Microbiology Commons^™

Construction And Characterization Of Non-Toxic Bacterial Enterotoxins As Vaccine Adjuvants, Lavanya Vempati

Boise State University Theses and Dissertations

The development of adjuvants that can promote the delivery of purified subunit vaccines by mucosal routes, such as the nose or the mouth, is recognized as a top priority for vaccine research. The bacterial enterotoxins; cholera toxin (CT) and E.coli heat-labile toxin (LTI), have long been recognized as powerful adjuvants with the ability to stimulate specific immune responses to co-administered antigens when delivered to mucosal surfaces. Shiga toxin 1 (ST1) and pertussis toxin (PT) are structurally homologous bacterial toxins secreted by Escherichia coli 0157:H7 and Bordetella pertussis respectively. ST1 and PT also have reported adjuvant activity but it is less …

Regulators Of Bacterial Cell Division: Investigations Of Min Oscillation And Ftsa Activity, Jennifer R. Herricks

Dissertations and Theses (Open Access)

Cytokinesis is a fundamental process that is essential for bacterial proliferation. The cytokinetic machinery in bacteria is termed the “divisome”. The divisome is a complex of proteins that forms a ring at midcell over dividing nucleoids. In order for daughter cells to form, the divisome must constrict. As constriction occurs, two new cell poles are formed, one for each daughter cell. The first step in divisome formation is the assembly of FtsZ into a Z ring. The work presented in this dissertation focuses on two proteins that regulate the Z ring: MinD, which is a part of the Min system …

Potential Roles Of Peroxidases In Caenorhabditis Elegans Innate Immunity, George R. Tiller, George R. Tiller

Dissertations and Theses (Open Access)

The production of ROS (reactive oxygen species) in response to pathogen detection is a rapid, nonspecific response that is evolutionarily conserved from nematodes to humans. ROS serve as direct and indirect effectors of innate and adaptive immunity. In Caenorhabditis elegans, a ROS burst is observed during infection and is mediated by the dual oxidase BLI-3, which produces H₂O₂. RNAi (RNA interference) to reduce the amount of BLI-3 results in a significant increase in susceptibility to pathogens, suggesting BLI-3 has a role in the immune response. However, H₂O₂ by itself is not a …

Development Of Chimeric Type Iv Secretion Systems For Transfer Of Heterologous Substrates Across The Gram-Negative Cell Envelope, Trista M. Berry

Dissertations and Theses (Open Access)

Many bacteria use Type IV Secretion Systems (T4SSs) to aid in pathogenesis by translocating virulence factors across the cell envelope and into eukaryotic cells. These systems are structurally and functionally diverse, but are often compared to the archetypal VirB/VirD4 T4SS of Agrobacterium tumefaciens. This system is composed of the VirD4 type IV coupling protein (T4CP) and 11 VirB subunits (VirB1-11) that assemble as the secretion channel and an extracellular pilus. The T4CP is an inner membrane ATPase that interacts with T4SS substrates and the secretion channel, and is thought to link substrates with the secretion channel and possibly energize …

Energy Stress Causes Chaperones To Assemble Into Cytoplasmic Complexes, Kimberly J. Cope

Dissertations and Theses (Open Access)

The majority of proteins require molecular chaperones to assist their folding into tertiary and quaternary structures. Certain stresses can compromise the weak hydrophobic forces responsible for these structures and lead to protein unfolding, misfolding, and aggregation. Aggregates of proteins are hallmarks of devastating diseases such as Alzheimer’s, Parkinson’s, and Huntington’s diseases. Fortunately, bacteria, plants, and fungi have a potent disaggregase, named Hsp104 in Saccharomyces cerevisiae. Recently, heat-induced aggregates, termed Q-bodies, were found to contain three molecular chaperones: Hsp70, Hsp104, and Hsp42. Their coalescence from small puncta into larger inclusions required Hsp104. During glucose deprivation, a stress that isn’t known to …

Development Of A Molecular Gram-Stain Assay For The Diagnosis Of Blood Stream Infections Associated With Sepsis, Douglas Bryan Litwin

Dissertations and Theses (Open Access)

Sepsis is a serious medical condition resulting from the severe dysregulation of the immune response that is generally triggered by infection. It affects more than 1.1 million Americans, has an average mortality rate of 30%, and is estimated to cost $24.3 billion annually. Currently, blood culture followed by Gram-stain analysis is the gold standard for diagnosing bacterial infections associated with sepsis. This method generates a high rate of false negative results and, in general, requires 20 to 48 hr to provide results. Both of these problems are related to the requirement that the bacterial pathogens grow under defined laboratory conditions. …

Probiotic Potential Of Bacterial Isolates From ‘Amabere Amaruranu’ Cultured Milk, Blaise B. Boyiri

Electronic Theses and Dissertations

Probiotics are viable nonpathogenic microbes that positively affect host health. Probiotics inhibit infection, activate immunity, and promote mucosal-barrier development. Many microbes have probiotic activity. Nonetheless, the selection of stable strains and their specific mechanism(s) of action are not fully elucidated. Bacteria from ‘Amabere amaruranu’ cultured milk from Kenya were isolated and identified by PCR sequence analysis of the 16S rRNA gene. Isolates were examined for stability to acid and bile, antimicrobial activity, mucin production, and degradation and sensitivity to antibiotics, hence their potential for probiotics. Lactobacillus isolates were acid unstable, bile-stable, nonmucinolytic, and presented antibacterial activity. L. rhamnosus cell fractions …

Il-12 Induced Modulation Of Tumor Derived Myeloid Cell Inflammatory Responsiveness., Courtney Jetun Mitchell

Electronic Theses and Dissertations

Tumor infiltrating and tumor associated myeloid cells (TIMs and TAMs) elaborate an array of factors that promote tumor growth and metastasis. IL-12, a potent inflammatory cytokine has been shown to induce regression of many cancers. We hypothesize that IL-12 augments the ability of TIMs and TAMs to respond to inflammatory stimuli providing a window in which these stimuli are more likely to promote tumor destruction. Related to this hypothesis, we asked two questions: (1) Does IL-12 directly change signaling events associated with inflammatory signal transduction? (2) Is IFN? required for the entirety of IL-12 induced enhancement of the response of …

The Show Cave Of Diros Vs. Wild Caves Of Peloponnese, Greece - Distribution Patterns Of Cyanobacteria, Vasiliki Lamprinou, Daniel B. Danielidis, Adriani Pantazidou, Alexandra Oikonomou, Athena Economou-Amilli

International Journal of Speleology

The karst cave ‘Vlychada’of Diros, one of the oldest show caves in Peloponnese, sustains extended phototrophic biofilms on various substrata – on rocks inside the cave including speleothems, and especially near the artificial lighting installation (‘Lampenflora’). After a survey of the main abiotic parameters (Photosynthetically Active Radiation -PAR, Temperature -T, Relative Humidity -RH, Carbon Dioxide -CO₂) three clusters of sampling sites were revealed according to Principal Component Analysis (PCA): i) the water gallery section predominately influenced by CO₂, ii) the dry passages influenced by RH and PAR, and iii) the area by the cave exit at …

Ammonia-Oxidizing Bacteria And Archaea Under Continuous Maize: The Influence Of Tillage, N Input And Aggregation On Abundance And Community Composition, Lauren Segal

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

Nitrification involves the oxidation of ammonium (NH₄⁺) and is an important component of the overall N cycle. Nitrification occurs in two steps; first by oxidizing ammonium to nitrite, and then to nitrate. The first step is often the rate limiting step. Until recently ammonia-oxidizing bacteria (AOB) were thought to be the sole contributors to this process; however, the discovery of crenarchaeota, ammonia-oxidizing archaea (AOA), in marine environments has led to further study of their role in nitrification. Current literature supports the dominance of AOA over AOB in terrestrial ecosystems; however, little is known about what drives their …

Metagenomic Identification Of A Novel Salt Tolerance Gene From The Human Gut Microbiome Which Encodes A Membrane Protein With Homology To A Brp/Blh-Family Beta-Carotene 15,15'-Monooxygenase, Eamonn P. Culligan, Roy D. Sleator, Julian R. Marchesi, Colin Hill

Department of Biological Sciences Publications

The human gut microbiome consists of at least 3 million non-redundant genes, 150 times that of the core human genome. Herein, we report the identification and characterisation of a novel stress tolerance gene from the human gut metagenome. The locus, assigned brpA, encodes a membrane protein with homology to a brp/blh-family β-carotene monooxygenase. Cloning and heterologous expression of brpA in Escherichia coli confers a significant salt tolerance phenotype. Furthermore, when cultured in the presence of exogenous β-carotene, cell pellets adopt a red/orange pigmentation indicating the incorporation of carotenoids in the cell membrane.

Microbial Diversity Of A Mediterranean Soil And Its Changes After Biotransformed Dry Olive Residue Amendment, José A. Siles, Caio T.C.C Rachid, Inmaculada Sampedro, Inmaculada García-Romera, James M. Tiedje

Dartmouth Scholarship

The Mediterranean basin has been identified as a biodiversity hotspot, about whose soil microbial diversity little is known. Intensive land use and aggressive management practices are degrading the soil, with a consequent loss of fertility. The use of organic amendments such as dry olive residue (DOR), a waste produced by a two-phase olive-oil extraction system, has been proposed as an effective way to improve soil properties. However, before its application to soil, DOR needs a pre-treatment, such as by a ligninolytic fungal transformation, e.g. Coriolopsis floccosa. The present study aimed to describe the bacterial and fungal diversity in a …

Oroya Fever And Verruga Peruana: Bartonelloses Unique To South America, Michael F. Minnick, Burt E. Anderson, Amorce Lima, James M. Battisti, Phillip G. Lawyer, Richard J. Birtles

Biological Sciences Faculty Publications

Bartonella bacilliformis is the bacterial agent of Carrión's disease and is presumed to be transmitted between humans by phlebotomine sand flies. Carrión's disease is endemic to high-altitude valleys of the South American Andes, and the first reported outbreak (1871) resulted in over 4,000 casualties. Since then, numerous outbreaks have been documented in endemic regions, and over the last two decades, outbreaks have occurred at atypical elevations, strongly suggesting that the area of endemicity is expanding. Approximately 1.7 million South Americans are estimated to be at risk in an area covering roughly 145,000 km2 of Ecuador, Colombia, and Peru. Although disease …

Cell Wall And Autolytic Properties Of A Cold-Sensitive Listeria Monocytogenes Mutant Deficient In Branched-Chain Fatty Acid Biosynthesis, Anthony M. Martini

Theses and Dissertations

Cellular membranes modulate several critical functions of bacterial physiology, including solute diffusion and nutrient transport. Biophysical properties of phospholipids, as well as environmental pressures such as temperature, can have a profound effect on these membrane functions and the kinetics of associated enzymes. Listeria monocytogenes is a facultative intracellular pathogen capable of robust low temperature growth, a characteristic thought to be facilitated by a membrane highly enriched in branched-chain fatty acids (BCFA). Mutants deficient in the biosynthesis of these fatty acids exhibit severe growth defects under low temperature and extreme pH conditions. Morphological investigations have also revealed these mutants to undergo …

Bartonella Henselae Infection And Host Response In The Zebrafish Embryo Model, Amorce Lima

USF Tampa Graduate Theses and Dissertations

The Gram-negative bacterium Bartonella henselae (Bh) is an emerging zoonotic pathogen that has been associated with a variety of human diseases including bacillary angiomatosis which is characterized by vasoproliferative tumor-like lesions on the skin and internal organs of some immunosuppressed individuals. Several virulence factors associated with Bartonella-induced pathogenesis have been characterized. However, the study of those virulence factors has been limited to in vitro cell culture systems due to the lack of a practical animal model. Therefore, we wanted to investigate whether the zebrafish embryo (Danio rerio) could be used to model human infection with Bh. We investigated …

In Silico Analysis Of Functional Single Nucleotide Polymorphisms In The Human Trim22 Gene, Jenna N Kelly, Stephen D Barr

Microbiology & Immunology Publications

Tripartite motif protein 22 (TRIM22) is an evolutionarily ancient protein that plays an integral role in the host innate immune response to viruses. The antiviral TRIM22 protein has been shown to inhibit the replication of a number of viruses, including HIV-1, hepatitis B, and influenza A. TRIM22 expression has also been associated with multiple sclerosis, cancer, and autoimmune disease. In this study, multiple in silico computational methods were used to identify non-synonymous or amino acid-changing SNPs (nsSNP) that are deleterious to TRIM22 structure and/or function. A sequence homology-based approach was adopted for screening nsSNPs in TRIM22, including six different in …

Effect Of Chemotherapy On The Microbiota And Metabolome Of Human Milk: A Case Report, Camilla Urbaniak, Amy Mcmillan, Michelle Angelini, Gregory B Gloor, Mark Sumarah, Jeremy P Burton, Gregor Reid

Microbiology & Immunology Publications

BACKGROUND: Human milk is an important source of bacteria for the developing infant and has been shown to influence the bacterial composition of the neonatal gut, which in turn can affect disease risk later in life. Human milk is also an important source of nutrients, influencing bacterial composition but also directly affecting the host. While recent studies have emphasized the adverse effects of antibiotic therapy on the infant microbiota, the effects of maternal chemotherapy have not been previously studied. Here we report the effects of drug administration on the microbiota and metabolome of human milk.

METHODS: Mature milk was collected …

Management Of Root Knot Nematode (Meloidogyne Incognita ) In Indiana Soybeans, David Edgardo Perla Martinez

Open Access Theses

The aim of this project was to evaluate different strategies for management of Root Knot Nematode (RKN) on soybean and tomato in Indiana. Seed treatments were evaluated under field and greenhouse conditions, but no effect on RKN populations was observed. Soybean lines evaluated for resistance to RKN under greenhouse conditions showed that six lines may be resistant to RKN. Four different commercial mustard cover crops were evaluated for their bio-fumigant impact on RKN populations in the production of tomato. Euruca sativa, Cv. Nemat was a poor host of RKN. A positive impact on the vigor of the tomato plants followed …

High Voltage Atmospheric Cold Plasma Treatment Of Refrigerated Chicken Eggs For Control Of Salmonella Enteritidis On External Surfaces, Yi Chen

Open Access Theses

The global market for eggs is projected to reach 1.154 trillion by the year 2015. The number one risk to consumers from chicken eggs is contamination with Salmonella Enteritidis (SE). FDA estimates each year 142,000 illnesses in the U.S. are caused by SE contamination in chicken eggs. The first objective of this research study was to evaluate a novel High Voltage Atmospheric Cold Plasma (HVACP) technology in reducing externally inoculated SE on refrigerated chicken eggs. Raw, chicken eggs attached with SE population (10 7 CFU/ml), were placed in plastic containers filled with either dry Air (22%O2 , 78%N2 ) or …

Shifting Of Vitamin D Deficiency To Hypervitaminosis And Toxicity, Aysha Habib, Hafsa Majid, Romaina Iqbal

Department of Pathology and Laboratory Medicine

No abstract provided.