Microbiology Commons^™

Regulation Of The Candida Albicans Arginine Biosynthetic Pathway, Claudia Jimenez Lopez

Dissertations and Theses (Open Access)

Candida albicans is the most importan thuman-associatedfungus.It is a commensal microorganism but also an opportunistic pathogen able to cause superficial infections aswellaslife-threateninginfectionswhich are associated with a highmortalityrateof 50%. The interactions between C. albicans and the cells of the mammalian innate immune system, which confer the most important protecting mechanisms against disseminated infections, are very dynamic and determine the success of C. albicans as a pathogen. Transcriptional profiling has shown that phagocytosis of C. albicans by macrophages results primarily in the activation of alternative carbon metabolism pathways suggesting that the pathogen is exposed to a glucose poor environment. Changes in …

Functional Implications Of The Baf–B1 Axis During The Vaccinia Virus Life Cycle, Nouhou Ibrahim

School of Biological Sciences: Dissertations, Theses, and Student Research

Vaccinia virus is the prototypic member of the Poxviridae family, which includes variola virus, the agent of smallpox. Poxviruses encode their own transcriptional machinery and a set of proteins to evade the host defense system, and thus are able to replicate entirely in the cytoplasm of their host. The poxvirus life cycle occurs in sequential stages: early gene expression, DNA replication, intermediate gene expression and then late gene expression and morphogenesis. The temporally staged poxvirus life cycle makes viral DNA replication a required event for post-replicative events to occur. However, viral DNA replication itself depends on an early viral Ser/Thr …

Clpxp Modulates Cell Growth And Morphology In Cell Shape Mutants Of E.Coli, Ryann Murphy

Senior Honors Projects

ClpXP modulates cell growth and morphology in cell shape mutants of E. coli

Ryann Murphy¹ and Jodi L. Camberg¹

¹University of Rhode Island, Department of Cell and Molecular Biology, Kingston, RI, 02881

Penicillin Binding Proteins (PBPs) are a family of prokaryotic membrane proteins named for their propensity to bind the antibiotic penicillin and are involved in remodeling and deposition of peptidoglycan. In wild type Escherichia coli cells, the uniform rod shape is conserved across generations. E.coli cells containing multiple deletions of Low Molecular Weight (LMW) PBPs exhibit irregular shapes. LMW PBP5 (dacA) is a potential …

Population Dynamics Of Triticum Mosaic Virus In Various Host Species, Melissa S. Bartels

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

It has been established that RNA viruses should be genetically diverse, due to the high error rate of their RNA-dependent RNA polymerases and the lack of proof-reading capabilities. Plant RNA viruses are not as genetically diverse as expected. Evolutionary factors, such as purifying selection and bottlenecks that favor genetic stability, might be affecting plant viral populations. Otherwise RNA virus populations, with their potential for extreme diversity, might acquire a lethal number of mutations leading to the collapse of the population.

Triticum mosaic virus (TriMV) populations maintained in a controlled greenhouse environment displayed genetic stability. The mutation frequency per nucleotide of …

Isolation And Characterization Of Paenibacillus Larvae Bacteriophages For Use As A Treatment Of American Foulbrood Disease In Honeybees, Diane Gerda Yost

UNLV Theses, Dissertations, Professional Papers, and Capstones

American foulbrood disease is a destructive honeybee illness cause by the bacterial pathogen, Paenibacillus larvae. Current methods of treatment are either destructive or do not completely eradicate the infection, and as such, undertaking further research to determine the effectiveness of alternate treatment methods is of consequence.

The therapeutic use of bacteriophage that are capable of lysing host bacterial cells, or phage therapy, is one such potential treatment. Phage are viruses that infect bacteria, and are generally very host-specific. As such, targeting a pathogen would require obtaining phage specific for P. larvae. Therefore, obtaining P. larvae phage requires screening environmental samples …

Determining The Presence Of Carbapenem Antibiotic Resistance In Clinical Isolates, Fidelis Uzoma Enyinnaya

UNLV Theses, Dissertations, Professional Papers, and Capstones

Carbapenems are β-lactam antibiotics reserved for the treatment of severe microbial infections, especially those targeting the Enterobacteriaceae. Introduced in the 1980s, carbapenems have been used successfully in hospitals, and in the 1990s resistance was discovered. Carbapenem resistance is conferred through the production of carbapenemases. In the U.S., the most common carbapenemase is Klebsiella pneumoniae carbapenemase (KPC). In 2012, the National Healthcare Safety Network reported a carbapenem resistance rate of 13.0% among Klebsiella pneumoniae infections, and indicated that the mortality rate associated with carbapenem resistant Enterobacteriaceae (CRE) infections ranged from 48.0-71.9%. According to the Food and Drug Administration (FDA), carbapenem resistance …

Development Of A Molecular Method For Detecting The Causative Agent Of Swimmer's Itch (Trichobilharzia) In Freshwater Ecosystems, Heidi Mcmaster

UNLV Theses, Dissertations, Professional Papers, and Capstones

Cercarial dermatitis, commonly known as swimmer's itch, is caused by penetration of larvae of the schistosome,Trichobilharzia, into the dermis and epidermis layers of the skin. Symptoms are characterized by painful swelling and itching at the site of penetration. The normal hosts for the life cycle of the schistosome are aquatic birds and aquatic snails. The most frequently used method of detection forTrichobilharziais microscopy. With increases in the occurrence of cercarial dermatitis outbreaks in freshwater in the Southwestern United States, it is becoming increasingly important to develop and standardize a molecular method for rapid detection that can assist health professionals and …

Sa-4-1bbl As A Platform To Develop Adjuvant Systems For Prophylactic And Therapeutic Vaccines., Gunes Dinc 1984-

Electronic Theses and Dissertations

Vaccines against infectious diseases are one of the most critical accomplishments in modern medicine. Despite significant progress in vaccinology, there is still a dire need for developing vaccines against various acute and chronic infections and cancer. In general, vaccines are categorized as prophylactic, given to healthy individuals to prevent disease, and therapeutic, administered to people who already have disease. As such, the nature, quality, and quantity of immune responses required for the efficacy of these two types vaccines are different. Prophylactic vaccines against infectious diseases primarily rely on the generation of neutralizing high titers of antibody for their efficacy. These …

Regulation Of Macrophage Inflammatory Signaling Pathways By Amp-Activated Protein Kinase., Yanfang Zhu

Electronic Theses and Dissertations

AMP-activated protein kinase, AMPK, is a conserved serine/threonine kinase with a critical function in the regulation of metabolic pathways in eukaryotic cells. Recently, AMPK has been shown to play an additional role as a regulator of inflammatory activity in leukocytes. Treatment of macrophages with chemical AMPK activators, or forced expression of a constitutively active form of AMPK, results in polarization to an antiinflammatory phenotype. Additionally, we reported previously that stimulation of macrophages with antiinflammatory cytokines such as IL-10, IL-4 and TGF-ß results in rapid activation of AMPK, suggesting that AMPK contributes to the suppressive function of these cytokines. In the …

Fruiting Bodies Of The Social Amoeba Dictyostelium Discoideum Increase Spore Transport By Drosophila, Jeff Smith, David C. Queller, Joan E. Strassmann

Biology Faculty Research

Background: Many microbial phenotypes are the product of cooperative interactions among cells, but their putative fitness benefits are often not well understood. In the cellular slime mold Dictyostelium discoideum , unicellular amoebae aggregate when starved and form multicellular fruiting bodies in which stress-resistant spores are held aloft by dead stalk cells. Fruiting bodies are thought to be adaptations for dispersing spores to new feeding sites, but this has not been directly tested. Here we experimentally test whether fruiting bodies increase the rate at which spores are acquired by passing invertebrates.
Results: Drosophila melanogaster accumulate spores on their surfaces more quickly …

Study Of The Function Of The Mold Specific Gene Ms95 In Dna Repair In The Pathogenic, Dimorphic Fungus Histoplasma Capsulatum, Erin M. Smith

Honors Theses

Histoplasma capsulatum (Hc) is a dimorphic fungus that is the etiologic agent of the respiratory infection Histoplasmosis that is mediated by a shift from the mold phase to the pathogenic yeast phase. Genes have been identified that are specific to the mold or yeast phase in order to study the molecular biology of this shift. MS95 was identified in a subtractive cDNA library that was enriched for mold-specific genes, and has been found to be homologous to the DNA damage-responsive gene DDR48, which functions in DNA repair in Saccharomyces cerevisiae. In order to elucidate the function of MS95, a …

Comparing Virus Ultrafiltration Of Bacteriophages With Filtration Of Minute Virus Of Mice, Kent Smith

Graduate Theses and Dissertations

Industrial production of protein therapeutics demand rigorous testing and clearance of viruses. The U.S. Food and Drug Administration dictate the purity of pharmaceuticals with regards to viral contamination. As this testing is time consuming and expensive using mammalian cells and viruses, bacteriophages may provide a faster and cheaper alternative for membrane filtration processes. We used ultrafiltration membranes to filter protein solutions with viruses. Two bacteriophages were tested against membranes with two different pore sizes. These membranes were then tested by inverting the membrane's orientation. Flux measurements and log virus removal data were taken. Flux and log virus removal were seen …

Characterization Of Tonb In Rhizobium Leguminosarum Atcc 14479, Brian D. Hill

Electronic Theses and Dissertations

Rhizobium leguminosarum is a gram-negative soil bacterium that requires iron for survival. However, iron becomes insoluble in the presence of oxygen at physiological pH. In response, Rhizobia species have used siderophore mediated iron transport systems to meet their iron requirements. R. leguminosarum ATCC 14479 produces the trihydroxymate siderophore vicibactin and we hypothesize that the import of the ferric iron-vicibactin complex is energized by the TonB-ExbB-ExbD system. Here, we have identified a putative tonB gene. A tonB mutant was created and compared with wild type in its ability to transport ⁵⁵Fe-vicibactin. Also, the putative TonB of R. leguminosarum ATCC …

Combined Metagenomic And Phenomic Approaches Identify A Novel Salt Tolerance Gene From The Human Gut Microbiome, Eamon Culligan, Julian R. Marchesi, Colin Hill, Roy D. Sleator

Department of Biological Sciences Publications

In the current study, a number of salt-tolerant clones previously isolated from a human gut metagenomic library were screened using Phenotype MicroArray (PM) technology to assess their functional capacity. PM's can be used to study gene function, pathogenicity, metabolic capacity and identify drug targets using a series of specialized microtitre plate assays, where each well of the microtitre plate contains a different set of conditions and tests a different phenotype. Cellular respiration is monitored colorimetrically by the reduction of a tetrazolium dye. One clone, SMG 9, was found to be positive for utilization/transport of L-carnitine (a well-characterized osmoprotectant) in the …

Knockout Nbmp2 Mouse Embryonic Fibroblast Cell Line, Josh Yates, Dr. Laura Bridgewater

Journal of Undergraduate Research

Bone morphogenetic proteins (BMPs) contribute to many different aspects of development including mesoderm formation, heart development, neurogenesis, skeletal development, and axis formation. They have previously been recognized only as secreted growth factors. Recently, researchers in the Bridgewater lab discovered a nuclear variant of Bone Morphogenic Protein 2 (nBMP2). To better understand the function of nBMP2, our lab generated a mutant mouse line in which nBMP2 is missing from the nucleus. These mice display learning and memory deficits, muscle dysfunction, and abnormal immune responses. In order to validate the mouse model and to study the molecular mechanisms of nBMP2 we have …

Inhibition Of Epstein-Barr Virus Infection By Kalanchoe Pinnata Extract, Lance A. Stutz, Dr. Brian Poole

Journal of Undergraduate Research

Epstein-Barr virus (EBV) is a common infectious agent which infects more than 95% of adults worldwide (1). EBV is related to a number of diseases, including cancers such as Burkitt’s lymphoma and nasopharyngeal carcinoma, and is the causative agent of infectious mononucleosis (2). Upon infection, EBV invades antibody-producing immune cells known as B cells. Most people do not show signs or symptoms of the infection because EBV tends to hide in B cells in a latent state. Latent EBV infection contributes to the development of EBV-associated cancers. However, EBV can also be in an active or lytic state. In this …

Ebi2 Expression In Different Latency Stages And Primary B Cells, Jillian Markham, Dr. Brian Poole

Journal of Undergraduate Research

Epstein-­‐Barr Virus (EBV) causes infectious mononucleosis upon primary infection, commonly known as “mono.” Less commonly known is that EBV doesn’t get eradicated from your body after you recover from mono. EBV quietly occupies a small portion of B cells in 90% of human adults [1]. Besides mononucleosis, EBV infection is linked to cancers, lymphomas, and several autoimmune diseases [2.3].

The Effects Of Dna Methylation On Nucleosome Positioning, Marcus Vranes, Dr. Steven Johnson

Journal of Undergraduate Research

Recent studies have attempted to discover the correlation that exists between DNA methylation and nucleosome positioning, but none have explored the direct effect of DNA methylation on nucleosome formation and positioning. This research is directly testing the effects of DNA methylation on nucleosome positioning, and whether the histone octamer has preferred sequences to which it binds, which will add to our understanding of gene expression and regulation. A better understanding of these concepts will help to aid efforts in gene therapy to improve the quality of life for many people who suffer from various genetic conditions.

Biofilm Regulation In Yersinia Pseudotuberculosis Through Elements Downstream Of The Bara/Uvry Two-Component System, Jeffrey Schachterle, Dr. David Erickson

Journal of Undergraduate Research

The bacteria Yersinia pestis is the causative agent of bubonic plague, and its ability to form biofilm in fleas is essential for plague transmission by fleas [1]. Y. pestis recently evolved from Y. pseudotuberculosis (Y. pstb), and the two have nearly identical genomes. Y. pestis forms a biofilm in fleas that is capable of blocking the flea’s feeding. These biofilms are made up of bacteria stuck to a polysaccharide matrix that is made by the hmsHFRS gene products. Y. pstb is capable of infecting fleas, but will block the flea’s feeding [1]. Since the hmsHFRS genes themselves are identical, this …

Detecting Endogenous Ccl28, Sara Mason, Dr. Eric Wilson

Journal of Undergraduate Research

Chemokines play a well-characterized and significant role in the immune system as chemoattractants for white blood cells. Some chemokines have also been shown to have antimicrobial properties in addition to their chemoattractant functions. CCL28 is a chemokine that aids in the recruitment of antibody secreting cells to mucosal surfaces of the body, especially in the large intestine and lactating mammary glands.1 Recent research has shown that, in addition to recruiting lymphocytes, CCL28 also exhibits antimicrobial activity against gram positive and gram negative bacteria, and antifungal activity.2