present the complete genome sequences of Mycobacterium smegmatis phages Karhdo and Basato, isolated in Clark County, Nevada. The phages were isolated and annotated by students enrolled in undergraduate research courses over two semesters at the University of Nevada, Las Vegas.
Biochemical Characterization Of Fsa1572 From Fervidibacter Sacchari, The First Hyperthermophilic Gh50 With Β-1, 4-Glucanase Activity, Jonathan Covington
Biochemical Characterization Of Fsa1572 From Fervidibacter Sacchari, The First Hyperthermophilic Gh50 With Β-1, 4-Glucanase Activity, Jonathan Covington
UNLV Theses, Dissertations, Professional Papers, and Capstones
The bacterium Fervidibacter sacchari is an aerobic hyperthermophile that catabolizes various polysaccharides and is the only cultivated member of the class Fervidibacteria within the phylum Armatimonadota. Among its glycoside hydrolase (GH) cache is an enzyme from GH family 50 (GH50), an understudied family with only 25 characterized representatives and two known activities from 1,518 predicted members in the Carbohydrate-Active EnZyme (CAZy) Database. Here, we expressed, purified, and functionally characterized an extracellular GH50 from F. sacchari called Fsa1572. Using colorimetric assays, we show it has novel β-1,4-glucanase activity and only weak agarose activity that is typical for GH50 enzymes. The purified …
Poop! There It Is! Anti-Germinants And Biological Variables As Modulators Of Clostridioides Difficile Infection (Cdi), Jacqueline Renee Phan
Poop! There It Is! Anti-Germinants And Biological Variables As Modulators Of Clostridioides Difficile Infection (Cdi), Jacqueline Renee Phan
UNLV Theses, Dissertations, Professional Papers, and Capstones
Clostridioides difficile infection (CDI) is a major cause of antibiotic-associated diarrhea. Due to its insidious nature, the Centers for Disease Control and Prevention (CDC) has declared CDI an urgent threat. A key characteristic of C. difficile is its ability to form dormant spores that act as the infectious vehicles for disease. In the gut, spores recognize bile salts to germinate into toxin-producing cells.Dysbiosis of the gut microbiome is a key factor in allowing the C. difficile spores to germinate. Normal gut microbiota naturally protects from CDI. However, biological variables such as diet and sex have been found to modulate to …
Desert Spring Prokaryotes And Benthic Macroinvertebrates: Geological And Ecological Controls, Ariel D. Friel
Desert Spring Prokaryotes And Benthic Macroinvertebrates: Geological And Ecological Controls, Ariel D. Friel
UNLV Theses, Dissertations, Professional Papers, and Capstones
Desert springs are aquatic oases, being considered among the most diverse and imperiled ecosystems on Earth. Despite the ecological significance and threatened status of desert springs, few studies have surveyed the microorganisms in these systems or their interactions with other community members. The primary goal of this dissertation was to describe the major controls influencing the community ecology of prokaryotic and BMI communities in cold- and moderate-temperature desert springs of the southern hydrographic Great Basin. Chapter 1 provides a broad overview of spring ecosystems and of each chapter included in this dissertation. Chapter 2 documents the first-ever, regional-scale survey of …
Effects Of Cations And Dipicolinic Acid On B. Anthracis Spore Physiology And Cytotoxicity, Chandler P. Hassan
Effects Of Cations And Dipicolinic Acid On B. Anthracis Spore Physiology And Cytotoxicity, Chandler P. Hassan
UNLV Theses, Dissertations, Professional Papers, and Capstones
Inhalation of Bacillus anthracis spores leads to the most severe form of anthrax. Following phagocytosis by alveolar macrophages, spores germinate inside the phagolysosome. The mechanism used by the newly germinated B. anthracis cells to survive within macrophages is not completely understood.B. anthracis spores contain large concentrations of calcium in complex with dipicolinic acid (Ca-DPA). Upon germination, the cell excretes the large depot of Ca-DPA. DPA is an amphipathic molecule that could act as a buffer and modulate phagolysosome acidification. Intracellular calcium overload can disrupt signaling pathways required for normal macrophage function and trigger cell death. We hypothesized the release of …
Oral Prevalence Of Akkermancia Muciniphila Among Pediatric And Adult Orthodontic And Non-Orthodontic Patients, Ching Shen
UNLV Theses, Dissertations, Professional Papers, and Capstones
Akkermansia muciniphila (AM) is one of many highly abundant intestinal microbes that influences homeostasis and metabolic disorders and may also play a role in oral disorders. However, there is little evidence regarding the oral prevalence of this organism. Based upon this lack of evidence, the primary goal of this project is to survey an existing saliva repository to determine the overall prevalence of this organism and any associations with demographic or patient characteristics (age, sex, body mass index, race/ethnicity, orthodontic therapy). Using an approved protocol, a total n = 141 pediatric samples from an existing saliva repository were screened using …
Long-Range Regulation By The Shigella Virulence Gene Regulator, Virb, Cody Cris
Long-Range Regulation By The Shigella Virulence Gene Regulator, Virb, Cody Cris
UNLV Theses, Dissertations, Professional Papers, and Capstones
Nucleoid-structuring proteins (NSPs) in bacterial cells can exert gene regulatory effects over great distances on DNA. This contrasts with the traditional view of bacterial transcriptional regulation, where transcription factors bind cis-acting regulatory sites proximal (<250 bp) to promoters to influence gene expression. In Shigella species, the histone-like nucleoid-structuring protein (H-NS) transcriptionally silences many genes on the large (~220 kb) virulence plasmid. During host colonization, however, silencing by H-NS is alleviated by the anti-silencer protein, VirB, which remodels the H-NS:DNA complex. This transcriptional anti-silencing is mediated by VirB:DNA interactions and the modulation of DNA supercoiling, which lead to the up-regulation of virulence genes. VirB is a central regulator of Shigella virulence, but the mechanistic basis for transcriptional regulation is incompletely characterized. Here, I focus on the potential for VirB to regulate transcription from remotely located DNA binding sites. Employing complementary in vivo approaches, I assessed the spatial stringency of the VirB binding site and elucidated how varying cellular VirB levels impacts regulation over different distances. I also evaluated how a molecular roadblock on DNA influences remote regulation by VirB. Additionally, I developed control tools to validate the ability of VirB to spread along DNA, an activity of VirB that putatively drives transcriptional regulation. These data are consistent with transcriptional anti-silencing being driven by VirB spreading along DNA. Overall, these findings highlight how VirB is not a conventional transcriptional regulator and broaden our perspective on transcriptional control in bacteria. Furthermore, this work contributes to our understanding of long-range gene regulatory effects, which are frequently overlooked and poorly characterized in bacteria.
Predicting The Next Pandemic: Utilizing Wastewater-Based Epidemiology As A Novel Technique For Detecting Mpox Dna, Austin Tang, Michael Moshi, Hayley Baker, Ching-Lan Chang
Predicting The Next Pandemic: Utilizing Wastewater-Based Epidemiology As A Novel Technique For Detecting Mpox Dna, Austin Tang, Michael Moshi, Hayley Baker, Ching-Lan Chang
Undergraduate Research Symposium Lightning Talks
Mpox cases are trending downward in Las Vegas, aligning with national trends. The study demonstrates that it is possible to extract mpox DNA directly from wastewater and quantify the genetic material using qPCR. This research indicates that WBE can be utilized to give a relative abundance of virual nucleic acids in wastewater, giving opportunities for early-warning systems and other public health interventions. Mpox remains a global threat to public health, continued surveillance of MPXV using wastewater is necessary to ensure that we can detect unusual spike in viral DNA level. Mpox detected in the wastewater samples will be sequences to …
Quantification Of Sars-Cov-2 Prevalence Using Wastewater Surveillance, Moonis Ghani, Hayley Baker, Nabih Ghani, Anthony Harrington, Ching-Lan Chang
Quantification Of Sars-Cov-2 Prevalence Using Wastewater Surveillance, Moonis Ghani, Hayley Baker, Nabih Ghani, Anthony Harrington, Ching-Lan Chang
Undergraduate Research Symposium Lightning Talks
SARS-CoV-2 RNA was successfully detected in the wastewater samples. PMMoV concentrations varied little, meaning it was a valid control. The diversity of SARS-CoV-2 concentrations indicated varying levels of infection within different parts of the community. PCR and WGS can help determine viral load and identify variants.
Calcite Spherulite Formations And Their Controls In Halophilic Bacterial Cultures, Zakaria Jibrin
Calcite Spherulite Formations And Their Controls In Halophilic Bacterial Cultures, Zakaria Jibrin
UNLV Theses, Dissertations, Professional Papers, and Capstones
This study arose from an accidental discovery of calcite spherulites forming on colonies of various halophilic bacteria grown on solid Luria-Bertani medium made containing water from a brine pool in Death Valley, their natural habitat. Further studies with a large spherulite forming bacteria, Pseudoalteromonas haloplanktis, showed that calcite precipitation conditions were the consequence of bacteria using amino acids as a source of carbon and energy, a metabolism that produces NH3 and CO2 waste products. NH3 raises the pH of the medium, turning CO2 into CO32-. Calcium in the natural brine combines with CO32-. The resulting spherulitic calcite precipitation is nano-acicular …
Taxonomic And Physiological Insights Into Novel Bacterial Class Fervidibacteria, Nancy Nou
Taxonomic And Physiological Insights Into Novel Bacterial Class Fervidibacteria, Nancy Nou
UNLV Theses, Dissertations, Professional Papers, and Capstones
Recent studies incorporating cultivation-independent techniques to assess microbial communities, namely metagenomics and single-cell genomics, have pushed the proposed number of bacterial phyla from less than 50 to over 100. One such lineage is the candidate bacterial phylum Fervidibacteria, a strictly thermophilic group that has been identified in terrestrial geothermal springs in North America, Asia, and Antarctica through DNA sequencing. By analyzing 62 medium- and high-quality genomes and through cultivation-dependent experiments, this study serves to set up taxonomy and describe physiology within the taxon. Over the course of this study, we propose Candidatus Fervidibacteria should be reclassified as novel class Fervidibacteria …
Describing Bacterial Mutagenic Hotspots And Signatures Along With The Factors That Drive Them, Carmen Vallin
Describing Bacterial Mutagenic Hotspots And Signatures Along With The Factors That Drive Them, Carmen Vallin
UNLV Theses, Dissertations, Professional Papers, and Capstones
In my dissertation work, I investigated bacterial mutagenesis. I asked: where do mutations occur in the bacterial genome? What types of mutations occur? What factors promote or prevent mutations? And lastly, how do the answers to these questions change depending on the bacterial life cycle (When)? I used Bacillus subtilis, a Gram-positive bacterium belonging to the phylum Firmicutes, and Escherichia coli, a Gram-negative bacterium belonging to the phylum Proteobacteria, to answer these questions. B. subtilis and E. coli are model systems that have been used to gain insights into fundamental processes of mutations and evolution for nearly ~8 decades. Here, …
Microbial Contamination On Ambulance Surfaces: A Systematic Literature Review, Adam Obenza, Patricia Cruz, Mark Buttner, D. Woodard
Microbial Contamination On Ambulance Surfaces: A Systematic Literature Review, Adam Obenza, Patricia Cruz, Mark Buttner, D. Woodard
Environmental & Global Health Faculty Research
Healthcare-associated infections (HAIs) are infections that patients acquire while receiving medical treatment in a healthcare facility. During ambulatory transport, the patient may be exposed to pathogens transmitted from emergency medical service (EMS) personnel or EMS surfaces. The aim of this study was to determine whether organisms commonly associated with HAIs have been detected on surfaces in the patient-care compartment of ambulances. Five electronic databases – PubMed, Scopus, Web of Science, Embase and Google Scholar were used to search for articles using inclusion and exclusion criteria following the PRISMA checklist. Inclusion criteria consisted of articles published in English, between 2009 and …
Phage Commander, An Application For Rapid Gene Identification In Bacteriophage Genomes Using Multiple Programs, Matt Lazeriff, Geordie Ryder, Sarah L. Harris, Philippos K. Tsourkas
Phage Commander, An Application For Rapid Gene Identification In Bacteriophage Genomes Using Multiple Programs, Matt Lazeriff, Geordie Ryder, Sarah L. Harris, Philippos K. Tsourkas
Computer Science Faculty Research
The number of sequenced bacteriophage genomes is growing at an exponential rate. The majority of sequenced bacteriophage genomes are annotated by one or more of several freely available gene identification programs (Glimmer, GeneMark, RAST, Prodigal, etc.). No program has been shown to consistently outperform the others; thus, the choice of which program to use is not obvious. We present the Phage Commander application for rapid identification of bacteriophage genes using multiple gene identification programs. Phage Commander runs a bacteriophage genome sequence through nine gene identification programs (and an additional program for identification of tRNAs) and integrates the results within a …