Microbiology Commons^™

Listeria Monocytogenes Can Utilize Both M Cell Transcytosis And Inla-Mediated Uptake To Cross The Epithelial Barrier Of The Intestine During An Oral Infection Model Of Listeriosis, Hilary Denney

Theses and Dissertations--Medical Sciences

The invasive pathways, InlA- and InB-mediated uptake and M cell transcytosis, that Listeria monocytogenes uses to invade the intestine have mainly been studied using infection models that do not truly replicate what occurs during a natural infection. Recently, our lab has developed an oral infection model that is more physiolocally relevant to what occurs during food borne listeriosis. We have sought to evaluate the relative roles of the previously defined invasive pathways, in our oral model of infection. We have done this by utilizing an InlAmCG Lm strain that is able to bind murine E-cadherin, knockout Lm strains, ΔinlA Lm …

Role Of Viral And Host Factors In Influenza Virus Mediated Inhibition Of Interleukin-23, Ashish Tiwari

Theses and Dissertations--Veterinary Science

Influenza virus is one of the major respiratory pathogens of humans as well as animals, including equines. There is an increasing evidence that bacterial infections are the most common cause of the death during influenza. In horses also, secondary bacterial pneumonia can lead to death, and surviving horses may take up to six months for the complete recovery resulting in heavy economic loss to the equine industry. Interleukin (IL)-23 mediated innate immune response has been shown to protect the host from various respiratory bacterial infections. However, studies to investigate the role of host and viral factors in the regulation of …

Relationships Between Equine Management Practices And Intestinal Parasite Infection, Abigail Pagel

Honors Projects

Parasitology is an important area of veterinary medicine, but the risk factors for high parasite loads are not well-understood. Equine intestinal parasites can cause extensive disease and death. In the current study, the relationship between equine intestinal parasite loads and adherence to veterinary guidelines for equine management practices was studied. Satisfactory adherence to guidelines regarding food, pasture, and flooding management was related to lower parasite loads. Adherence to guidelines regarding deworming, quarantine, bedding, and water did not appear to lower parasite loads. Still, adhering to these guidelines has been shown to improve equine welfare, even if they are not related …

The Effects Of Sugar Substitutes On The Gut Microbiota Of Mice, Katie A. Lantau

All Master's Theses

Obesity has become an ever increasing global problem. This has caused people to turn to sugar substitutes, no calorie sweeteners, to reduce their caloric intake. However, recent studies have shown that it is not just caloric intake that can affect weight, but also the diversity of the bacteria in the gut (Turnbaugh et al., 2009). It has been shown that an increased Firmicutes:Bacteroidetes ratio and an overall decrease in microbial diversity leads to an obesity associated gut microbiome (Turnbaugh et al., 2009; Ley et al., 2005). The purpose of this study was to determine if two of the most popular …

Virus Purification, Detection And Removal, Khrupa Saagar Vijayaragavan

Dissertations, Master's Theses and Master's Reports - Open

The biopharmaceutical industry has a growing demand and an increasing need to improve the current virus purification technologies, especially as more and more vaccines are produced from cell-culture derived virus particles. Downstream purification strategies can be expensive and account for 70% of the overall manufacturing costs. The economic pressure and purification processes can be particularly challenging when the virus to be purified is small, as in our model virus, porcine parvovirus (PPV). Our efforts are focused on designing an easy, economical, scalable and efficient system for virus purification, and we focused on aqueous two-phase systems. Industry acceptable standards for virus …

Novel Cul3 Binding Proteins Function To Remodel E3 Ligase Complexes, Wananit Wimuttisuk, Mark West, Brittney Davidge, Kebing Yu, Arthur Salomon, Jeffrey D. Singer

Biology Faculty Publications and Presentations

Background: Cullins belong to a family of scaffold proteins that assemble multi-subunit ubiquitin ligase complexes to recruit protein substrates for ubiquitination via unique sets of substrate adaptor, such as Skp1 or Elongin B, and a substrate-binding protein with a conserved protein-protein interacting domain, such as leucine-rich repeats (LRR), a WD40 domain, or a zinc-finger domain. In the case of the Cullin3 (Cul3), it forms a BTB-Cul3-Rbx1 (BCR) ubiquitin ligase complex where it is believed that a BTB domain-containing protein performs dual functions where it serves as both the substrate adaptor and …

The Distribution Of Fitness Effects Of Spontaneous Mutations In Vibrio Fischeri, Chelsea K. Jones

Honors Theses and Capstones

Mutations are the ultimate source of the biological diversity on which natural selection acts, but the vast majority of these mutations are harmful. As such, mutations lead to disease states like cancer, extinction of small populations, and can drive pathogen evolution. Unfortunately, because mutations are rare and past studies have been subject to detection biases, very little is known about the distribution of fitness effects from naturally occurring mutations. In this study, we used mutation accumulation and full genome sequencing to capture naturally occurring mutations before they were exposed to the sieve of natural selection in Vibrio fischeri. We …

Differentiation Of U-937 Monocytes To Macrophage-Like Cells Polarized Into M1 Or M2 Phenotypes According To Their Specific Environment: A Study Of Morphology, Cell Viability, And Cd Markers Of An In Vitro Model Of Human Macrophages, Fatma Husien S. Abdulhadi

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In this study, the human leukemic monocyte lymphoma cell line U-937 was used as an in vitro model for monitoring monocyte/macrophage differentiation. Phorbol 12- myristate (13) (PMA) was used to activate U-937 cells into macrophage-like cells (M0). After 24 hours of PMA treatment, non- adherent U-937 cells became tightly adherent to the culture plates forming M0 cells. M0 cells were then polarized into the M1 macrophage phenotype by treatment with LPS and IFN-γ for another 24 hours. Each of the cytokines IL-4, IL-13, or IL-10 was applied separately to three M0 cultures for 24 hours to induce the M2 macrophage …

Sumoylation Affects Ns1'S Ability To Neutralize The Interferon Response, Jeanette Cecilia Gonzalez

Open Access Theses & Dissertations

It is of huge concern the possibility that at some point in the future we may face a new pandemic involving a highly pathogenic virus due to our current preventive and treatment options to fight this viral disease. The main reason for such limitations is the ability of the virus to go over constant antigenic shifts and drifts on its viral surface proteins HA and NA. The constant mutations that affect this virus cause the need of developing new vaccines for each influenza season. Periodically, the World Health Organization (WHO) reports that around 10% of the world population gets infected …

The Role Of Surface Chemistry In The Toxicity Of Manufactured Cerium Dioxide Nanomaterials To Caenorhabditis Elegans, Emily Kay Oostveen

Theses and Dissertations--Plant and Soil Sciences

Manufactured CeO₂ nanomaterials (CeO₂-MNMs) are used for a wide variety of applications including diesel fuel additives and chemical/mechanical planarization media. To test the effects of CeO₂-MNM surface coating charge on to model organism Caenorhabditis elegans, we synthesized 4 nm CeO₂ with cationic (DEAE-), anionic (CM-), and neutral (DEX) coatings. In L3 nematodes exposed for 24 hours, DEAE-CeO₂ induced lethality at lower concentrations than CM- or DEX-CeO₂. Feeding slightly decreased CeO₂ toxicity, regardless of coating. In L2 nematodes exposed for 48 hours with feeding, DEAE-CeO₂ caused lethality at the …

Coronavirus Proteases As Therapeutic Targets: Development Of Biosensors To Detect Inhibition Of Protease Activity And Separation Of The Multiple Functions Of Coronavirus Papain-Like Proteases, Andrew Kilianski

Dissertations

Coronaviruses are important human pathogens and have the potential to severely impact public health on an international scale. The emergence of SARS-CoV and MERS-CoV highlight the need for research to identify antivirals and vaccines against coronaviruses. To develop therapeutics against current and potentially emergent coronaviruses, I utilized two approaches targeting the proteases encoded within all coronaviruses. The papain-like protease and 3C-like protease of coronaviruses are responsible for cleaving viral polyproteins early during infection, and this step is required for viral replication. To quantitatively assess the inhibition by small-molecule compounds on MERS-CoV protease activity, I developed a luciferase-based biosensor to monitor …

Role Of The Pkna And Pknb Kinases In Mycobacterium Tuberculosis, Tripti Anandan

Wayne State University Dissertations

To respond to environmental changes, M. tuberculosis possesses eleven "eukaryotic-type" Ser/Thr protein kinases. The aim of the study described in this dissertation was to identify role of two of these kinases; PknA and PknB that are essential in M. tuberculosis. Two approaches are described to screen for potential in vivo substrates of PknA/PknB. First approach is based on proteomic search by over-expressing PknA/PknB in M. tuberculosis. Proteomic search led to identification of proteasome to be a substrate of PknA and PknB in M. tuberculosis. Furthermore, I demonstrate that the phosphorylation of PrcA and PrcB by PknA regulates processing of Pre-PrcB. …

The Mechanism For Inhibition Of Vibrio Cholerae Virulence Gene Expression By Bile And Its Fatty Acid Components, Sarah Plecha

Wayne State University Dissertations

Vibrio cholerae is responsible for the diarrheal disease cholera by producing two major virulence factors: cholera toxin (CT) and toxin-coregulated pilus (TCP). During infection, V. cholerae downregulates its motility genes, which are actively expressed in the environment, and upregulates its virulence genes, which are inactive in the environment. Virulence gene transcription is regulated by the major transcriptional activator, ToxT. ToxT is regulated, in part, by host signals, which in turn, make ToxT active or inactive in respect to virulence gene expression. Host signals include temperature and pH as well as the chemical molecules bicarbonate and bile, which are positive and …

Cell Envelope Modifications By Lcp Family Proteins Of Group B Streptococcus And Virulence Singaling By Peptides Of The Salivaricin Locus Of Streptococcus Pyogenes, Hannah Morrison Rowe

Wayne State University Dissertations

ABSTRACT

CELL ENVELOPE MODIFICATIONS BY LCP FAMILY PROTEINS OF GROUP B STREPTOCOCCUS AND VIRULENCE SIGNALING BY PEPTIDES OF THE SALIVARICIN LOCUS OF STREPTOCOCCUS PYOGENES

by

HANNAH MORRISON ROWE

December 2014

Advisor: Dr. Melody Neely

Major: Immunology and Microbiology

Degree: Doctor of Philosophy

Streptococci are important human and animal pathogens. Group B Streptococcus (GBS) is a zoonotic pathogen that is the leading cause of human neonatal sepsis and meningitis. In order to cause systemic disease GBS must produce a polysaccharide capsule. Capsule expression is controlled in part by the protein CpsA. We demonstrate that deletion of the cpsA gene, or expression …

The Acoustic Emissions Produced By Escherichia Coli During The Growth Cycle, Traci Jane Cox

Theses and Dissertations--Animal and Food Sciences

The objective of this study was to determine if acoustic emissions (AE) generated by three strains of Escherichia Coli (5024-parent strain, 8279-mutant strain and 8279-random/unrelated strain) could be used to differentiate each strain during their growth cycle. An acoustic sensor with an operating range of 35 kHz-100 kHz was inserted into the growth vessel and attached to a selected channel to capture AE data. The growth vessel was loaded with 60 ml of tryptic soy broth (TSB) (0.25% fructose) media with alginate (1.1%) or without alginate and inoculated with 1% (10⁸ CFU/ml) of an E. coli strain. The growth …

Socs1/Socs3 Expression And Virus Replication Of Denv2 And Hsv-1 In Cytokine-Polarized Subsets Of Raw 264.7 Macrophages, Nagarjuna Reddy Cheemarla

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Cytokine activation of macrophages leads to "macrophage polarizatio" The M1 subset is polarized by exposure to lipopolysaccharide (LPS) and interferon-gamma (IFN-γ) and M2 polarized cells develop after exposure to interleukin-4 (IL-4) or IL-13. In this study, the RAW 264.7 murine macrophage cell line was used to study the effect herpes simplex virus-Type I (HSV-1) and Dengue virus serotype-2 (DENV2) infections have on cultures of unpolarized (M0) or polarized subsets. The macrophage subsets were characterized using cluster of differentiation markers CD14 and CD86. Uninfected M1 macrophages showed up regulation in expression of the co-stimulatory factor B7.2 (CD86) compared to expression by …

Development Of A Co-Culture System To Mimic The Transfection Of Hsv-1 From Keratinocytes To Neuronal Cells, David A. Dixon

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To more closely mimic the in vivo progression of HSV-1 a novel in vitro method was created. In this study HEL-30 keratinocytes were infected with a 0.1 MOI of HSV-1 and plated unto a membrane with 8μm diameter pores. The membrane insert was then placed into culture wells that contained Neuro-2a cells (N2A). The neurites from the neuronal cells made cell-to-cell contact with the infected HEL-30 cells and the virus was transmitted into the neuronal cells. To determine if infection occurred in the N2A cells the cells were lysed and the lysate incubated with Vero cells to titrate virus plaque …

White Blood Cell Counts, Parasite Prevalence, And Plasma Cortisol Levels Of Dogs In A County Animal Shelter: Changes Over Days And Impact Of A Program Of Repeated Human Interaction, Emily S. Dudley

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Animal shelter housing is highly stressful for a dog, compromising welfare and leading to undesirable behaviors and unknown health consequences. We documented the changes in circulating numbers of white blood cells, plasma cortisol, and fecal parasite shedding of dogs housed for 10 days at a county animal shelter. White blood cell changes were most prominent on Day 10 after arrival to the shelter. Changes included increased total leukocytes, mature neutrophils, and lymphocytes, with less consistent increases in monocytes and neutrophil to lymphocyte ratio (N:L). Fecal parasite shedding was elevated and not affected by day. Cortisol levels of shelter dogs declined …

Identification Of The Sites Of Action Of Inhibitors Of Mammalian Phospholipase D2 (Pld2) And The Role Of Interacting Protein Partners, Ramya Ganesan

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Phospholipase D (PLD) is a key enzyme for the remodeling of phospholipids in the cell membrane. PLD has been implicated in many physiological functions such as chemotaxis and phagocytosis as well as pathological functions such as ischemia/reperfusion and cancer metastasis. Several small molecule inhibitors of PLD have been recently developed to overcome these pathological effects. We have concentrated on 5-Fluoro-2-Indolyl des-Chlorohalopemide (FIPI) which is an indole derivative of halopemide that inhibits the two mammalian isoforms PLD1 and PLD2. We also concentrate on N-[2-[1-(3-Fluorophenyl)-4-oxo-1,3,-8-triazaspiro[4.5]dec-8-yl]ethyl]-2-naphthalenecarboxamide (NFOT) and N-[2-(4-oxo-1-phenyl-1,3,8-triazaspiro[4,5]dec-8-yl)ethyl]-2-naphthalenecarboxamide (NOPT) that are specific inhibitors of the PLD2 isoform. In spite of knowing their …

Comparison Between Flow Cytometry And Bead Method In Counting Cd4 And Cd8 T Lymphocytes In Mouse Spleen Cells Suspension, Abdulrahman Abdalla Allabidi

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The flow cytometry is gold standard method to count CD4, CD8 human T lymphocytes, and calculate CD8 to CD4 ratio in HIV patients peripheral blood to stage them and monitor their response to treatment. In this study, a comparison was made by counting CD4and CD8 mouse spleen T lymphocytes by flow cytometry, and a method involving antibody coated latex beads. The bead method yielded results comparable to those obtained by flow cytometry. These results indicate that antibody coated beads are suitable to determine CD4 and CD8 + T lymphocytes counts in situation where flow cytometry is not readily available.