Microbiology Commons^™

The Effects Of Uv Light On The Antimicrobial Activities Of Cave Actinomycetes, Devon Rule, Naowarat (Ann) Cheeptham Dr.

International Journal of Speleology

The goal of this study was to determine whether actinomycetes isolated from a volcanic cave in western Canada could produce novel antimicrobial compounds against six multidrugresistant pathogens when exposed to UV light. One hundred and seventy-six actinomycete strains isolated from Helmcken Falls Cave, Wells Gray Provincial Park, BC, were screened against six pathogens using the “plug assay” in UV light and no light conditions. Of the 176 strains tested, 100 or 57% of the cave actinomycete strains had antimicrobial activities against the pathogens in 124 different instances: 35 instances when exposed to UV and no light, 30 when exposed to ...

Evolutionary And Molecular Analysis Of Conserved Vertebrate Immunity To Fungi, Erin Carter

Honors College

The innate immune system is highly conserved amongst all multicellular organisms. Yet a constant battle exists between host cells and pathogens due to the rapid evolution of immune system components. Functional genomics and in silico methods can be employed to elucidate the evolutionary patterns of vertebrate immunity to pathogenic fungi such as Candida albicans, an opportunistic fungal pathogen that can cause lethal candidiasis in the immunocompromised. Mammals such as humans and mice possess conserved C-type lectin receptors that recognize the C. albicans cell wall. However, these receptors have not been identified in fish. Here I describe how we identified potential ...

Unmasking Candidiasis: A Mechanistic Model For Innate Immune-Fungal Cell Wall Dynamics, Erica Hidu

Honors College

Candida albicans is an opportunistic fungal pathogen that can cause a potentially lethal systemic infection in immunocompromised patients. Increasing drug resistance of Candida species to anti-fungal treatments makes the study of this pathogen ever more important. Study of the C. albicans cell wall provides insight into its importance in pathogenesis, immune recognition, and anti-fungal action. It has been shown that β- glucan, a masked component of the fungal cell wall and ligand for the immune receptor Dectin-1, becomes available for immune recognition in the mouse model of systemic candidiasis. To develop a mechanistic model to explain this unmasking, we investigated ...

Study Of Genes Relating To Degradation Of Aromatic Compounds And Carbon Metabolism In Mycobacterium Sp. Strain Kms, Chun Zhang

All Graduate Theses and Dissertations

Polycyclic aromatic hydrocarbons, produced by anthropological and natural activities, are hazardous through formation of oxidative radicals and DNA adducts. Growth of Mycobacterium sp. strain KMS, isolated from a contaminated soil, on the model hydrocarbon pyrene induced specific proteins. My work extends the study of isolate KMS to the gene level to understand the pathways and regulation of pyrene utilization. Genes encoding pyrene-induced proteins were clustered on a 72 kb section on the KMS chromosome but some also were duplicated on plasmids. Skewed GC content and presence of integrase and transposase genes suggested horizontal transfer of pyrene-degrading gene islands that also ...

Aerobic Degradation Of Α-, Β-, Γ-Hexachlorocyclohexane By Narragansett Bay Bacterioplankton, Ian M. Rambo

Senior Honors Projects

Hexachlorocyclohexanes (HCHs) are a family of chlorinated organic compounds that were previously used as agricultural insecticides. HCHs are recognized as persistent organic pollutants due to their toxicity, recalcitrant properties, and tendency to bioaccumulate in food webs. Although HCH was first synthesized in 1825, its use was not widespread until the discovery of the insecticidal activity of the γ-HCH isomer in 1942. γ-HCH and its toxic waste isomers α-HCH and β-HCH were banned from production and use by the United Nations in 2009, yet these chemicals still present environmental problems due to their persistence in soils and surface waters. HCHs continue ...

Analysis Of The Chondroitinase Operon Of Flavobacterium Columnare, Erin L. Sorlien

Senior Honors Projects

Analysis of the chondroitinase operon of Flavobacterium columnare

Erin Sorlien

Major

Cell and Molecular Biology, Chemistry

Advisor

Dr. David R. Nelson

Date

May 2, 2013

Keywords

Flavobacterium columnare, columnaris disease, chondroitin AC lyase, complementation, csl operon

Abstract
Flavobacterium columnare, an opportunistic bacterial pathogen of fish, is the causative agent of columnaris disease (CD). The bacterium is a Gram-negative rod that exhibits gliding motility and avidly forms biofilms. CD affects both wild and cultured freshwater fish, and continues to cause large economic losses to the fish farming industry. According to an investigation conducted by the National Animal Health Monitoring System, CD ...

Viral Infection: An Evolving Insight Into The Signal Transduction Pathways Responsible For The Innate Immune Response, Girish J. Kotwal, Steven Hatch, William L. Marshall

Open Access Articles

The innate immune response is initiated by the interaction of stereotypical pathogen components with genetically conserved receptors for extracytosolic pathogen-associated molecular patterns (PAMPs) or intracytosolic nucleic acids. In multicellular organisms, this interaction typically clusters signal transduction molecules and leads to their activations, thereby initiating signals that activate innate immune effector mechanisms to protect the host. In some cases programmed cell death-a fundamental form of innate immunity-is initiated in response to genotoxic or biochemical stress that is associated with viral infection. In this paper we will summarize innate immune mechanisms that are relevant to viral pathogenesis and outline the continuing evolution ...

Host-Pathogen Interactions Of Retroviruses, Abdul A. Waheed, Abraham L. Brass, Suryaram Gummuluru, Gilda Tachedjian

Open Access Articles

No abstract provided.

Herv-H Rna Is Abundant In Human Embryonic Stem Cells And A Precise Marker For Pluripotency, Federico A. Santoni, Jessica Guerra, Jeremy Luban

Open Access Articles

BACKGROUND: Certain post-translational modifications to histones, including H3K4me3, as well as binding sites for the transcription factor STAT1, predict the site of integration of exogenous gamma-retroviruses with great accuracy and cell-type specificity. Statistical methods that were used to identify chromatin features that predict exogenous gamma-retrovirus integration site selection were exploited here to determine whether cell type-specific chromatin markers are enriched in the vicinity of endogenous retroviruses (ERVs).

RESULTS: Among retro-elements in the human genome, the gamma-retrovirus HERV-H was highly associated with H3K4me3, though this association was only observed in embryonic stem (ES) cells (p < 10-300) and, to a lesser extent, in induced pluripotent stem (iPS) cells. No significant association was observed in nearly 40 differentiated cell types, nor was any association observed with other retro-elements. Similar strong association was observed between HERV-H and the binding sites within ES cells for the pluripotency transcription factors NANOG, OCT4, and SOX2. NANOG binding sites were located within the HERV-H 5'LTR itself. OCT4 and SOX2 binding sites were within 1 kB and 2 kB of the 5'LTR, respectively. In keeping with these observations, HERV-H RNA constituted 2% of all poly A RNA in ES cells. As ES cells progressed down a differentiation pathway, the levels of HERV-H RNA decreased progressively. RNA-Seq datasets showed HERV-H transcripts to be over 5 kB in length and to have the structure 5'LTR-gag-pro-3'LTR, with no evidence of splicing and no intact open reading frames.

CONCLUSION: The developmental regulation of HERV-H ...

Prevalence Of Avian-Pathogenic Escherichia Coli Strain O1 Genomic Islands Among Extraintestinal And Commensal E. Coli Isolates, Timothy J. Johnson, Yvonne Wannemuehler, Subhashinie Kariyawasam, James R. Johnson, Catherine M. Logue, Lisa K. Nolan

Veterinary Microbiology and Preventive Medicine Publications and Papers

Escherichia coli strains that cause disease outside the intestine are known as extraintestinal pathogenic E. coli (ExPEC) and include pathogens of humans and animals. Previously, the genome of avian-pathogenic E. coli (APEC) O1:K1:H7 strain O1, from ST95, was sequenced and compared to those of several other E. coli strains, identifying 43 genomic islands. Here, the genomic islands of APEC O1 were compared to those of other sequenced E. coli strains, and the distribution of 81 genes belonging to 12 APEC O1 genomic islands among 828 human and avian ExPEC and commensal E. coli isolates was determined. Multiple islands ...

Interaction Of Bacillus Anthracis Exosporium Protein Bcla With Complement Factor H And Spore Persistence In The Lung, Sarah A. Jenkins

UT GSBS Dissertations and Theses (Open Access)

Anthrax outbreaks in the United States and Europe and its potential use as a bioweapon have made Bacillus anthracis an interest of study. Anthrax infections are caused by the entry of B. anthracis spores into the host via the respiratory system, the gastrointestinal tract, cuts or wounds in the skin, and injection. Among these four forms, inhalational anthrax has the highest lethality rate and persistence of spores in the lungs of animals following pulmonary exposure has been noted for decades. However, details or mechanisms of spore persistence were not known. In this study, we investigated spore persistence in a mouse ...

Novel Neutralizing Antibody Assays For Recombinant Human Hookworm Na-Gst-1 Vaccine, Xi Chen, Brian Keegan, Peter J. Hotez, Jeffrey M. Bethony, Amar R. Jariwala

GW Research Days 2013

BACKGROUND

Necator Americanus, a human hookworm causes approximately 85% of the global hookworm infections. Hookworm ingest hemoglobin containing erythrocytes. Hemoglobin is further digested to Heme and Globin by hookworm's gut enzymes. Iron-containing Heme is a potent enzyme inhibitor and generates toxic reactive oxygen species which is toxic to hookworms. Hookworm's gut enzyme Na-GST-1 (Necator Americanus Glutathione S-Transferase-1) has been hypothesized to detoxify Heme. Na-GST-1 adjuvanted with Alhydrogel® is a new vaccine which is currently under clinical development. Na-GST-1 has two active sites, the ligand binding or Heme detoxification site (H-site) and the catalytic active glutathione ...

Antilisterial Characteristics Of Volatile Essential Oils, Leeann L. Slaughter

Theses and Dissertations--Animal and Food Sciences

This study explored the in vitro and in situ antilisterial inhibitory activity of 16 essential oils during indirect exposure: Spanish Basil oil (Ocimum basilicum), Bay oil (Pimenta racemosa), Italian Bergamot oil (Citrus bergamia), Roman Chamomile oil (Anthemis nobilis), Sir Lanka Cinnamon oil (Cinnamomum zeylanicum), Citral, Clove Bud oil (Syzygium aromaticum), Cumin Seed oil (cuminum cyminum), Eucalyptus oil (Eucalyptus globulus), Eugenol, Geranium extract (Pelargonium graveolens), Marjoram oil (Origanum majorana), Neroli extract (Citrus aurantium), Peppermint oil (Mentha piperita L.), Rosemary oil (Rosmarinus officinalis L.),and Spanish Sage oil (Salvia officinalis L.). All essential oils were tested against Listeria monocytogenes (ATCC 4644). In ...

The Genome Of Pelobacter Carbinolicus Reveals Surprising Metabolic Capabilities And Physiological Features, Muktak Aklujkar, Shelley A. Haveman, Raymond Didonato, Olga Chertkov, Cliff S. Han, Miriam L. Land, Peter Brown, Derek Lovley

Derek Lovley

Background

The bacterium Pelobacter carbinolicus is able to grow by fermentation, syntrophic hydrogen/formate transfer, or electron transfer to sulfur from short-chain alcohols, hydrogen or formate; it does not oxidize acetate and is not known to ferment any sugars or grow autotrophically. The genome of P. carbinolicus was sequenced in order to understand its metabolic capabilities and physiological features in comparison with its relatives, acetate-oxidizing Geobacter species.

Results

Pathways were predicted for catabolism of known substrates: 2,3-butanediol, acetoin, glycerol, 1,2-ethanediol, ethanolamine, choline and ethanol. Multiple isozymes of 2,3-butanediol dehydrogenase, ATP synthase and [FeFe]-hydrogenase were differentiated and ...

Validation Of Microwave Heating Instructions For The Destruction Of Salmonella Spp. In Microwaveable Foods, Carol J. Valenzuela

Dissertations & Theses in Food Science and Technology

Microwave heating instructions for three products (chicken nuggets, turkey pot-pies and mashed potato) were developed and validated based on end point temperatures using two microwave ovens (2,459 MHz; 700 W and 1,350 W). Heating instructions for chicken nuggets were validated using different configuration of product placement (edge or center of the carousel) and number of units (4, 6 and 8). Salmonella spp. reductions of 6.56 log CFU/g (700 W) were observed in chicken nuggets heated in groups of 4 and placed at the center of the carousel with 1 min 26 s of heating time with ...

An Investigation Of Plant-Microbe Interactions Under Cadmium Stress In Agar-Based Medium, Hydroponics, And Soil Studies, Melanie P. Columbus

University of Western Ontario - Electronic Thesis and Dissertation Repository

This thesis investigated plant-microbe-metal interactions at two scales: a single plant-microbe system and an agricultural rhizobacterial community. The first objective was to investigate the effectiveness of a plant growth-promoting rhizobacterium (PGPR) on mediating cadmium stress in a plant model system. Arabidopsis thaliana Col-0 was inoculated with Pseudomonas putida UW4, which in its wild type form has been reported to reduce plant stress by simultaneously metabolizing the ethylene precursor 1-aminocyclopropane-1-carboxylate (ACC) with the enzyme ACC deaminase and stimulating plant growth through the production of indole-3-acetic acid (IAA). A mutant strain that lacks ACC deaminase and a no bacteria treatment were used ...

Is Your Immunity Compromised By Being Nice To Your Bacteria? Insights From A Social Amoeba, William E. Callison

Undergraduate Research Symposium

Eukaryotes are dependent on beneficial microbes, but can be killed by harmful ones. How have they evolved responses that protect themselves from harmful bacteria while coddling the beneficial ones? An ideal system for investigating this relationship is the eukaryote social amoeba Dictyostelium discoideum because some clones carry commensal bacteria through the social state to use as future seed corn, while others do not. Most of its life, D. discoideum amoeba consume bacteria and divide by binary fission. Under starvation, amoebae aggregate into a multicellular body which crawls to light, then forms a fruiting body of 20% dead stalk cells and ...

Improving Oncolytic Vesicular Stomatitis Virus Through Modulation Of The Anti-Tumour Immune Response, Kyle B. Stephenson

Open Access Dissertations and Theses

Despite improvements in detection and treatment, cancer is the leading cause of death worldwide. Current treatment modalities have not been able to improve the mortality rates and significant toxicities limit efficacy. Therefore there is a need for development of novel therapeutics.

Oncolytic viruses have the ability to efficiently replicate in and destroy tumours while leaving normal tissues unharmed. These treatment platforms have been gaining momentum in recent years due to pre-clinical and clinical successes. Oncolytic viruses are extremely safe with limited toxicity observed in phase I/II clinical trials, and objective responses have been observed in some patients treated with ...

Exploring Anaerobic Reductive Dechlorination At Low Ph Environments, Yi Yang

Masters Theses

Chlorinated aliphatic hydrocarbons (CAHs), such as tetrachloroethene (PCE) and trichloroethene (TCE), are ubiquitously pollutants in aquifer sediments and groundwater due to their heavy usage in industry and inappropriate disposal in the last century. Among about 1300 NPL (National Priorities List) sites, PCE and TCE are the two most frequently detected hazardous contaminants.

Engineered bioremediation, including biostimulation and bioaugmentation, is a promising technology to clean those PCE and/or TCE contaminated sites. However, in many contaminated groundwater systems and hazardous waste sites, pH can be lower than 5 to 6. And release of HCl (strong acid) from anaerobic reductive dechlorination may ...

Fatty Acid Synthase 1 In Candida Albicans Virulence And The In Vitro Effects Of Fluconazole, Tetracycline In Combinatorial Therapy, Marissa Mandy Rodrigues

Masters Theses

Candida albicans, the causative agent of superficial and invasive mycoses, is a significant fungal pathogen associated with high mortality rates and considerable health-related costs. The most effective class of antifungals used for the treatment of candidiasis includes polyenes, echinocandins and azoles. However with the emergence of resistant strains, new antifungals are warranted for the effective treatment of candidiasis. Genes involved in biosynthetic enzymatic pathways that regulate metabolic processes are important for the survival of pathogenic fungi and can thus be exploited for the development of better antifungals. Fatty acid synthase 1, which is involved in the de novo biosynthesis of ...