Microbiology Commons^™

The Role Of Sumoylation Of Ledgf/P75 In Hiv-1 Infection, Murilo Tadeu Domingues Bueno

Open Access Theses & Dissertations

The lens epithelium-derived growth factor (LEDGF) proteins p75 and p52 are transcriptional co-activators that protect cells from stresses through modulation of stress and heat shock-related genes. Besides regulating such genes, LEDGF/p75 is also important in the process of HOX gene expression and leukemia transformation driven by the MLL histone methyl transferase complex. By exploiting a similar mechanism of interaction between LEDGF/p75 and MLL, the HIV-1 viral protein Integrase (IN) associates with LEDGF/p75 in order to execute efficient viral DNA integration. This present work has identified that LEDGF proteins are posttranslationally modified by SUMO-1 and -3. SUMOylation was found to target …

Hypervirulent Clostridium Difficile Strains: Adherence, Toxin Production And Sporulation, Michelle Marie Merrigan

Dissertations

Clostridium difficile is a leading cause of nosocomial infections, and recently emerged "hypervirulent" C. difficile strains have caused epidemics worldwide. We hypothesized that multiple factors were responsible for this phenotype, particularly the interaction of C. difficile with the epithelial cell, as well as toxin production and sporulation.

To test if host interaction varied in HV strains, we developed a quantitative host-cell adherence assay, and found that while C. difficile strains varied in adherence to human intestinal epithelial cells, hypervirulent strains were not significantly more adherent than other strains. The bacterial surface protein SlpA varied in both size and amount between …

Morphogenesis Of The Bacillus Anthracis Spore, Michael Mallozzi

Dissertations

With the ability to shut down metabolism, survive exposure to high degrees of heat, ultra-violet and ionizing radiation, digestive enzymes, and antimicrobials, the bacterial spore is one of the most-resistant forms of life on earth. Although most spores are harmless, several species' spores cause serious diseases such as tetanus, anthrax, gas gangrene, botulism, and diarrhea. Spore-forming bacteria differentiate into spores in response to stresses (especially starvation) in a multi-stage developmental pathway involving the coordinated expression of hundreds of genes and the formation of specialized protective organelles which surround and protect the spore during dormancy. The Bacillus anthracis spore (the causative …

An Evaluation Of Miru-Vntr Analysis And Spoligotyping For Genotyping Of Mycobacterium Bovis Isolates And A Comparison With Rflp Typing., Joanne Mclernon, Eamonn Costello, Orla Flynn, Gillian Madigan, Fergus Ryan

Articles

Strain typing of Mycobacterium bovis isolates based on the variable-number tandem repeats of mycobacterial interspersed repetitive units (MIRU-VNTR) and on spoligotyping was evaluated in this study and these typing methods were compared with restriction fragment length polymorphism (RFLP) typing. A total of 386 M. bovis isolates from cattle, badgers and deer in the Republic of Ireland that had previously been typed by IS6110, polymorphic GC-rich sequence (PGRS) and direct repeat (DR) RFLP were included in the study. Spoligotyping and analysis of six VNTR loci (2163a, 2163b, 2165, 4052, 2996 and 1895) was performed on the samples. RFLP was the method …

Pattern Recognition In Cytopathology For Papanicolaou Screening, Jonathan Blackledge, Dmitriy Dubovitskiy

Conference papers

A unique space oriented filer is presented in order to detect and isolate the cell of a nucleus for applications in cytopathology. A classification method for nuclei is then considered based on the application of a set of features which includes certain fractal parameters. Segmentation algorithms are considered in which a self-adjustable sharpening filter is designed to enhance object location. Although the methods discussed and the algorithms developed have a range of applications, in this work we focus the engineering of a system for automating a Papanicolaou screening test using standard optical images

Visible And Hyperspectral Imaging Systems For The Detection And Discrimination Of Mechanical And Microbiological Damage Of Mushrooms, Edurne Gaston

Doctoral

Horticultural products such as mushrooms are exposed to environmental conditions during their postharvest life, which may affect product quality. Loss of whiteness during storage is particularly important in the mushroom industry. Rough handling and distribution, fruiting body senescence and bacterial infections are among the main causes of mushroom discolouration. The aim of this work was to study the use of visible and hyperspectral imaging (HSI) systems for the detection and discrimination of mechanical and microbiological damage of mushrooms. This piece of research involved a) monitoring the browning of mushroom with visible computer imaging systems, b) investigating the effect of mechanical …

Analysing The Effects Of Loss Of Sin3 In Drosophila Melanogaster, Aishwarya Swaminathan

Wayne State University Dissertations

Sin3A has been previously shown to be an essential gene for Drosophila viability and is implicated in the regulation of cell cycle. In this study, we show that SIN3 is not only required for embryonic viability but also for post-embryonic development. Genetic analysis suggests that the different isoforms of SIN3 may regulate unique sets of genes during development. The developmental lethality occurring due to ubiquitous knock down of SIN3 is hypothesized to be to the result of defects in cell proliferation. Conditional knock down of SIN3 in the wing discs results in a curly wing phenotype in the adult fly. …

Immunomodulatory Effect Of Host And Fungal Eicosanoids During Host-Pathogen Interactions With Candida Albicans, Gitanjali Kundu

Wayne State University Dissertations

Candida albicans, an opportunistic fungal pathogen, poses a significant clinical threat to immunocompromised patients. Diseases associated with this fungus ranges from superficial mucosal infection to life-threatening systemic candidiasis. The mechanisms by which Candida persists at mucosal surfaces in the face of an adaptive response are unclear. Candida produces immunomodulatory oxylipins that cross-react functionally with host eicosanoids, which are considered to play important role in regulating innate and adaptive immune responses. Our objective was to characterize the role of prostaglandins produced by the host and this fungus during host pathogen interactions, both in vitro with dendritic cells (DCs) and macrophages, and …

Enterobacterial Repetitive Intergenic Consensus-Pcr (Eric-Pcr) Analysis Among Raw Vegetables Isolates Of Campylobacter Jejuni., Tuan Suraya Tuan Soh

Student Works (2010-2019)

A total of 20 (n=20) raw vegetable isolates of Campylobacter jejuni were examined for the presence of virulence genes and genetic diversity using enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) analysis. All C. jejuni isolates were obtained from the laboratory of Food Science and Biotechnology, University Putra Malaysia, Serdang, Selangor. When specific PCR amplification were determined, all raw vegetables isolates of Campylobacter jejuni contained cadF and ceuE genes. Whereas, 12 (12/20) isolates were positive cdtB and 6 (6/20) were positive cdtC. None of the C. jejuni isolates was cdtA positive. Using ERIC-PCR analysis, all 20 isolates of C. jejuni were …

Deconstructing Ihf-Mediated Inhibition Of The Complex Acs Promoter, David S. Thach

Dissertations

acs encodes a high affinity enzyme that permits survival during carbon starvation. As befits a survival gene, its transcription is subject to complex regulation. Previously, the Wolfe lab reported that CRP activates acs transcription by binding tandem DNA sites located upstream of the major acsP2 promoter and that the nucleoid protein IHF binds three specific sites located just upstream. The most proximal site (IHF III) exhibits reduced transcription compared to the full-length promoter or to a construct lacking all three IHF sites. The goal of my research was to understand how IHF III inhibits CRP-dependent acs transcription. First, I helped …

Antagonistic Activity Of Selected Marine-Derived Streptomyces Spp. Against Plesiomonas Shigelloides., Angelyn Melaya Kloni

Student Works (2010-2019)

In this study, primary and secondary screenings were conducted to evaluate the antibacterial and anti-yeast potential of the eleven selected marine-derived Streptomyces spp., particularly against P. shigelloides. The strains were categorized into three colour groups for morphological grouping according to the colour of aerial mycelium; namely grey, yellow green, and white colour groups. Diffusible pigments were produced by eight of the strains tested. Strain(s) from grey and white with red diffusible pigments colour groups displayed strong antibacterial activity. The yeasts tested were resistant to the bioactive metabolite(s) produced by some of the Streptomyces spp. which had shown high activity against …

Soil Organic Matter Fractions And Aggregate Distribution In Response To Tall Fescue Stands, I. P. Handayani, Mark S. Coyne, R. S. Tokosh

Plant and Soil Sciences Faculty Publications

The study was conducted to evaluate the influences of tall fescue management on soil organic matter fractions and macro- and microaggregate distribution. Soil samples were collected from four paired adjacent fields consisting of five years of tall fescue mono and poly stands in Western Kentucky. Soil samples from 0 to 15 cm and 15 to 30 cm soil depths were analyzed for soil organic C and N, particulate organic matter C (POM-C) and N (POM-N), macro- and micro aggregate distribution and C-associated with macro- and micro- aggregates. Significant effects were observed between stands for all the properties, except total C, …

Bryostatins: Biological Context And Biotechnological Prospects, Amaro E. Trindade-Silva, Grace E. Lim-Fong, Koty H. Sharp

Arts & Sciences Faculty Publications

Coral animals harbor diverse microorganisms in their tissues, including archaea, bacteria, viruses, and Bryostatins are a family of protein kinase C modulators that have potential applications in biomedicine. Found in miniscule quantities in a small marine invertebrate, lack of supply has hampered their development. In recent years, bryostatins have been shown to have potent bioactivity in the central nervous system, an uncultivated marine bacterial symbiont has been shown to be the likely natural source of the bryostatins, the bryostatin biosynthetic genes have been identified and characterized, and bryostatin analogues with promising biological activity have been developed and tested. Challenges in …

The Im-9 Cell Line: A Model For Evaluating Tcdd-Induced Modulation Of The Polymorphic Human Hs1,2 Enhancer Within The 3' Immunoglobulin Heavy Chain Regulatory Region, Ruth C. Chambers-Turner

Browse all Theses and Dissertations

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a disrupter, of B-cell differentiation, induces binding of the aryl hydrocarbon receptor (AhR) nuclear complex to dioxin responsive elements (DRE) within the mouse immunoglobulin heavy chain regulatory region (3'IgHRR), and produces a marked inhibition of 3'IgHRR activation, IgH expression, and antibody secretion in a well-characterized mouse B-cell line (CH12.LX). The mouse 3'IgHRR consists of at least four enhancers (hs3a; hs1,2; hs3b; hs4), and is highly homologous with the three enhancers (hs3; hs1,2; hs4) of the human 3'IgHRR. A polymorphism of the human hs1,2 enhancer (resulting in varying numbers of tandem repeats containing a DRE and κB site) has …

Rev Interacts With Tubulin Heterodimers To Cause Cell Cycle Defects, Poornima Kotha Lakshmi Narayan

Browse all Theses and Dissertations

Rev is a regulatory protein that plays an important role in the replication of HIV virus by post-transcriptionally promoting expression of viral proteins late in infection. Rev expression also slows cell growth, leads to an accumulation of cells in G2/M specifically before the spindle checkpoint, and can produce changes in ploidy. Because Rev is capable of depolymerizing microtubules (MTs) in vitro, possibly by a mechanism shared with Kinesin-13 proteins, themselves potent cellular MT depolymerases, I tested the hypothesis that these cellular defects were due to an interaction between Rev and tubulin.

To this end, Rev and select Rev mutants defective …

Study Of Bacterial Diversity In The Oral Cavity Of Malaysian Subjects., Teoh Wuen Yew

Student Works (2010-2019)

About 700 species of bacteria can inhabit the human oral cavity. This project initially investigated the bacterial diversity within the oral cavity of Malaysian subjects by using culture-dependent techniques and 16S rDNA sequence analysis. The second part of the research profiled the antibiotic resistance of the identified oral bacteria by the Etest method. Three sampling sites of the oral cavity from nine healthy subjects were analyzed: the tooth surface, gingival crevice, and dorsum of the tongue. The tooth surface was shown to harbor 41 species, gingival crevice harbored 51 species and tongue dorsum 41 species. On average, each subject carried …

Process Optimization For The Developmenht Of A Functional Beverage Based On Lactic Acid Fermentation Of Oats, Shilpi Gupta, Sabrina Cox, Nissreen Abu-Ghannam

Articles

Oats (Avena sativa) have received considerable interest for their high content of soluble and insoluble fibre and for their high fermentability upon applying probiotic lactic acid bacteria (LAB). In the present study, Box–Behnken optimization design was used to optimize three different levels of oat, sucrose and starter culture concentration on the final viable cell population of Lactobacillus plantarum for the development of a fermented drink. A second-order polynomial response surface equation was developed indicating the effect of the studied variables on L. plantarum growth. Contour maps generated using the response surface equation showed that the experimental variables significantly affected the …

Thermocrinis Minervae Sp. Nov., A Hydrogen And Sulfur-Oxidizing, Thermophilic Member Of The Aquificales From A Costa Rican Terrestrial Hot Spring, Sara L. Caldwell, Yitai Liu, Isabel Ferrera, Terry Beveridge, Anna-Louise Reysenbach

Biology Faculty Publications and Presentations

A thermophilic bacterium, designated strain CR11T , was isolated from a filamentous sample collected from a terrestrial hot spring on the south-western foothills of the Rincón volcano in Costa Rica. The Gram-negative cells are approximately 2.4–3.9 mm long and 0.5–0.6 mm wide and are motile rods with polar flagella. Strain CR11T grows between 65 and 85 6C (optimum 75 6C, doubling time 4.5 h) and between pH 4.8 and 7.8 (optimum pH 5.9–6.5). The isolate grows chemolithotrophically with S0 , S2O2{ 3 or H2 as the electron donor and with O2 (up to 16 %, v/v) as the sole electron …

Electric Pulses To Prepare Feeder Cells For Sustaining And Culturing Of Undifferentiated Embryonic Stem Cells, Lauren M. Browning, Tao Huang, Xiao-Hong Nancy Xu

Chemistry & Biochemistry Faculty Publications

Current challenges in embryonic-stem-cell (ESC) research include inability of sustaining and culturing of undifferentiated ESCs over time. Growth-arrested feeder cells are essential to the culture and sustaining of undifferentiated ESCs, and they are currently prepared using gammaradiation and chemical inactivation. Both techniques have severe limitations. In this study, we developed a new, simple and effective technique (pulsed-electric-fields, PEFs) to produce viable growth-arrested cells (RTS34st) and used them as high-quality feeder cells to culture and sustain undifferentiated zebrafish ESCs over time. The cells were exposed to 25 sequential 10- nanosecond-electric-pulses (10nsEPs) of 25, 40 and 150 kV/cm with 1s pulse interval, …

Chloroquine Susceptibility And Reversibility In A Plasmodium Falciparum Genetic Cross, Jigar J. Patel, Drew Thacker, John C. Tan, Perri Pleeter, Lisa Checkley, Joseph M. Gonzales, Bingbing Deng, Paul D. Roepe, Roland A. Cooper, Michael T. Ferdig

Biological Sciences Faculty Publications

Mutations in the Plasmodium falciparum chloroquine (CQ) resistance transporter (PfCRT) are major determinants of verapamil (VP)-reversible CQ resistance (CQR). In the presence of mutant PfCRT, additional genes contribute to the wide range of CQ susceptibilities observed. It is not known if these genes influence mechanisms of chemosensitization by CQR reversal agents. Using quantitative trait locus (QTL) mapping of progeny clones from the HB3 x Dd2 cross, we show that the P. falciparum multidrug resistance gene 1 (pfmdr1) interacts with the South-East Asia-derived mutant pfcrt haplotype to modulate CQR levels. A novel chromosome 7 locus is predicted to contribute …