Microbiology Commons^™

Rates Of Evolution And Point Mutations Of Bacterial Plant Pathogens Compared To Bacterial Vertebrate Pathogens, Alejandro Cantu

Theses and Dissertations - UTB/UTPA

The relationship between a pathogen and its host is a constant interaction; as the host evolves defense mechanisms to protect itself from the pathogen, the pathogen will evolve in order to evade them. During this evolutionary process, the genomes of bacterial pathogens can change due to different selection pressures exerted by the immune system of their respective hosts. This study aimed to determine how differences in selection pressures affect the evolution of plant and vertebrate pathogens. The focus of this study was to analyze population level changes in conserved genes, as well as species level changes in the Type III …

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 …

Functional Analysis Of Cytosolic Hsp70 Nucleotide Exchange Factor Networks In Yeast, Jennifer Lynn Abrams

Dissertations and Theses (Open Access)

The Hsp70 class of molecular chaperones play critical roles in protein homeostasis via an ATP-dependent folding cycle. Cytosolic Hsp70s in the budding yeast Saccharomyces cerevisiae, Ssa and Ssb, interact with up to three distinct nucleotide exchange factors (NEFs) homologous to human counterparts; Sse1/Sse2/HSP110, Fes1/HspBP1, and Snl1/Bag1. In an effort to understand the differential functional contributions of the cytosolic NEFs to protein homeostasis (“proteostasis”), I carried out comparative genetic, biochemical and cell biological analyses. For these studies, I developed protocols to monitor protein disaggregation and reactivation in a near real-time coupled assay that revealed the importance of aggregate dynamics in the …

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 …

The Role Of Human Norovirus Surrogates, Feline Calicivirus And Murine Norovirus, On Non-Porous And Soft Porous Surfaces, Thomas Yeargin

All Theses

Human Noroviruses (HuNoV) are the leading cause of acute gastroenteritis worldwide as well as the leading cause of foodborne disease in the U.S. HuNoV can persist in the environment even after proper disinfection, making preventing HuNoV infections and controlling subsequent outbreaks extremely challenging. Epidemiological evidence suggests that soft surfaces may be a relevant source of HuNoV due to the inability to effectively decontaminate. The objectives of this study were to: 1) review the current published literature on prevalence, transmission, and disinfection pertaining to HuNoV and surrogates with an emphasis on soft surfaces as fomites, 2) optimize a recovery method capable …

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 …

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 …

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 …

Characterization Of Ftsa-Ftsn Interaction During Escherichia Coli Cell Division, [email protected] K. Busiek

Dissertations and Theses (Open Access)

Division of a bacterial cell into two equal daughter cells requires precise assembly and constriction of the division machinery, or divisome. The Escherichia coli divisome includes nearly a dozen essential cell division proteins that assemble at midcell between segregating sister chromosomes. FtsZ, a homolog of eukaryotic tubulin, is the first essential cell division protein to localize at midcell where it polymerizes into a ring-shaped scaffold (Z ring). Establishment of the Z ring is required for recruitment of downstream cell division proteins including FtsA, a cytoplasmic protein that tethers the Z ring to the inner membrane. Following localization of FtsA and …

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 …

Investigating The Impact Of Novel Iron Oxide Nanoparticles On Legionella Pneumophila Biofilms And Trophic Interactions, Brennen Jenkins

All Theses

Microbial biofilms serve as the base of food webs and are important for nutrient cycling in aquatic ecosystems. Nanoparticles (NPs) that enter into these aquatic systems have the potential to settle and become trapped within biofilms. As NPs become further integrated into consumer products, understanding their fate and effects on aquatic ecosystems is of paramount importance. Previous studies from our lab show that gold NPs induce dispersal of Legionella pneumophila biofilms. NPs with platinum and iron oxide core chemistries also lead to similar dispersal events, however, silver core NPs do not seem to induce these events due to NP aggregation. …

Poultry Performance And Food Safety Impacts Of Selected Organic Acids And Probiotics, Anita Menconi

Graduate Theses and Dissertations

Improving production parameters and controlling foodborne pathogens have been challenges to the poultry industry. Salmonella has been the most common bacterial pathogen in laboratory confirmed foodborne illness cases, and contaminated poultry and poultry products have been identified as the most important source of transmission of Salmonella to humans. Therefore, research on effective interventions to reduce Salmonella transmission at the poultry production level has gained attention. Initially, a series of studies was conducted to evaluate the use of selected organic acids in controlling foodborne pathogens and improving poultry performance. Then, the characterization and application of lactic acid bacteria and Bacillus spp. …

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 …

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 …

Genome-Wide Analysis Of The Variation In Host Genetics In Response To Experimental Challenges With Porcine Circovirus 2b, Taylor B. Engle

Department of Animal Science: Dissertations, Theses, and Student Research

Porcine circovirus is the primary causative agent responsible for inducing a group of associated diseases known as porcine circovirus associated diseases (PCVAD), which can have detrimental effects on production efficiency as well as lead to mortality. The variation in host genetics plays a role in the ability to initiate an effective immune response. The objective of this research was to identify major genetic variants and genes that influence immune response and PCVAD susceptibility. Commercial crossbred pigs (n=974) were experimentally infected with a PCV2b strain to analyze genetic sources of variation in PCVAD susceptibility. The strain used for experimental infection was …

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 …

Microbial Communities In A Coastal Cave: Cova Des Pas De Vallgornera (Mallorca, Western Mediterranean), Antoni Busquets, Joan J. Fornós, Freddy Zafra, Jorge Lalucat, Antoni Merino

International Journal of Speleology

As a part of an ongoing project on the role of microbes in the biogeochemistry of Majorcan caves, the species diversity of microbial communities present in cave pools of anchialine waters in the Cova des Pas de Vallgornera (Mallorca, western Mediterranean) is investigated by a culture-dependent method. Two-hundred and forty-eight strains isolated from this characteristic cave environment of the littoral karst are identified by whole-cell-MALDI-TOF mass spectrometry and phylogeneticaly by 16S rRNA gene sequences. Total cell counts and species diversity of the bacterial communities decreas with the distance to the entrance of the cave and to the sea. Strains are …

Structure-Based Design Of Novel Inhibitors And Ultra High Resolution Analysis Of Ctx-M Beta-Lactamase, Derek Allen Nichols

USF Tampa Graduate Theses and Dissertations

The emergence of CTX-M class-A extended-spectrum β-lactamases, which confer resistance to second and third-generation cephalosporins, poses a serious health threat to the public. CTX-M β-lactamases use a catalytic serine to hydrolyze the β-lactam ring. Specifically, the hydrolysis reaction catalyzed by CTX-M β-lactamase proceeds through a pre-covalent complex, a high-energy tetrahedral acylation intermediate, a low-energy acyl-enzyme complex, a high-energy tetrahedral deacylation intermediate after attack via a catalytic water, and lastly, the hydrolyzed β-lactam ring product which is released from the enzyme complex. The crystallographic structure of CTX-M at sub-angstrom resolution has enabled us to study enzyme catalysis as well as perform …

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 …

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

Development Of A Traveler’S Vaccine Against Dengue Infection, Arthur Lee, Dr. Bradford Berges

Journal of Undergraduate Research

There are currently no vaccines available against dengue virus. Each year, about 400 million people become infected and half a million of them, especially children, develop complications such as dengue hemorrhagic fever or dengue shock syndrome.

Genome Annotation Of Novel Viruses And Discovery Of Critical Sequences In Genes Via Comparative Analysis Of B4 Mycobacteriophage, Cameron Sargent, Dr. Sandra Burnett

Journal of Undergraduate Research

Over the past few years at Brigham Young University and other colleges nationwide, members of the Phage Hunters program have endeavored to find and analyze novel mycobacteriophage in an attempt to create new treatment and research methods for the pathogen Mycobacterium tuberculosis

Comparative Genome Analysis Of Novel Paenibacillus Larvae Bacteriophage, Bryan Merrill, Dr. Sandra Burnett

Journal of Undergraduate Research

Honey bees pollinate one third of the crops in the U.S. diet. The spore-forming bacterium Paenibacillus larvae causes American Foulbrood (AFB), a highly contagious disease that is lethal in honey bee larvae. P. larvae is the most serious pathogen affecting honey bees. The spores can be found in any healthy beehive, are stable for 40 years or more, and cannot be killed by antibiotics. The disease manifests itself when worker bees feed P. larvae spores to larvae and the spores germinate. The bacteria then consume the larvae and turns back into a spore that the worker bees then transfer throughout …

Determining Gene Expression Levels In Healthy And Degraded Alpaca Spinal Discs, Loyd Christensen, Dr. Laura C. Bridgewater

Journal of Undergraduate Research

Intervertebral Disc Degeneration (IDD) is a disease estimated to affect between 60 and 90 percent of the total population at some point in life. Evidence of spinal disc degeneration has been shown in 30 percent of individuals under 40 years old, with earliest symptoms visible at 21 years of age; its prevalence only increases with age. Symptoms of spinal disc degeneration account for more than 13 million doctor visits each year and result in costs of more than $200 billion in lost productivity and health-care related expenses in the US alone. Unfortunately, despite these staggering costs, no widely effective treatment …