Microbiology Commons^™

Development Of A Predictive Modeling System For Validation Of The Cumulative Mirobial Inactivation Of The Salmonellae In Pepperoni Utilizing A Non-Pathogenic Surrogate Microorganism (Enterococcus Faecalis), Scott Donald Stillwell

Graduate Theses and Dissertations

Salmonellosis is the most frequently occurring bacterial foodborne illness in the United States and the human case rate has not improved for the past two decades. The federal agency responsible for oversight of meat and poultry processors has announced the intent to extend existing pathogen reduction performance standards for Salmonella spp. to cover all classes of products including fermented sausages that are currently produced under HACCP plans that are validated for control of Escherichia coli O157:H7. The proposed regulatory modifications will require processors to revalidate HACCP plan controls to achieve either a 6.5 or a 7.0 log10 inactivation of the …

Proteomic Studies Of The Influenza Virus-Human Cell Interactions: The Responses Of Host Cell Protein Expression To Viral Infection And The Novel Host Proteins That Interact With Virus Protein Ns1, Yimeng Wang

Graduate Theses and Dissertations

Influenza A viruses (IAVs) continue to be a threat to human health. Despite extensive studies, the mechanisms underlying the IAVs-host interactions during IAV infection remain elusive. We employed quantitative proteomic methods to systematically explore the host cell protein expression responses to IAV infection and examine the function of a critical IAV protein called NS1 by identifying its host binding partners. Specifically, we used a 2-dimentional gel electrophoresis (2-DE) based proteomic method to screen host proteins whose expression was substantially altered by IAV. One critical protein named IκB kinase-gamma (IKKγ) was found to be significantly down-regulated during IAV infection. Functional studies …

Litter Conditioning Is Differentially Affected By Leaf Species, Phosphorus Enrichment, And Light Availability, Erin E. Scott

Graduate Theses and Dissertations

Anthropogenic enrichment of nitrogen and phosphorus is one of the most pervasive and detrimental threats to aquatic ecosystems worldwide. In streams that rely on allochthonous basal food resources, such as leaves, nutrient pollution can result in altered food quality and decreased carbon (C) standing stocks. However, the magnitude and mechanisms of this change in quality are poorly understood. Laboratory microcosm studies were conducted to 1) quantify the response of litter C:P to a gradient of phosphorus (P) enrichment (0, 0.05, and 0.5 mg SRP/L) across leaf species with variable levels of degradability (sugar maple and oak), and 2) quantify the …

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

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Polycyclic aromatic hydrocarbons are produced from incomplete combustion of organic materials by human or natural activities. These polycyclic aromatic hydrocarbons are classified as pollutants because of their toxic, mutagenic, and carcinogenic characteristics. Mycobacterium sp. strain KMS, isolated from a contaminated soil, grows on the model polycyclic aromatic hydrocarbon, pyrene, with its degradation to water and carbon dioxide. This study locates genes on the chromosome and plasmids of isolate KMS relating to pyrene degradation, elucidates the influence of other carbon sources available in the habitats of isolate KMS on degradation of pyrene, and deduces possible metabolic pathways used by isolate …

Characterization Of Human Gut Microbiota Dynamics Using Model Communities In Gnotobiotic Mice, Nathaniel Patrick Mcnulty

All Theses and Dissertations (ETDs)

The human gut is colonized by a diverse array of microbes, collectively referred to as the microbiota. The microbiota's complexity poses significant challenges in characterizing the rules dictating its assembly, inferring the functional roles of its component species, and understanding how communities sense and respond to changes in their habitat. We developed defined, representative model communities comprised of sequenced human gut bacteria that could be characterized in a highly controlled manner in gnotobiotic mice, plus a suite of scalable molecular tools for assaying community properties. These tools were first used to evaluate how the microbiota is impacted by probiotic bacterial …

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

Department of Food Science and Technology: Dissertations, Theses, and Student Research

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 a target end point …

The Influence Of Diet On The Mammalian Gut Microbiome, Brian David Muegge

All Theses and Dissertations (ETDs)

The mammalian gut is residence to a large microbial community whose collective set of millions of genes: microbiome) encodes a vast array of functions, including many that process dietary components. Few tools are available to change the microbiome's properties to promote host health because the factors governing community assembly and operation are poorly understood. My thesis focused on the impact of one factor, host diet.

I used a variety of experimental and computational methods to perform a comparative metagenomic study of the fecal communities of 39 diverse mammals to assess microbiome variation. These animals included herbivores, omnivores and carnivores representing …

Enrollment In Yfv Vaccine Trial: An Evaluation Of Recruitment Outcomes Associated With A Randomized Controlled Double-Blind Trial Of A Live Attenuated Yellow Fever Vaccine, Paula M. Frew, Eve T. Shapiro, Lu Lu, Srilatha Edupuganti, Harry L. Keyserling, Mark J. Mulligan

Environmental & Global Health Faculty Research

This investigation evaluated several factors associated with diverse participant enrollment of a clinical trial assessing safety, immunogenicity, and comparative viremia associated with administration of 17-D live, attenuated yellow fever vaccine given alone or in combination with human immune globulin. We obtained baseline participant information (e.g., sociodemographic, medical) and followed recruitment outcomes from 2005 to 2007. Of 355 potential Yellow Fever vaccine study participants, 231 cases were analyzed. Strong interest in study participation was observed among racial and ethnically diverse persons with 36.34% eligible following initial study screening, resulting in 18.75% enrollment. The percentage of white participants increased from 63.66% (prescreened …

Molecular Mechanisms Of Lupus Risk Conferred By Allele In The Gene For Interferon Response Factor 5, Dr. Brian Poole

Journal of Undergraduate Research

The academic objectives of this proposal were met. Using the funding provided by the MEG, we generated data that was used to publish four peer-reviewed journal articles and one peer-reviewed book chapter. These are:

Transcriptional Activity Of The Novel Nuclear Protein Nbmp-2, Dr. Laura Bridgewater

Journal of Undergraduate Research

The goal of this project was to follow up on preliminary data suggesting that nBmp2 directly activated transcription. A few months of follow-up experiments, however, showed that the original transcription data was not reproducible. At that point we turned our attention to two different questions about nBmp2 function: 1) Does nBMP-2 affect the cell cycle? 2) Is nBMP-2 involved in the immune response? These questions have each yielded interesting and important results that are leading toward publications and grant proposals.

Development Of Real-Time Polymerase Chain Reaction (Q-Pcr) Assays For The Specific Detection And Characterization Of Select Bacterial Pathogens, Dr. Richard Robison

Journal of Undergraduate Research

Primer generation software will be used to design primer and probe sequences that will theoretically perform optimally in PCR reactions. All sequences will be subjected to BLAST searches to confirm their specificity for a particular organism. Once primer sequences have been obtained, they will be synthesized by Integrated DNA Technologies, Inc. (IDT). These primers will be evaluated in q-PCR reactions using target DNA from multiple isolates and SyberGreen to detect nucleic acid amplification. Parameters for each reaction will be optimized using these same tools. Once a reaction has been optimized, a specific labeled probe will be synthesized which contains both …

Cytokine Signaling In The Microenvironment May Aid In Tumor Development And Progression, Dr. Kim O'Neill

Journal of Undergraduate Research

Studies have indicated that in breast tumors a high number of tumor associated macrophages (TAM’s) is indicative of a poor prognosis. TAM’s in the breast tumor microenvironment generally have a compromised immune response and focus their energy toward tissue repair which leads to angiogenesis, tumor growth, and metastasis. These macrophages have been termed M2 macrophages. Conversely, studies also indicate that in the microenvironment of some colon cancers, M1 phenotypic macrophages are present and that a high number of TAM’s is associated with a good prognosis.

A Novel Nuclear Variant Of Nbmp-2: Role In Ca2+ Transport, Dr. Laura Bridgewater

Journal of Undergraduate Research

The goal of this project was to elucidate the role that nBMP-2 plays in Ca2+ transport. In the previous year, we demonstrated that mice that have no nBMP-2 in the nuclei of their cells exhibit delays in the transport of Ca2+ back into the sarcoplasmic reticulum after each muscle contraction. During the period of this award we have extended our focus on nBMP-2 and Ca2+ transport to its effects on neurological function, since learning and memory are also dependent on intracellular Ca2+ transport. To do so, we collaborated with Dr. Jeff Edwards, a neuroscientist in the Department of Physiology and …

Interferon Alpha In Systemic Lupus Erythematosus, Dr. Brian Poole

Journal of Undergraduate Research

We presented data from this project at two meetings, 2 presentations at the American society for Microbiology Branch Meeting, Provo UT 2010 and one at the Intermountain Research Symposium, Logan Utah 2010. At the ASM meeting one of my undergraduates was selected to give an oral presentation, and all presentations were done by students. We also published a paper with student authorship that was supported by the MEG. The paper is “Neiwold, Timothy; Clark, Daniel; Salloum, Rafeh; Poole Brian D. Interferon alpha in systemic lupus erythematosus. J Biomed Biotechnol. 2010;2010:948364” We also have three manuscripts in preparation that include data …

Secretion Of Tcpf By The Vibrio Cholerae Toxin-Coregulated Pilus Biogenesis Apparatus Requires An N-Terminal Determinant, Christina J. Megli, Ronald K. Taylor

Dartmouth Scholarship

Type IV pili are important for microcolony formation, biofilm formation, twitching motility, and attachment. We and others have shown that type IV pili are important for protein secretion across the outer membrane, similar to type II secretion systems. This study explored the relationship between protein secretion and pilus formation in Vibrio cholerae. The toxin-coregulated pilus (TCP), a type IV pilus required for V. cholerae pathogenesis, is necessary for the secretion of the colonization factor TcpF (T. J. Kirn, N. Bose, and R. K. Taylor, Mol. Microbiol. 49:81–92, 2003). This phenomenon is not unique to V. cholerae; secreted …

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 binding …

Activities Of Methionine-Γ-Lyase In The Acidophilic Archaeon “Ferroplasma Acidarmanus” Strain Fer1, M. A. Khan, Madeline M. Lopez-Munoz, Charles W. Kaspar, Kai F. Hung

Faculty Research & Creative Activity

Biogeochemical processes on exposed pyrite ores result in extremely high levels of sulfuric acid at these locations. Acidophiles that thrive in these conditions must overcome significant challenges, including an environment with proton concentrations at pH 3 or below. The role of sulfur metabolism in the archaeon “Ferroplasma acidarmanus” strain fer1’s ability to thrive in this environment was investigated due to its growth-dependent production of methanethiol, a volatile organic sulfur compound. Two putative sequences for methionine- γ-lyase (EC 4.4.1.11), an enzyme known to carry out α,γ-elimination on L-methionine to produce methanethiol, were identified in fer1. Bioinformatic analyses identified a conserved pyridoxal-5′-phosphate …

Activities Of Methionine-Γ-Lyase In The Acidophilic Archaeon “Ferroplasma Acidarmanus” Strain Fer1, M. Khan, Madeline Lopez-Munoz, Charles Kaspar, Kai Hung

Faculty Research & Creative Activity

Biogeochemical processes on exposed pyrite ores result in extremely high levels of sulfuric acid at these locations. Acidophiles that thrive in these conditions must overcome significant challenges, including an environment with proton concentrations at pH 3 or below. The role of sulfur metabolism in the archaeon “Ferroplasma acidarmanus” strain fer1’s ability to thrive in this environment was investigated due to its growth-dependent production of methanethiol, a volatile organic sulfur compound. Two putative sequences for methionine- γ-lyase (EC 4.4.1.11), an enzyme known to carry out α,γ-elimination on L-methionine to produce methanethiol, were identified in fer1. Bioinformatic analyses identified a conserved pyridoxal-5′-phosphate …

A Review Of G6pd Deficiency In Pakistani Perspective, Bushra Moiz

Department of Pathology and Laboratory Medicine

No abstract provided.

Frequency Of Precancerous Lesions In Endoscopic Gastric Biopsies In Chronic Gastritis, Saroona Haroon, Naveen Faridi, Faisal Rashid Lodhi, Shafaq Mujtaba

Department of Pathology and Laboratory Medicine

Objective:
To determine the frequency of precancerous lesions in endoscopic gastric biopsies of patients with chronic gastritis.STUDY Design: A case series.
Place and duration of study:
Department of Histopathology, Liaquat National Hospital, Karachi, from July 2008 to January 2009.METHODOLOGY: Over 6 months, 375 endoscopic gastric biopsies of patients with age group of 15-65 years having endoscopic chronic gastritis were included. From final biopsy report, basic information like patient demographics and presence of precancerous lesions i.e. activity (chronic active gastritis), atrophy (atrophic gastritis), intestinal metaplasia and dysplasia were recorded on proforma. Results were described as proportions and frequency.
Results:
The frequency …