Microbiology Commons^™

Identification Of Factors That Promote The Growth Of Dormant Mycobacterium Avium Subsp. Paratuberculosis, Thu Minh Cao

All Graduate Theses, Dissertations, and Other Capstone Projects

Johne's disease, which is caused by the acid-fast bacterium Mycobacterium avium subspecies paratuberculosis (Mpt), is a chronic, inflammatory intestinal disease that primarily affects ruminants. This disease has a significant effect on the economics of dairy farming. Mpt has a remarkable ability to survive in host tissues for 2-6 years without producing any signs of infection. However, the reliability of diagnostic techniques is limited only to those animals with clinical disease. This may be due to the entry of the organism into a dormant state, which has been reported for other mycobacteria. Reversion to the actively growing state (resuscitation) would improve …

Antimicrobial Activity, Cytotoxicity And Phytochemical Analyses Of Rhus Aromatica, Rhus Glabra And Sanguinaria Canadensis Native To South Dakota, Gitanjali Nandakafle

Electronic Theses and Dissertations

A total of twenty five South Dakota native medicinal plants were screened against enterotoxigenic Escherichia coli using a disk diffusion assay. Out of these 25 plants, three plants Rhus aromatica, Rhus glabra and Sanguinaria canadensis demonstrated the highest bacterial inhibition. The minimum inhibitory concentrations (MIC) of these plant extracts were determined using a bacterial enumeration assay. Alamar Blue in vitro cytotoxicity test showed that all extracts have some toxic effect to porcine intestinal epithelial cell lines. Phytochemical analysis of these plant extracts indicated the presence high concentration of flavonoids and condensed tannins in R. aromatica and that R. glabra contained …

Transcriptional Regulation Of The Acetone Carboxylase Operon Via Two-Component Signal Transduction In Helicobacter Pylori, Vanessa H. Quinlivan-Repasi

Dissertations, Theses, and Masters Projects

No abstract provided.

Establishment Of A Quiescent Infection Of Hsv-1 In L929 Fibroblasts Using A Mitotic Inhibitor And Ifn-Γ, Neelam V. Shinde

Browse all Theses and Dissertations

The goal for this study was to determine if a quiescent infection of HSV-1 could be induced in murine fibroblasts L929 by treating them with the anti-mitotic agent 5-fluoro 2'deoxy uridine (FUDR) alone and with interferon-γ. Since neurons are post-mitotic and exhibit a lower metabolic rate than other cells, fibroblasts were treated with FUDR to induce a post-mitotic state. The cell cycle arrest of fibroblasts would decrease the thymidylate metabolism and impair HSV-1 replication. An evaluation of cytopathic effects of FUDR was used to determine the optimal concentration which arrests cell growth and inhibits viral replication. Image J program developed …

Q-Ve-Oph, A Control Caspase Inhibitor For Analyzing Neuronal Death, Rebecca L. Bricker

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Sarin is a neurotoxin that has been used in terrorist attacks in Japan and is a potential bioterrorist weapon. It induces seizures by affecting the regulation of neurotransmitters in the brain. Seizures are directly correlated to neuronal damage. Two types of neuronal damage that can occur are apoptosis and necrosis. One of the main regions of the brain where neuronal death occurs is the hippocampus, which is involved in memory. Victims showed chronic decline of memory loss 3 and 7 years after the Tokyo's terrorist attack incident. There are treatments available that can break down sarin or can block the …

The Effects Of Enteropathogenic And Commensal Escherichia Coli On Tight Junction Permeability, Hilary Kaye Allen

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The intestinal mucosa maintains a barrier between materials from the external environment and the internal environment of the host. Disruption of the gut wall integrity is involved in the development of various intestinal diseases, such as Irritable Bowel Syndrome (IBS) and Crohn's disease. The intestinal mucosa is lined with epithelial cells that are connected by tight junctions, the intercellular junctions that form a selectively permeable barrier between paracellular pathways. Enteric pathogens, such as enteropathogenic Escherichia coli (EPEC), can disrupt the tight junctions of epithelial cells by altering the cellular cytoskeleton or by directly affecting tight junction proteins. Commensal Escherichia coli …

Mhc Class I Expression In Murine Fibroblast And Keratinocyte Cell Lines During The First Twenty-Four Hours Of Infection With Herpes Simplex Virus-1 (Hsv-1), Prasanthi Kumchala

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The hypothesis of this study is: HSV-1 infection of murine fibroblasts and keratinocytes inhibits expression of MHC class I molecules during first 24 hours of infection. IFN-γ pretreatment of fibroblasts protected the cells from virus-induced inhibition of MHC class I expression, but did not protect keratinocytes. Herpesviruses are known for their ability to establish persistent infections. Herpesviruses exert many different ways to suppress host defense mechanisms. One such way is by down regulating expression of the major histocompatibility complex I (MHC I) molecules in infected cells. Epidermal cells such as keratinocytes are the major sites for herpes simplex virus type …

The Effects Of Hsv-1 Challenge On Polarized Murine Macrophages: An In Vitro Model Using The J774a.1 Murine Macrophage Cell Line, Adam Craig Reichard

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In our current study we examined the effects of HSV-1 challenge on J774A.1 macrophages polarized to either a proinflammatory (M1) or anti-inflammatory (M2) phenotype. Polarized J774A.1 macrophages were characterized using CD14-CD86 and SOCS1-SOCS3 expression levels. SOCS proteins are a family of proteins that are capable of inhibiting cytokine-signaling pathways. HSV-1 up regulates expression of SOCS1 protein levels in infected cells, inhibiting the ability of infected cells to produce proinflammatory products (Nowoslawski Akhtar and Benveniste, 2011). This study shows that signals within the microenvironment play a greater role in macrophage polarization, and SOCS1-SOCS3 expression levels, than does HSV-1 challenge. M1 macrophages …

Suppressor Of Cytokine Signaling (Socs) 1 & 3 Expression In Hsv-1- Infected And Interferon-Γ-Treated Neuro-2a Cells, Melinda Jones

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This study examined the effects of HSV-1 infection and IFN-γ treatment on Neuro-2A cells. HSV-1 induces expression of SOCS1 and SOCS3 in infected cells, inhibiting the ability of these cells to produce the pro inflammatory, antiviral cytokine IFN-γ (Nowoslawski and Benveniste, 2011). SOCS1 and SOCS3 levels were determined in IFN-γ-treated cells, virus-infected cells, and cells that were both IFN-γ-treated and virus-infected. Results were compared with untreated, uninfected control cells. Flow cytometry data analysis showed a slight decrease in SOCS1 and SOCS3 protein levels in cells treated with IFN-γ for 6 hours compared to control cells. A significant decrease in SOCS1 …

The Construction Of A Plasmid For Detecting The Pathway Of Arginine Metabolism In Human Macrophages: A Real-Time Assessment Of Macrophage Polarity, Benjamin A. Holmes

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Macrophages are "first responders", innate immune system cells which quickly arrive to a site of infection and injury, consuming cell debris and foreign matter and recruiting other immune system cells to the area. While historically they have been thought to react uniformly to all challenges, the discovery of toll-like receptors has shown that macrophages actually work closely with the adaptive immune system in fine-tuning the immune response. Furthermore, it has recently been discovered that macrophages can become polarized to one of two subtypes-M1 or M2.

M1 macrophages are efficient producers of reactive oxygen species, nitrogen intermediates, and inflammatory cytokines. They …

Investigation Of The Membrane Interactions Of Mycobacterium Tuberculosis Secreted Factors Esat-6 And Cfp-10, Joaquin A. De Leon

Open Access Theses & Dissertations

Mycobacterium tuberculosis is the causative agent of the infectious disease tuberculosis, infecting about one-third of human race. Infections are not vast in the United States when compared to many other countries, yet many cases seen in the United States are of those who have immigrated to the United States. The Hispanic/Latino population in the United States contributes to a large fraction of those infected with tuberculosis in the United States. During this study we purified recombinant Mycobacterium tuberculosis secreted factors ESAT-6 and CFP-10 from Escherichia coli. Here we have introduced a method in which we can refold and purify …

Survey Of Antibiotic Resistant Bacteria In Fish Gut Collected From Selected Sites., Ahmed Mustafa, Hasina Karki, Arlis Lamaster, Bob Gillespie, Shree Dhawale

Ahmed Mustafa Dr.

No abstract provided.

Do Larval Traits Re-Evolve? Evidence From The Embryogenesis Of A Direct-Developing Salamander, Plethodon Cinereus, Ryan Kerney, David Blackburn, Hendrik Muller, James Hanken

Ryan Kerney

Recent molecular phylogenies suggest the surprising reacquisition of posthatching metamorphosis within an otherwise directdeveloping clade of lungless salamanders (family Plethodontidae). Metamorphosis was long regarded as plesiomorphic for plethodontids, yet the genus Desmognathus, which primarily includes metamorphosing species, is now nested within a much larger clade of direct-developing species. The extent to which the putative reacquisition of metamorphosis in Desmognathus represents a true evolutionary reversal is contingent upon the extent to which both larva-specific features and metamorphosis were actually lost during the evolution of direct development. In this study we analyze development of the hyobranchial skeleton, which is dramatically remodeled during …

The Genome Of Pelobacter Carbinolicus Reveals Surprising Metabolic Capabilities And Physiological Features, Muktak Aklujkar, Shelley Haveman, Raymond Didonato, Olga Chertkov, Cliff Han, Miriam Land, Peter Brown, Derek Lovley

Muktak Aklujkar

Background: The bacterium Pelobacter carbinolicus is able to grow by fermentation, syntrophic hydrogen/formate transfer, or electron transfer to sulfur from short-chain alcohols, hydrogen or formate; it does not oxidize acetate and is not known to ferment any sugars or grow autotrophically. The genome of P. carbinolicus was sequenced in order to understand its metabolic capabilities and physiological features in comparison with its relatives, acetate-oxidizing Geobacter species.

Results: Pathways were predicted for catabolism of known substrates: 2,3-butanediol, acetoin, glycerol, 1,2-ethanediol, ethanolamine, choline and ethanol. Multiple isozymes of 2,3-butanediol dehydrogenase, ATP synthase and [FeFe]-hydrogenase were differentiated and assigned roles according to their …

Adaption Of Synechococcus Sp. Iu 625 To Growth In The Presence Of Mercuric Chloride, Tin-Chun Chu, Sean Murray, Jennifer Todd, Winder Perez, Jonathan Yarborough, Chiedozie Okafor, Lee Lee

Tin-Chun Chu, Ph.D.

No abstract provided.

Comparative Genomic Analysis Of Geobacter Sulfurreducens Kn400, A Strain With Enhanced Capacity For Extracellular Electron Transfer And Electricity Production, Jessica Butler, Nelson Young, Muktak Aklujkar, Derek Lovley

Muktak Aklujkar

Background: A new strain of Geobacter sulfurreducens, strain KN400, produces more electrical current in microbial fuel cells and reduces insoluble Fe(III) oxides much faster than the wildtype strain, PCA. The genome of KN400 was compared to wildtype with the goal of discovering how the network for extracellular electron transfer has changed and how these two strains evolved.

Results: Both genomes were re-annotated, resulting in 14 fewer genes (net) in the PCA genome; 28 fewer (net) in the KN400 genome; and ca. 400 gene start and stop sites moved. 96% of genes in KN400 had clear orthologs with conserved synteny in …

Molecular Action Of 1,2,4-Trioxolanes In Plasmodium Falciparum, R. A. Cooper, C. L. Hartwig, E. Lauterwasser, S. Mahajan, M. Hoke, A. Renslo

Roland A. Cooper

No abstract provided.

Diversity Of Bacteria And Archaea In Hypersaline Sediment From Death Valley National Park, California, J.-S. Kim, M. Makama, J. Petito, N.-H. Park, Frederick M. Cohan, R. S. Dungan

Frederick M. Cohan

No abstract provided.

The Variable Subdomain Of Escherichia Coli Seca Functions To Regulate Seca Atpase Activity And Adp Release, Sanchaita Das, Lorry M. Grady, Jennifer Michtavy, Yayan Zhou, Frederick M. Cohan, Manju M. Hingorani, Donald B. Oliver

Frederick M. Cohan

No abstract provided.

Diversity Of Bacteria And Archaea In Hypersaline Sediment From Death Valley National Park, California, J.-S. Kim, M. Makama, J. Petito, N.-H. Park, Frederick M. Cohan, R. S. Dungan

Frederick M. Cohan

No abstract provided.