Microbiology Commons^™

Functional Characterization Of The Human And Murine Schlafen Family Group Iii, Carlos A. Valenzuela

Open Access Theses & Dissertations

The Schlafen (SLFN) family of proteins are known for being encoded by interferon stimulated genes. The family is divided into three groups (I, II, III), for which the largest in size belong to the subgroup III. In humans, group III has the most members (SLFN5, SLFN11, SLFN13 and SLFN14); there is no member of group I and only one member of group II (SLFN12). All human SLFNs belonging to group III have been reported to impair viral protein expression or infection across a variety of viruses. The antiviral function is mediated in SLFN11 and SLFN13 by their tRNase activity, and …

Growth Of Purple Sulfur Bacteria Allochromatium Vinosum On Solid Phase Metal Sulfides As Sulfur And Electron Sources, Hugo Alarcon

Open Access Theses & Dissertations

Purple sulfur bacteria (PSB) are photosynthetic microorganisms known for their vital roles in geochemical cycles, especially the sulfur cycle, within anoxic photic environments. PSB are also key contributors to the nitrogen, carbon, and oxygen cycles. This study focuses on the autotrophic growth of Allochromatium vinosum, a model strain of PSB, that utilize solid-phase metal sulfides (MS) as both sulfur and electron donors. Through characterizing the growth profiles of A. vinosum on pyrite (FeS2), nickel sulfide (NiS), and iron monosulfide (FeS) nanoparticles, respectively, and investigating the bacteria-MS interaction mechanisms, this work expands our current knowledge of the metabolic capabilities and flexibility …

Biology And Ecology Of Aedes (Stegomyia) Aegypti In The Northern Chihuahuan Desert, Adam Joseph Vera

Open Access Theses & Dissertations

Aedes aegypti is a medically important mosquito species that transmits multiple arboviruses, including dengue, chikungunya, Zika, and yellow fever. This mosquito species has expanded its geographical range into expanded into the Northern Chihuahuan Desert to further increase the risk of infection by these viruses in naïve human populations. Although Ae. aegypti is abundant along the U.S.â??Mexico border, the biology and ecology of this mosquito species in this temperate/arid climate region is not understood. The objective of this study was to understand the environmental factors that influence the invasive species of Ae. aegypti abundance, breeding habitat selection, host feeding behavior, and …

Biology And Epidemiology Of Dengue Viruses In The El Paso And The Surrounding Usa And Mexico Border Communities, Pedro Miguel Palermo Infante

Open Access Theses & Dissertations

Dengue is considered one of the most important human arboviral diseases worldwide. Dengue cases have increased in the last three decades in the Americas, especially along the United States (US)- Mexico (MX) border region, where the main vector of dengue, Aedes aegypti mosquito, is widely distributed. Explosive outbreaks of dengue in northern Mexico have been associated with imported and local transmission of dengue in the US border communities, especially in the Southeast Texas area, also known as Rio Grande Valley. Due to the unknown if dengue virus (DENV) is present in other areas in the US border located west of …

Mathematical Modeling Of Potassium Modulated Viral Infection, Zaira Elizabeth Mather

Open Access Theses & Dissertations

In recent years, there is a growing interest in the investigation of using potassium to treat virus infections. In the region of infection, there is a biological observation of extracel- lular potassium level being typically very low whereas the intracellular potassium levels are much higher. There are numerous biological studies showing that elevated potassium levels in the extracellular membrane tends to block virus infections. A recent effort in this direction is a collaborative research conducted by mathematicians and biologists from the University of Texas at El Paso, New Mexico State University, and the University of New Mexico, where we develop …

Examination Of The Association Between C - Reactive Protein(Crp) And Covid-19 Infection Severity And Length Of Hospitalization, Abdulahi Aremu Ayanwale

Open Access Theses & Dissertations

Chronic stress can lead to many systemic complications and low-grade systemic inflammation including increased levels of inflammatory cytokines, such as C-reactive protein (CRP). CRP is a marker of systemic inflammation and is associated with depression and perceived stress. Elevations can result in ineffective immune responses, thereby increasing the risk of complications and mortality from infections. Recent evidence suggests that uncontrolled inflammatory responses associated with COVID 19 are a major determinant of disease severity.  The COVID 19 is transmitted from one person to another through droplets from coughing, sneezing, talking, touching droplets on surfaces and contamination by hand-to-mouth routes. The mechanism …

The Role Of Calcium Ions In Signaling And Regulation Of Efflux Pump Genes In Staphylococcus Aureus, Amy Rebecca Nava

Open Access Theses & Dissertations

Calcium ions (Ca2+) play an important role in eukaryote cell signaling and regulation of physiological functions. Although evidence of a similar role for Ca2+ in prokaryotes has been difficult to demonstrate, there is mounting evidence that Ca2+ acts as a cell regulator in bacteria. The purpose of this study was to investigate Ca2+ signaling and the effect of Ca2+ on gene expression of various multidrug resistant (MDR) efflux pumps and their regulator MgrA in Staphylococcus aureus and clinically isolated MRSA. We hypothesized that the presence of Ca2+ increased gene expression of multidrug resistance pumps, LmrS, NorA, and the regulator, MgrA. …

Molecular And Cellular Characterizations Of Glucosylceramide Transferase (Synthase) In Giardia Lamblia, Vanessa Enriquez

Open Access Theses & Dissertations

Giardiasis, caused by an intestinal protozoan, Giardia lamblia, is a major public health problem worldwide. Giardia infection is spread through the fecal-oral route via contaminated water and food. It is estimated that over 280 million people are infected with Giardia across the globe. Giardia is a non-invasive parasite and consists of a two-stage life cycle: trophozoites and cysts. Ingested cysts undergo excystation in the proximal small intestine, releasing two trophozoites (excyzoites). Upon reaching the distal small intestine and colonizing there, trophozoites transform into cysts by encystation. It has been reported earlier that the process of encystation induced the synThesis of …

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 …

Structural Characterization Of Two Large Icosahedral Dna Viruses And Their Capsid Assembly Mechanisms, Yuejiao Xian

Open Access Theses & Dissertations

In the last three decades, many large DNA viruses were discovered and grouped into a loosely defined clade of Nucleocytoplasmic Large DNA Viruses (NCLDVs). NCLDVs infect a wide range of hosts from single cellular protists to large animals. Recently, these viruses were classified as a new phylum of Nucleocytoviricota under the kingdom of Bamfordvirae. The genomes of these Nucleocytoviricota viruses (NCVs) are remarkedly large and complicated, containing many cellular genes from all three domains of life, which raised intensive debates on their evolutionary origins. Despite being classified in the same phylum, their physical structures vary and can be roughly classified …

Characterization Of The Anti-Viral Activity Of Schlafen13, Jordan Winfield

Open Access Theses & Dissertations

Schlafen13 (Slfn13) is an enzyme that belongs to the Schlafen family whose expression and function is not very well characterized. The N-terminal has a pseudo dimer structure that contains its catalytic site. There is no characterization functionally or structurally of the C-terminal of Slfn13 other than the prediction of a region with helicase activity. The objective of my Thesis was to increase our understanding of the Slfn family of proteins. Currently, Slfn13 is reported to play a role in the differentiation of monocytes and to function as an endoribonuclease that cleaves tRNA and rRNA molecules in a site-dependent sequence-independent manner. …

Serosurvey For Evidence Of Dengue And West Nile Virus Human Infections In El Paso, Texas, Veronica Suarez

Open Access Theses & Dissertations

Dengue viruses (DENV), including the 4 serotypes are the cause of dengue fever and dengue hemorrhagic fever. The viruses are transmitted by Aedes aegypti mosquitoes in urban communities in tropical, sub-tropical, and temperate regions and are the cause of the highest rate of infection and death of all known Flaviviruses. DENV are endemic in United States (US) -Mexico (MX) border communities in the Rio Grande Valley and suspected of being endemic in Ciudad Juarez, a sister city to El Paso, TX. To determine if DENV were endemic in the El Paso community, cord-blood samples from mothers were tested for antibody …

Steroid-Coa Ligases, Fadd17a1 And Fadd19a1, And Their Role In Cholesterol Side-Chain Degradation In Mycobacterium Tuberculosis, Johnathan Salim Abou-Fadel

Open Access Theses & Dissertations

Mycobacterium tuberculosis (Mtb) is a serious health issue arising from the increasing incidence of multi-drug resistant (MDR-TB) strains that are becoming more prevalent in high-risk countries, especially here in the Texas/Mexico border. Confirmed cases and outbreaks in schools and hospitals are more frequent in this region due to the high-volume pedestrian traffic between the two cities, and the lack of a modernized health system in Mexico. Identification of new Mtb metabolic pathways for development of novel antitubercular drugs is urgently needed. The goal of this current work investigates two Mtb fatty acyl-CoA ligase enzymes' (FadD17A1 and FadD19A1) to explore whether …

Novel Therapeutic Approaches For Trypanosoma Cruzi Infection, Caresse Lynn Torres

Open Access Theses & Dissertations

Trypanosoma cruzi (T. cruzi) is the causative agent of Chagas disease (ChD), an emerging illness prevalent in South and Central America. Presently, benznidazole and nifurtimox are the only two clinically available drugs against T. cruzi, which have high toxicity and limited efficacy in the chronic phase of the disease. This ailment affects 8-10 million people and has become an emerging concern in the U.S leading to an urgent need for the discovery of new treatments. Despite all efforts, there is no human vaccine available. Therapeutic vaccines are a possible option for chronic ChD in which the vaccine is used after …

Trends In Antibiotic Resistance And Correlations Of Antibiotic Use And Antibiotic Resistance In A Small Hospital In El Paso, Texas 2013-2015, Christopher Olivas

Open Access Theses & Dissertations

Antibiotic resistance is a serious public health threat, primarily, resulting from the excess and inappropriate use of antibiotics. Antibiotic resistance and antibiotic consumption trends may differ along the U.S-Mexico border from the rest of the U.S. due to geographical and cultural differences unique to the border region. The objectives of this study were: 1.) To examine the trends in antibiotic resistance among E. coli, ESBL producing E. coli, P. aeruginosa, S. aureus, and MRSA over a 3-year period (2013, 2014, 2015) in a U.S.-Mexico border area hospital; 2.) To examine the trends in antibiotic consumption among aztreonam, cefazolin, cefepime, ceftriaxone, …

Investigating The Role Of Parp-1 In Hiv-1 Replication, Sara Garcia

Open Access Theses & Dissertations

Poly (ADP-ribose) Polymerase 1 (PARP-1) is a cellular protein that that has multiple roles in the cell including DNA repair and transcription. PARP-1 has also proven by our laboratory to impair HIV-1 replication in T cells infected with HIV-1 strains entering via CD4/CXCR4. The goal of my Thesis is to increase our understanding of the mechanism implicated in the anti-HIV-1 activity of PARP-1. Initially, I focused my research in deciphering the impact of PARP-1 on the replication of HIV-1 strains entering the cell through the alternative pathway CD4/CCR5. However, technical difficulties prevented answering this question. Nevertheless, aided by the technical …

Characterizing Regulatory Factors Of The Sumoylation System, David Quintanar

Open Access Theses & Dissertations

The effects that influenzaâ??s seasonal epidemics have on human health and the global economy have been clearly noted; while they are indeed very impressive, the impact of influenza pandemics arguably surpass other known infectious agents. Influenza A virus attaches to, enters, and infect cells by releasing its segmented genome which localize to the nucleus then use the hostâ??s cellular machinery to replicate and create viral progeny. The virus is able to hijack transcriptional components as well as to interact with other known and unknown host proteins which ultimately allows for a balance between cell viability and viral propagation. One known …

Defining And Characterizing The Step In The Hiv-1 Viral Life Cycle Affected By Fullerene Derivatives, Zachary Sean Martinez

Open Access Theses & Dissertations

Fullerene derivatives, both C60 and C70, were synthesized and characterized to test their activity against HIV-1 infection. The derivatives tested have previously been reported to inhibit HIV-1 replication and/or in vitro activity of reverse transcriptase. It was found that viruses produced in the presence of low micromolar concentrations of most of these fullerene derivatives exhibit a reduction in viral infectivity greater than 99%. Quantification of virion-associated viral RNA and p24 indicates that RNA packaging and viral production were unremarkable in these viruses. These compounds did not affect infectivity of mature virions, indicating no effect on the early steps of the …

Characterizing The Role Of The Fact Complex In Hiv-1 Infection, Angelica Patricia Lopez

Open Access Theses & Dissertations

The lens epithelium-derived growth factor p75 (LEDGF/p75) is a chromatin-bound protein essential for efficient lentiviral integration. Knockdown of this protein severely affects HIV-1 integration levels and thus itâ??s replication. Genome-wide studies have located LEDGF/p75 inside actively transcribed genes where it mediates lentiviral integration. Although this is clearly established, the molecular mechanisms of LEDGF/p75 in HIV-1 infection remain in part elusive.

Using protein-protein interaction assays, we demonstrated that LEDGF/p75 complexes with a chromatin remodeling complex, Facilitates Chromatin Transcription (FACT), a heterodimer of the structure specific recognition protein 1 (SSRP1) and the human homolog of suppressor of Ty 16 (hSpt16). The FACT …

Determining The Role Of Poly [Adp-Ribose] Polymerase 1 (Parp-1) In Retroviral Infection, Luis Valdes Rodriguez

Open Access Theses & Dissertations

Possible links between PARP-1 and HIV-1 have been previously reported but the role of this protein during viral infection has remained elusive. Based on the high evolutionary conservation of PARP-1, from Drosophila to humans, we have been able to counteract the difficulties related with the functional redundancy manifested in the PARP family by studying the influence of PARP-1 on the expression of an endogenous retrovirus using the chicken B lymphoblastoid cell line DT40, this cell line exhibits low PARP-1 functional redundancy and is viable after PARP-1 knockout. We have determined that the transcription level of the endogenous retrovirus RAV-1 is …

The Characterization Of A Recombinant Virophage Integrase, Martin Christopher Chacon

Open Access Theses & Dissertations

Virophages are satellite-like dsDNA viruses that parasitize giant viruses of the family Mimiviridae. Mavirus is the second virophage discovered that associates with its host virus Cafeteria roenbergensis Virus (CroV). When co-infecting their common host cell Cafeteria roenbergensis, a marine zooplankton that is widely spread throughout the oceans, mavirus will inhibit CroV's replication. In addition, mavirus was shown to share high similarities to the Maverick/Polinton eukaryotic DNA transposons. A coding sequence in mavirus genome (MV02) reveals high homology to retroviral integrases such as those found in HIVs. The putative integrase MV02 is predicted to integrate mavirus DNA into the host genome. …

Characterization Of The Nodamura Virus Rna Dependent Rna Polymerase And Formation Of Rna Replication Complexes In Mammalian Cells, Vincent Ulysses Gant

Open Access Theses & Dissertations

Positive-strand RNA viruses amplify their genomes in membrane-bound structures associated with intracellular membranes and organelles called replication complexes (RCs). Here, we begin to elucidate mechanisms of Nodamura virus (NoV; family Nodaviridae) RC assembly. The literature reports that NoV-infected muscle tissue exhibits mitochondrial aggregation and rearrangement of mitochondrial structure, leading to disorganization of the muscle fibrils. However, the molecular basis for this pathogenesis and the role of mitochondria in NoV infection remained unclear until now. We tested the hypoThesis that NoV establishes RCs in association with mitochondria in cultured mammalian cells at physiological temperature. We used immunofluorescence confocal microscopy and biochemical …

Exploratory Study Of Seasonal Indoor Bioaerosols And The Associated Health Outcomes In Low-Income Communities In El Paso, Texas, 2014, Eric Martinez

Open Access Theses & Dissertations

Introduction: Structural degradation, moisture levels, and building failures can influence poor indoor air quality and create a good environment for bioaerosols. People spend much of their time indoors and can potentially be exposed to these bioaerosols. Several studies have correlated exposures to high concentrations of bioaerosols to various health problems, severe allergies, asthma, or other respiratory illness. Objectives: The objectives of this study are to describe bioaerosol concentrations, meteorological factors, and health outcomes during the summer and fall seasons; characterize bioaerosols (bacteria and fungi) collected in low-income communities; compare bioaerosol concentrations by season; compare meteorological factors to bioaerosol concentrations by …

The Sumoylation Of The Non-Structural Protein 1 Of The Influenza A Virus Plays A Dual Role During Viral Infection, Jason Michael Chacon

Open Access Theses & Dissertations

The potential for a highly pathogenic influenza pandemic remains a concern for global health. The ability of the influenza virus to undergo antigenic shift and genetic drift give circulating strains of influenza the high probability of developing resistance to current antiviral therapies. Emerging strains of higher virulence, to which the infected person has not had any previous exposure to viral antigens, pose a greater threat of serious illness and death. Currently, there is no antiviral therapy that is effective against all strains of influenza, emphasizing the need to develop new strategies that target cellular systems required for viral replication to …

Sumoylation Affects Ns1'S Ability To Neutralize The Interferon Response, Jeanette Cecilia Gonzalez

Open Access Theses & Dissertations

It is of huge concern the possibility that at some point in the future we may face a new pandemic involving a highly pathogenic virus due to our current preventive and treatment options to fight this viral disease. The main reason for such limitations is the ability of the virus to go over constant antigenic shifts and drifts on its viral surface proteins HA and NA. The constant mutations that affect this virus cause the need of developing new vaccines for each influenza season. Periodically, the World Health Organization (WHO) reports that around 10% of the world population gets infected …

Characterization Of Ns1 Sumoylation And Its Effect On Influenza A Viral Infection, Katherine Anne Meraz

Open Access Theses & Dissertations

Influenza virus is a contagious respiratory virus responsible for seasonal epidemics and several catastrophic pandemics in the last century. Its genome is comprised of negative sense, single-stranded RNA and, after entering the cell, it is capable of hijacking the host cellular machinery for reproducing its own genetic material. The activation of cellular defenses against influenza viral infection are triggered upon viral entry and help regulate the course of viral infection. This study focused on the interplay between the influenza A virus and the cellular SUMOylation system during viral infection. The first part of this Dissertation deals with the relevance of …

The Characterization Of The Interplay Between Sumoylation And Influenza A Virus, Andres Santos

Open Access Theses & Dissertations

Influenza A virus is a negative sense single stranded RNA virus responsible for multiple devastating pandemics in the past. This virus is capable of entering multiple eukaryotic hosts, sequestering, and using their cellular machinery for its own replicative purposes. This plethora of molecular events is all orchestrated through a shockingly limited repertoire of only 11 viral proteins. All of which are all strictly dependent on cellular processes such as post-transcriptional regulation, protein translation, post-translational modifications, etc. This study is focused on the characterization of the interplay between Influenza A virus and the cellular SUMOylation system. The first part of this …

Sumoylation Exerts Minimal Effects On The Splicing Regulatory Activity Of The Influenza A Virus Non-Structural Protein Ns1, Griselda Melendez

Open Access Theses & Dissertations

One of the greatest challenges facing the development of a universal treatment for influenza infection is the virus's ability to mutate rapidly and produce new antigenic properties. Targeting the viral components of one strain does not ensure that the treatment will be effective with a newly developed strain. One alternative would be to develop therapies that target cellular factors the virus depends on for survivability. One of these factors is the cellular SUMOylation system. We have previously demonstrated that the Small Ubiquitin-like MOdifier (SUMO) interacts with the influenza virus by SUMOylating several viral proteins and by affecting the interferon blocking …

Role Of Post-Translational Modifications In The Hiv Cofactor Activity Of Ledgf/P75, Denisse Adriana Gutierrez

Open Access Theses & Dissertations

see document.

Validation Of N-Myristoyltransferase As Potential Chemotherapeutic Target In Chagas Disease, Linda Herrera

Open Access Theses & Dissertations

The protozoan parasite Trypanosoma cruzi is the etiological agent of Chagas disease, a problem endemic to Central and South America. In recent years, this neglected infectious disease has become a global health concern. The only clinically available drugs for the chemotherapy of Chagas disease have important disadvantages such as, high toxicity, strain resistance and variable efficacy. Therefore, there is an urgent need for the development of new antichagasic agents. The enzyme N-myristoyltransferase (NMT) has been characterized in a range of eukaryotes, from Saccharomyces cerevisae to Homo sapiens. Moreover, NMT has been shown to be essential in protozoan parasites, including Leishmania …