Microbiology Commons^™

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 …

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

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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 …

Short Communication: Antiretroviral Therapy Resistance Mutations Present In The Hiv Type 1 Subtype C Pol And Env Regions From Therapy-Naive Patients In Zambia, Sandra Gonzalez, Clement Gondwe, Damien C. Tully, Veenu Minhas, Danielle Shea, Chipepo Kankasa, Tendai M'Soka, Charles Wood

Nebraska Center for Virology: Faculty Publications

The prevalence of antiretroviral therapy (ART) resistance mutations present in HIV-1 subtype C pol and env regions of the proviral DNA was analyzed and compared from therapy-naive individuals before (Cohort A) and after (Cohort B) the availability of free ART in Zambia. Mutations present in sequences published in a previous study from Zambian ART-naive individuals infected with subtype C were analyzed using current parameters for the classification of ART drug resistance and compared with Cohorts A and B. No statistically significant differences were observed when comparing mutations present in the pol and env of these cohorts. However, an increase in …

Primary Gamma-Herpesviral Infection In Zambian Children, Veenu Minhas, Brad P. Brayfield, Kay L. Crabtree, Chipepo Kankasa, Charles D. Mitchell, Charles Wood

Nebraska Center for Virology: Faculty Publications

Background: HHV-8 is closely related to Epstein-Barr virus (EBV), but the clinical presentations of these two infections in early childhood are not well understood. Also, it is not known whether infection by one virus correlates with another. Here, we compare the natural history of infection by these two viruses along with the clinical manifestations and risk factors that are associated with early childhood infection in Zambia, which is an endemic area for HHV-8.

Methods: This study was conducted in a cohort of 12 month old Zambian children (N = 677). Data on socio-economic status and a wide range …

Restricted Genetic Diversity Of Hiv-1 Subtype C Envelope Glycoprotein From Perinatally Infected Zambian Infants, Hong Zhang, Damien C. Tully, Federico G. Hoffmann, Jun He, Chipepo Kankasa, Charles Wood

Nebraska Center for Virology: Faculty Publications

Background: Mother-to-child transmission of HIV-1 remains a significant problem in the resource-constrained settings where anti-retroviral therapy is still not widely available. Understanding the earliest events during HIV-1 transmission and characterizing the newly transmitted or founder virus is central to intervention efforts. In this study, we analyzed the viral env quasispecies of six mother-infant transmission pairs (MIPs) and characterized the genetic features of envelope glycoprotein that could influence HIV-1 subtype C perinatal transmission.

Methodology and Findings: The V1-V5 region of env was amplified from 6 MIPs baseline samples and 334 DNA sequences in total were analyzed. A comparison of …

Subtype-Associated Differences In Hiv-1 Reverse Transcription Affect The Viral Replication, Sergey Iordanskiy, Mackenzie Waltke, Yanjun Feng, Charles Wood

Nebraska Center for Virology: Faculty Publications

Background: The impact of the products of the pol gene, specifically, reverse transcriptase (RT) on HIV-1 replication, evolution, and acquisition of drug resistance has been thoroughly characterized for subtype B. For subtype C, which accounts of almost 60% of HIV cases worldwide, much less is known. It has been reported that subtype C HIV-1 isolates have a lower replication capacity than B; however, the basis of these differences remains unclear.

Results: We analyzed the impact of the pol gene products from HIV-1 B and C subtypes on the maturation of HIV virions, accumulation of reverse transcription products, integration …

Topological Layers In The Hiv-1 Gp120 Inner Domain Regulate Gp41 Interaction And Cd4-Triggered Conformational Transitions, Andrés Finzi, Shi-Hua Xiang, Beatriz Pacheco, Dana-Farber Cancer Institute Wang, Jessica Haight, Aemro Kassa, Brenda Danek, Marie Pancera, Peter D. Kwong, Joseph Sodroski

Nebraska Center for Virology: Faculty Publications

The entry of human immunodeficiency virus (HIV-1) into cells is initiated by binding of the gp120 exterior envelope glycoprotein to the receptor, CD4. How does CD4 binding trigger conformational changes in gp120 that allow the gp41 transmembrane envelope glycoprotein to mediate viral-cell membrane fusion? The transition from the unliganded to the CD4-bound state is regulated by two potentially flexible topological layers (layers 1 and 2) in the gp120 inner domain. Both layers apparently contribute to the noncovalent association of unliganded gp120 with gp41. After CD4 makes initial contact with the gp120 outer domain, layer 1-layer 2 interactions strengthen gp120-CD4 binding …

Neuroaids In Africa, Kevin Robertson, Jeff Liner, James Hakim, Jean-Louis Sankalé, Igor Grant, Scott Letendre, David Clifford, Amadou Gallo Diop, Assan Jaye, Georgette Kanmogne, Alfred Njamnshi, T. Dianne Langford, Tufa Gemechu Weyessa, Charles Wood, Mwanza Banda, Mina Hosseinipour, Ned Sacktor, Noeline Nakasuja, Paul Bangirana, Robert Paul, John Joska, Joseph Wong, Michael Boivin, Penny Holding, Betsy Kammerer, Annelies Van Rie, Prudence Ive, Avindra Nath, Kathy Lawler, Clement Adebamowo, Walter Royal Iii, Jeymohan Joseph

Nebraska Center for Virology: Faculty Publications

In July 2009, the Center for Mental Health Research on AIDS at the National Institute of Mental Health organized and supported the meeting “NeuroAIDS in Africa.” This meeting was held in Cape Town, South Africa, and was affiliated with the 5th IAS Conference on HIV Pathogenesis, Treatment and Prevention. Presentations began with an overview of the epidemiology of HIV in sub-Saharan Africa, the molecular epidemiology of HIV, HIV-associated neurocognitive disorders (HANDs), and HAND treatment. These introductory talks were followed by presentations on HAND research and clinical care in Botswana, Cameroon, Ethiopia, The Gambia, Kenya, Malawi, Nigeria, Senegal, South Africa, Uganda, …

Functional Properties Of The Hiv-1 Subtype C Envelope Glycoprotein Associated With Mother-To-Child Transmission, Hong Zhang, Marzena Rola, John T. West, Damien C. Tully, Piotr Kubis, Jun He, Chipepo Kankasa, Charles Wood

Nebraska Center for Virology: Faculty Publications

Understanding the properties of viruses capable of establishing infection during perinatal transmission of HIV-1 is critical for designing effective means of limiting transmission. We previously demonstrated that the newly transmitted viruses (in infant) were more fit in growth, as imparted by their envelope glycoproteins, than those in their corresponding mothers. Here, we further characterized the viral envelope glycoproteins from six mother-infant transmission pairs and determined whether any specific envelope functions correlate with HIV-1 subtype C perinatal transmission. We found that most newly transmitted viruses were less susceptible to neutralization by their maternal plasma compared to contemporaneous maternal viruses. However, the …

Chronology And Evolution Of The Hiv-1 Subtype C Epidemic In Ethiopia, Damien C. Tully, Charles Wood

Nebraska Center for Virology: Faculty Publications

Objective—To reconstruct the onset date and evolutionary history of the HIV-1 subtype C epidemic in Ethiopia - one of the earliest recorded subtype C epidemics in the world.

Design—HIV-1 C env sequences with a known sampling year isolated from HIV-1 positive patients from Ethiopia between 1984 and 2003.

Methods—Evolutionary parameters including origin and demographic growth patterns were estimated using a Bayesian coalescent-based approach under either strict or relaxed molecular clock models.

Results—Bayesian evolutionary analysis indicated a most recent common ancestor date of 1965 with three distinct epidemic growth phases. Regression analysis of root-to-tip distances revealed a highly similar estimate for …

Enhancement Of Autophagy During Lytic Replication By The Kaposi’S Sarcoma-Associated Herpesvirus Replication And Transcription Activator, Hui-Ju Wen, Zhilong Yang, You Zhou, Charles Wood

Nebraska Center for Virology: Faculty Publications

Autophagy is one of two major degradation systems in eukaryotic cells. The degradation mechanism of autophagy is required to maintain the balance between the biosynthetic and catabolic processes and also contributes to defense against invading pathogens. Recent studies suggest that a number of viruses can evade or subvert the host cell autophagic pathway to enhance their own replication. Here, we investigated the effect of autophagy on the KSHV (Kaposi’s sarcoma-associated herpesvirus) life cycle. We found that the inhibition of autophagy reduces KSHV lytic reactivation from latency, and an enhancement of autophagy can be detected during KSHV lytic replication. In addition, …

Evolutionary Aspects Of Urea Utilization By Fungi, Dhammika H. M. L. P Navarathna, Steven D. Harris, David D. Roberts, Kenneth W. Nickerson

Kenneth Nickerson Papers

The higher fungi exhibit a dichotomy with regard to urea utilization. The hemiascomycetes use urea amidolyase (DUR1,2), whereas all other higher fungi use the nickel-containing urease. Urea amidolyase is an energy-dependent biotincontaining enzyme. It likely arose before the Euascomycete/Hemiascomycete divergence c. 350 million years ago by insertion of an unknown gene into one copy of a duplicated methylcrotonyl CoA carboxylase (MccA). The dichotomy between urease and urea amidolyase coincides precisely with that for the Ni/Co transporter (Nic1p), which is present in the higher fungi that use urease and is absent in those that do not. We suggest that …

Candida Albicans Cellwall Components And Farnesol Stimulate The Expression Of Both Inflammatory And Regulatory Cytokines In The Murine Raw264.7 Macrophage Cell Line, Suman Ghosh, Nina Howe, Katie Volk, Swetha Tati, Kenneth W. Nickerson, Thomas M. Petro

Kenneth Nickerson Papers

Candida albicans causes candidiasis, secretes farnesol, and switches from yeast to hyphae to escape from macrophages after phagocytosis. However, before escape, macrophages may respond to C. albicans’ pathogen-associated molecular patterns (PAMPs) through toll-like receptor 2 (TLR2) and dectin-1 receptors by expressing cytokines involved in adaptive immunity, inflammation, and immune regulation. Therefore, macrophages and the RAW264.7 macrophage line were challenged with C. albicans preparations of live wild-type cells, heat-killed cells, a live mutant defective in hyphae formation, a live mutant producing less farnesol, or an isolate producing farnesoic acid instead of farnesol. Interleukin-6 (IL-6), and IL-1b, IL- 10, and tumor …

Bioinformatic And Sequence Analysis Of Four Resuscitation Promoting Factor (Rpf) Gene Homologues In Mycobacterium Avium Subsp. Paratuberculosis (Mpt), And Expression Of The Putative Mpt Rpfb In Escherichia Coli., David Dale Hedlund

All Graduate Theses, Dissertations, and Other Capstone Projects

Mycobacterium avium subsp. paratuberculosis (Mpt), the causative agent of Johne's disease (JD), is a global problem in the agricultural industry. It is estimated that 25% of all U.S. dairy herds are JD positive. One obstacle in the management of JD is the lack a sensitive diagnostic test for use during the early stages of infection. Resuscitation promoting factors (Rpf) are proteins that promote the growth of many species of Actinobacteria. If Rpf proteins could enhance the growth of Mpt, the sensitivity of diagnostic fecal culture could be improved, and the impact of JD on the dairy industry would be significantly …

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 …