Microbiology Commons^™

Impact Of Wheat Streak Mosaic Virus And Triticum Mosaic Virus On Transmission By Aceria Tosichella Keifer (Eriophyidae) And Virus Epidemiology In Wheat, Camila F. De Oliveira

Department of Entomology: Dissertations, Theses, and Student Research

The wheat curl mite (WCM), Aceria tosichella Keifer, transmits a complex of viruses, Wheat streak mosaic virus (WSMV), Triticum mosaic virus (TriMV) and Wheat mosaic virus (WMoV), to wheat, Triticum aestivum, in the Great Plains. Co-infection of wheat by these viruses is frequently observed, increasing disease severity and yield loss.

Current genetic work classifies WCM populations into two genotypes, Type 1 and Type 2. It has been shown that different mite genotypes are able to transmit viruses at varying rates. WCM-virus relations are very specific and can impact vector biology. In this study, the primary objective was to determine …

Proximity-Labeling Of Near Neighbors Of Lamin A And Lamin A-Δ50 (Progerin)., Mohammad Sabri

Undergraduate Honors Theses

In an attempt to isolate and identify proteins that differentially interact with or locate near lamin A and progerin, we used a previously described method named BioID (proximity-dependent biotin identification). This method is based on fusion of a promiscuous E. coli biotin-protein ligase (BL) to a targeting protein (in this study, lamin A-GFP and progerin-GFP). The biotin ligase biotinylates amino residues in proteins that are near-neighbors of the fusion protein. To create the fusion proteins, BL was sub-cloned from a pcDNA3.1 MCS-BirA(R118G)-HA plasmid donated by Kyle Roux from University of South Dakota. The BL fragment was ligated into a pNEBR-X1-lamin …

Identification And Characterization Of Genetic Factors Involved In Candida-Bacterial Interactions, Sean J. Fox

Electronic Theses and Dissertations

Throughout existence, fungi and bacteria have long shared ecological niches and thus engage in numerous interactions to mutually enhance survival or antagonistically gain competitive advantages. Of importance to human health are those interactions that involve bacteria with the opportunistic fungi, Candida albicans. An important virulence factor of C. albicans is the ability to control morphology, which allows the transition between yeast, pseudohyphal, and hyphal phenotypes. Morphological control in C. albicans is governed by quorum sensing and the secreted autoregulatory molecule farnesol. Quorum sensing allows individual cells to sense the environment and respond as a group. Bacteria also use quorum …

The Influence Of Hydrogeomorphology, Soil Redox Conditions, And Salinity On The Spatial Zoning Of Saltgrass, Salt Rush, And Cattails In Scotts Creek Marsh, Swanton Pacific Ranch, Ca, Mark D. Gormley

Master's Theses

Scotts Creek Marsh (SCM) is a small coastal wetland ecosystem in Davenport, CA. The vegetation of SCM is dominated by three halophytic zones comprised of saltgrass, salt rush, cattails. The objectives of the study were (i) to investigate the variables that influence the zoning of the three dominant halophyte communities in SCM and (ii) to the test the effectiveness of Indicator of Reduction in Soil (IRIS) tubes to indicate the reduction of S. The study examined the following parameters from April 6 to July 21, 2013: (i) the HGM of Scotts Creek Marsh, (ii) soil oxidation and reduction (redox) conditions, …

Characterization Of The Role(S) Of Env Protein Of Human Endogenous Retrovirus-K In Multiple Human Cancers, Ming Li

Dissertations and Theses (Open Access)

Human endogenous retroviruses (HERVs) are remnants from ancient retroviral infections, and most of them are inactive in normal tissues. One family of HERV, HERV-K, is found to be associated with multiple human cancers including breast cancer, pancreatic cancer and melanoma, but the causal relationship between HERV-K and cancer is still unclear. Increased expression of HERV-K in melanoma cells correlates with malignant transformation, while a serological response to HERV-K in breast cancer or melanoma patients correlates with survival probability. However, the mechanism behind these observations remains obscure. Our laboratory reported that anti-HERV-K envelope (Env) protein antibodies show antitumor potential in targeting …

C-Jun N-Terminal Kinases Regulate Adenovirus-Mediated Autophagy And Antigen Presentation, Sarah R. Klein

Dissertations and Theses (Open Access)

Targeted immunotherapy with recombinant, oncolytic adenoviruses is under investigation for the treatment of cancer. Evidence indicates adenoviruses induce autophagy that is required for oncolysis, but the molecular regulation of autophagy in infected cells remains under investigation. Our data suggested the canonical pathway regulating starvation-induced autophagy was not implemented in adenovirus-induced autophagy; however, adenovirus infection triggered phosphorylation of c-Jun N-terminal kinases (JNK) that was essential for autophagy. Adenoviral replication within the host cell elicited JNK pathway activation leading to B cell lymphoma-2 (Bcl-2) phosphorylation. JNK-dependent Bcl-2 phosphorylation stimulated the dissociation of Bcl-2/beclin 1 heterodimers, enabling beclin 1 to initiate autophagy. Moreover, …

Studies Of Molecular Mechanisms Of Cranberry Mediated Healthspan Promotion In Caenorhabditis Elegans, Sujay Guha

All Dissertations

Extensive studies have demonstrated the potent ability of many nutraceuticals to alleviate the symptoms of aging and stress. We found that cranberry extract (CBE) supplementation at an optimum concentration could prolong Caenorhabditis elegans (C. elegans) lifespan in a manner of daf-16 and osr-1 dependence. Considering that aging is a progressive degeneration of physiological functions, it is intriguing to know whether CBE consumption may delay the age-related degenerative changes in animals. Thus, we examined the effect of CBE consumption on healthspan in C. elegans populations with different ages and age-related disorders. Our results suggest that long-term CBE supplementation leads to a …

Investigating Potential Bioactive Compounds From Rhodococcus And Their Effects On Mcf7 Breast Cancer Cells, Megan N. Crabtree

Electronic Theses and Dissertations

Many drugs used in the treatment of various cancers are derived from or influenced by compounds from nature. The soil bacterium Rhodococcus is of interest because of its identified secondary metabolic pathways and the production of novel natural antibiotics from several strains. In this study, a solid agar extraction method was used to collect compounds from strains of Rhodococcus. These bacterial compound extracts were then tested using a MTT assay in order to evaluate their effectiveness in augmenting MCF7 breast cancer cell death. The results of two way ANOVA analyses revealed 18 compound extracts from 15 strains of Rhodococcus that …

Validation Of Thermal Destruction Of Pathogenic Bacteria In Rendered Animal Products, Mary Hayes

All Dissertations

This study tested enumeration techniques for high fat food matrices and determined thermal death times in rendering animal products. Standard Class O phosphate/magnesium chloride dilution buffer series (Dilution Series A) and a modified (pre-warmed to 32oC) lecithin phosphate dilution buffer series (Dilution Series B) were used to enumerate a Salmonella cocktail from both poultry and beef rendering materials. Results of this study indicate use of a modified lecithin buffer did not improve Salmonella enumeration accuracy from rendering materials. Instead, the results suggested use of xylose lysine deoxycholate agar (XLD) with either buffer system accurately enumerated Salmonella from rendering materials. The …

Bacterially-Mediated Formation Of Rock Coatings In Kärkevagge, Swedish Lapland: A Mineralogical And Micro-Environmental Analog For Mars, Cassandra L. Marnocha

Graduate Theses and Dissertations

The search for past or present life on Mars is, for now, limited to surface environments. An often neglected surface environment that could have served as an abode for life and could presently preserve evidence of that life is that of rock coatings. Rock coatings are mineral accretions on rock surfaces. On Earth, they are widespread and occur with considerable chemical diversity. There is growing evidence for a biotic role in their formation on Earth, particularly with respect to rock varnish. As a result, rock varnish has become a target of astrobiological interest on Mars, where varnish-like coatings have been …

Role Of The Cipa Scaffoldin Protein In Cellulose Solubilization, As Determined By Targeted Gene Deletion And Complementation In Clostridium Thermocellum, Daniel G. Olson, Richard J. Giannone, Robert L. Hettich, Lee R. Lynd

Dartmouth Scholarship

The CipA scaffoldin protein plays a key role in the Clostridium thermocellum cellulosome. Previous studies have revealed that mutants deficient in binding or solubilizing cellulose also exhibit reduced expression of CipA. To confirm that CipA is, in fact, necessary for rapid solubilization of crystalline cellulose, the gene was deleted from the chromosome using targeted gene deletion technologies. The CipA deletion mutant exhibited a 100-fold reduction in cellulose solubilization rate, although it was eventually able to solubilize 80% of the 5 g/liter cellulose initially present. The deletion mutant was complemented by a copy of cipA expressed from a replicating plasmid. In …

Tracking The Cellulolytic Activity Of Clostridium Thermocellum Biofilms, Alexandru Dumitrache, Gideon M. Wolfaardt, David Allen, Steven N. Liss, Lee R. Lynd

Dartmouth Scholarship

Microbial cellulose conversion by Clostridium thermocellum 27405 occurs predominantly through the activity of substrate-adherent bacteria organized in thin, primarily single cell-layered biofilms. The importance of cellulosic surface exposure to microbial hydrolysis has received little attention despite its implied impact on conversion kinetics.

The Prince And The Pauper: Which One Is Real?: The Problem Of Secondary Mutation During Mutagenesis In Streptococcus Pyogenes, Kyu Hong Cho, Jordan O. Wright, Juan P. Svencionis, Jeong-Ho Kim

Biochemistry and Molecular Medicine Faculty Publications

No abstract provided.

Increased Cell Surface Free Thiols Identify Effector Cd8+ T Cells Undergoing T Cell Receptor Stimulation, Samuel Troy Pellom, Ryan D. Michalek, Katie E. Crump, P. Kent Langston, Daniel G. Juneau, Jason M. Grayson

Biology Faculty Articles

Recognition of peptide Major Histocompatibility Complexes (MHC) by the T cell receptor causes rapid production of reactive oxygen intermediates (ROI) in naïve CD8+ T cells. Because ROI such as H2O2 are membrane permeable, mechanisms must exist to prevent overoxidation of surface proteins. In this study we used fluorescently labeled conjugates of maleimide to measure the level of cell surface free thiols (CSFT) during the development, activation and differentiation of CD8+ T cells. We found that during development CSFT were higher on CD8 SP compared to CD4 SP or CD4CD8 DP T cells. After activation CSFT became elevated prior to division …

The Effect Of Media Selection On The Membrane Characteristics And Fatty Acid Composition Of Staphylococcus Aureus, Seth Russell Johnson

Theses and Dissertations

The cellular membrane is a vital structure to a microorganism and impacts important aspects of environmental regulation and growth. The physical structure of cellular membranes plays a key role in bacterial growth at low temperatures, membrane permeability and susceptibility to membrane active molecules as well as broader aspects of bacterial physiology and pathogenesis. Mueller Hinton medium is the required medium for antimicrobial susceptibility testing in the US, but there are many other types of media used in staphylococcal research. Different media vary in their nutrient compositions, and the effect of media composition on bacterial physiology is incompletely understood. The aim …

Taxis Toward Hydrogen Gas By Methanococcus Maripaludis, Kristen A. Brileya, James M. Connolly, Carey Downey, Robin Gerlach, Matthew W. Fields

Biology Faculty Publications and Presentations

Knowledge of taxis (directed swimming) in the Archaea is currently expanding through identification of novel receptors, effectors, and proteins involved in signal transduction to the flagellar motor. Although the ability for biological cells to sense and swim toward hydrogen gas has been hypothesized for many years, this capacity has yet to be observed and demonstrated. Here we show that the average swimming velocity increases in the direction of a source of hydrogen gas for the methanogen, Methanococcus maripaludis using a capillary assay with anoxic gas-phase control and time-lapse microscopy. The results indicate that a methanogen couples motility to hydrogen concentration …

National Park Service Cave Ecology Inventory And Monitoring Framework, Gretchen M. Baker, Steven J. Taylor, Shawn Thomas, Rick Olson, Kathy Lavoie, Marie Denn, Steven Thomas, Hazel Barton, Kurt Helf, Rene Ohms, Joel Despain, Jim Kennedy, David Larson

National Cave and Karst Management Symposium 2013

A team developed the Cave Ecology Inventory and Monitoring Framework for National Park Service (NPS) units. It contains information for NPS cave managers across the United States to determine how to inventory and monitor cave ecology. Due to the wide geographical scope of NPS caves and their many different types, the document does not prescribe exact protocols. Instead, it provides guidance for what types of inventory and monitoring are possible, a framework for deciding how to prioritize inventory and monitoring activities, and references to specific protocols that are already in place at NPS cave parks.

Keywords: cave ecology, cave microbiology, …

Novel Neuroprotective Function Of Apical-Basal Polarity Genecrumbs In Amyloid Beta 42 (Aβ42) Mediated Neurodegeneration, Andrew Steffensmeier, Meghana Tare, Oorvashi Roy Puli, Rohan Modi, Jaison Nainaparampil, Madhuri Kango-Singh, Amit Singh

Biology Faculty Publications

Alzheimer's disease (AD, OMIM: 104300), a progressive neurodegenerative disorder with no cure to date, is caused by the generation of amyloid-beta-42 (Aβ42) aggregates that trigger neuronal cell death by unknown mechanism(s). We have developed a transgenic Drosophilaeye model where misexpression of human Aβ42 results in AD-like neuropathology in the neural retina. We have identified an apical-basal polarity gene crumbs (crb) as a genetic modifier of Aβ42-mediated-neuropathology. Misexpression of Aβ42 caused upregulation of Crb expression, whereas downregulation of Crb either by RNAi or null allele approach rescued the Aβ42-mediated-neurodegeneration. Co-expression of full length Crb with Aβ42 increased severity of Aβ42-mediated-neurodegeneration, …

Study Of Coronavirus Protease Using Cfp-Yfp Fluorescent Assay, Caitlin E. Specht, Andrew Mesecar Ph.D., Katrina Molland Ph.D.

The Summer Undergraduate Research Fellowship (SURF) Symposium

Middle Eastern Respiratory Syndrome (MERS) is an emerging viral disease originating in the Arabian Peninsula with a current mortality rate of nearly fifty percent throughout Europe and Asia according to the World Health Organization. Characterization of this disease is being done to understand the basis of viral replication. One target for viral inhibition are replication proteases. Replication proteases are enzymes that cleave proteins specific to cell growth and reproduction that form the viral replicase complex making them an ideal target for viral replication inhibition. First, replication proteases were characterized using a fluorescence resonance energy transfer (FRET) construct by measuring the …

Wash Education: Need For More Than Water Treatment For Floating Villages In Cambodia, Kevin Curry

2013 New England Association for Asian Studies Conference

Point of use (POU) water treatment systems are widely used around the world to provide microbiologically safe drinking water in developing countries. Work done in Cambodia by Brown et al. (2007) and Liang et al. (2010) have documented ceramic and biosand filters as cost effective point of use treatment systems capable of removing over 95% E. coli bacteria when properly used and maintained. Bridgewater State University and Water for Cambodia (WfC) explored using BioSand filters (BSF) to provide microbiologically safe drinking water for people in the Moat Khla floating village on the Tonle Sap Lake in Siem Reap Province. All …