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Microbiology

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Articles 181 - 210 of 320

Full-Text Articles in Microbiology

Analysis Of Johne's Disease Elisa Status And Associated Performance Parameters In Irish Dairy Cows, A. E. Kennedy, N. Byrne, A. B. Garcia, Jim O'Mahony, R. G. Sayers Mar 2016

Analysis Of Johne's Disease Elisa Status And Associated Performance Parameters In Irish Dairy Cows, A. E. Kennedy, N. Byrne, A. B. Garcia, Jim O'Mahony, R. G. Sayers

Department of Biological Sciences Publications

Background

Infection with Mycobacterium avium subspecies paratuberculosis (MAP) has been associated with reductions in milk production in dairy cows and sub optimal fertility. The aim of this study was to highlight the production losses associated with testing MAP ELISA positive in Irish dairy cows. Secondary objectives included investigation of risk factors associated with testing MAP ELISA positive. A survey of management practices on study farms was also conducted, with examination of associations between management practices and herd MAP status.

Blood samples were collected from 4188 breeding animals on 22 farms. Samples were ELISA tested using the ID Screen Paratuberculosis Indirect …


Comparing Apples And Oranges?: Next Generation Sequencing And Its Impact On Microbiome Analysis, Adam G. Clooney, Fiona Fouhy, Roy D. Sleator, Aisling O'Driscoll, Stanton Catherine, Paul D. Cotter, Marcus J. Claesson Feb 2016

Comparing Apples And Oranges?: Next Generation Sequencing And Its Impact On Microbiome Analysis, Adam G. Clooney, Fiona Fouhy, Roy D. Sleator, Aisling O'Driscoll, Stanton Catherine, Paul D. Cotter, Marcus J. Claesson

Department of Biological Sciences Publications

Rapid advancements in sequencing technologies along with falling costs present widespread opportunities for microbiome studies across a vast and diverse array of environments. These impressive technological developments have been accompanied by a considerable growth in the number of methodological variables, including sampling, storage, DNA extraction, primer pairs, sequencing technology, chemistry version, read length, insert size, and analysis pipelines, amongst others. This increase in variability threatens to compromise both the reproducibility and the comparability of studies conducted. Here we perform the first reported study comparing both amplicon and shotgun sequencing for the three leading next-generation sequencing technologies. These were applied to …


Changes In Cytoskeleton Proteins In Hsv-1 Infection Of J774a.1 Macrophage Phenotype, Riham Abbas Subahi Jan 2016

Changes In Cytoskeleton Proteins In Hsv-1 Infection Of J774a.1 Macrophage Phenotype, Riham Abbas Subahi

Browse all Theses and Dissertations

The cell cytoskeleton, a unique intracellular matrix found in all eukaryotes, is composed of three main protein structures, microtubules, microlaments and intermediate laments. The cytoskeleton maintains cell shape and internal structures providing mechanical support that facilitates intracellular transport (Parker et al., 2014). Many viruses such as the herpesviruses use the cytoskeleton system of the cell for infectivity (Henry Sum, M. S. 2015). HSV-1 utilizes the cell cytoskeleton in many steps of its life cycle from entry through assembly to egress (Lyman et al., 2008). During infection, HSV-1 viral proteins cause drastic changes and rearrangement of the cellular actin and cell …


Identification Of Protein-Protein Interactions Of Amyotrophic Lateral Sclerosis Associated Protein Tdp-43, Hanoor Sharma Jan 2016

Identification Of Protein-Protein Interactions Of Amyotrophic Lateral Sclerosis Associated Protein Tdp-43, Hanoor Sharma

Browse all Theses and Dissertations

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease caused by progressive degeneration of upper and lower motor neurons in the brain and spinal cord. Multiple mutations are found in some of the proteins associated with ALS, including superoxide dismutase (SOD1), fused in sarcoma (FUS) and trans-activation response DNA-binding protein (TDP-43). TDP-43 is a DNA and RNA binding protein, well conserved, and ubiquitously expressed in all tissues. TDP-43 resides in the nucleus and sometimes shuttles between nucleus and cytoplasm. Mutations in TDP-43 leads to mislocalization of TDP-43 to the cytosol where it was ubiqutinated and hyperphosphsorylated, ultimately leading to neuronal cell …


Synthetic Biology For Autotrophic And Heterotrophic Production Of Ethanol, Nathanael Braselton Jan 2016

Synthetic Biology For Autotrophic And Heterotrophic Production Of Ethanol, Nathanael Braselton

Electronic Theses and Dissertations

Growing energy demand and rising levels of greenhouse gases has put massive strain on the global environment. Alternatives to fossil fuels are being developed in an attempt to curb climate change. Biotechnology has made large strides in order to create a completely renewable energy source by genetically modifying microbes to produce biofuels and other “green” high value compounds. In this thesis project, (1) E. coli ATCC9637 (E. coli W) was genetically modified to produce bioethanol from beet juice which contains mainly sucrose. The ethanol productivity by engineered E. coli W was 18.8 mg/L/H/OD600.
(2) Cyanobacterium Anabaena sp. PCC7120 …


Isolation And Identification Of Bacterial Endosymbionts In The Brooding Brittle Star Amphipholis Squamata, Abbey Rose Tedford Jan 2016

Isolation And Identification Of Bacterial Endosymbionts In The Brooding Brittle Star Amphipholis Squamata, Abbey Rose Tedford

Honors Theses and Capstones

Symbiotic associations with subcuticular bacteria (SCB) have been identified and studied in numerous echinoderms, including the SCB of the brooding brittle star, Amphipholis squamata. These SCB, however, have not been studied using current next generation sequencing technologies. Previous studies on the SCB of A. squamata placed these bacteria in the genus Vibrio (γ-Proteobacteria), but subsequent studies suggested that the SCB are primarily composed of α-Proteobacteria. The present study examines the taxonomic composition of SCB associated with A. squamata from the Northwest Atlantic. DNA was extracted using a CTAB protocol and 16S rRNA sequences were amplified …


The Expression Of Aryl Hydrocarbon Receptor In Raw 264.7 Macrophages In The Presence Of Socs1 Peptide And Socs3 Peptide Mimetic And Cells Infected With Hsv-1, Maher Salem Alwethaynani Jan 2016

The Expression Of Aryl Hydrocarbon Receptor In Raw 264.7 Macrophages In The Presence Of Socs1 Peptide And Socs3 Peptide Mimetic And Cells Infected With Hsv-1, Maher Salem Alwethaynani

Browse all Theses and Dissertations

Macrophages play a crucial role for our immune system and protect our body from infection. Suppressor of cytokine signaling (SOCS) proteins negatively regulate cytokine receptor and TLRs. The aryl hydrocarbon receptor (AhR) also performs an important role in immunity. This study investigated the changes in expression of AhR in RAW 264.7 macrophage cells after the addition of SOCS1 and SOCS3 peptide mimetics and also examined AhR expression in RAW 264.7 macrophage cells before and after the addition of HSV-1 RAW 264.7 murine macrophage cell lines which are from male BALB/c mice were used in this study. The addition of the …


Cell Viability, Cytoskeleton Organization And Cytokines Secretion Of Raw 264.7 Macrophages Exposed To Gram-Negative Bacterial Components, Ali Awadh Alshehri Jan 2016

Cell Viability, Cytoskeleton Organization And Cytokines Secretion Of Raw 264.7 Macrophages Exposed To Gram-Negative Bacterial Components, Ali Awadh Alshehri

Browse all Theses and Dissertations

Macrophages play an important role in innate immunity by controlling cellular responses. In this study, the effects of gram-negative bacterial components (Flagellin, lipoprotein, lipopolysaccharides (LPS), outer membrane proteins-A (OMP-A) and peptidoglycan) were determined on cell viability, morphology, cytoskeletal filament and cytokines secretion of murine RAW 264.7 macrophages at 24 hours. The effect of LPS, flagellin and peptidoglycan from gram negative bacteria on viability murine RAW 264.7 macrophages were evaluated using different concentrations (1, 5 and 10 µg/ml). Cells stimulated with LPS displayed ~ 2-fold decrease (P=0.001) in cell viability compared to control cells at 24 hours whereas cells stimulated with …


Phylogenetic Investigation Of Enteric Bovine Coronavirus In Ireland Reveals Partitioning Between European And Global Strains, Lynda Gunn, P. J. Collins, M. J. O'Connell, Helen O'Shea Dec 2015

Phylogenetic Investigation Of Enteric Bovine Coronavirus In Ireland Reveals Partitioning Between European And Global Strains, Lynda Gunn, P. J. Collins, M. J. O'Connell, Helen O'Shea

Department of Biological Sciences Publications

Background

Bovine coronavirus is a primary cause of neonatal calf diarrhea worldwide, and is also associated with acute diarrhea in adult cattle during the winter season. There are no reports on molecular characterization of bovine coronavirus in Ireland, and little data exists apart from serological studies.

Findings

In this study, 11 neonatal (mean age 9 days) calf BCoV strains from the south of Ireland were collected over a one year period and characterized using molecular methods. The spike gene which encodes a protein involved in viral entry, infectivity and immune response shows the most variability amongst the isolates and was …


A Tail Of Two Phages: Genomic And Functional Analysis Of Listeria Monocytogenes Phages Vb_Lmos_188 And Vb_Lmos_293 Reveal The Receptor-Binding Proteins Involved In Host Specificity, Aidan Casey, Kieran Jordan, Horst Neve, Aidan Coffey, Olivia Mcauliffe Oct 2015

A Tail Of Two Phages: Genomic And Functional Analysis Of Listeria Monocytogenes Phages Vb_Lmos_188 And Vb_Lmos_293 Reveal The Receptor-Binding Proteins Involved In Host Specificity, Aidan Casey, Kieran Jordan, Horst Neve, Aidan Coffey, Olivia Mcauliffe

Department of Biological Sciences Publications

The physical characteristics of bacteriophages establish them as viable candidates for downstream development of pathogen detection assays and biocontrol measures. To utilize phages for such purposes, a detailed knowledge of their host interaction mechanisms is a prerequisite. There is currently a wealth of knowledge available concerning Gram-negative phage-host interaction, but little by comparison for Gram-positive phages and Listeria phages in particular. In this research, the lytic spectrum of two recently isolated Listeria monocytogenes phages (vB_LmoS_188 and vB_LmoS_293) was determined, and the genomic basis for their observed serotype 4b/4e host-specificity was investigated using comparative genomics. The late tail genes of these …


Isolation & Characterization Of Bacteria In The Built Environment: Measuring The Effect Of Pharmaceuticals On Growth, Amanda V. Finck, Kelly J. Digeronimo, Nene S. Sy, Zakiya Whatley Oct 2015

Isolation & Characterization Of Bacteria In The Built Environment: Measuring The Effect Of Pharmaceuticals On Growth, Amanda V. Finck, Kelly J. Digeronimo, Nene S. Sy, Zakiya Whatley

Student Publications

This work reports the isolation and characterization of bacteria from the built environment at Gettysburg College in Gettysburg, PA. Surfaces of a water fountain on campus were swabbed and serially streaked to isolate multiple bacteria on R2A agar. Following multiple rounds of growth, the unknown microbial candidates were narrowed to two visibly­distinct organisms. Morphological characterization and phylogenetic identification based on 16S rDNA sequencing revealed that the isolates were Chryseobactierum hispalense and Microbacterium maritypicum. We report synergistic biofilm formation between Chryseobactierum hispalense and Microbacterium maritypicum. The contamination of drinking water with varying levels of personal care products and pharmaceuticals (PCPPs) is …


Isolation And Epidemiological Analysis Of Verotoxigenic E. Coli From Patients With Acute Gastroenteritis: A Prospective Study Aiming To Reduce The Burden Of Infection In The Cork Region., Shirley Ross Jun 2015

Isolation And Epidemiological Analysis Of Verotoxigenic E. Coli From Patients With Acute Gastroenteritis: A Prospective Study Aiming To Reduce The Burden Of Infection In The Cork Region., Shirley Ross

Masters

Verotoxigenic Escherichia coli (VTEC) is a serious gastrointestinal pathogen associated with morbidity and mortality in the first world, as accentuated by the O104 VTEC outbreak in Germany in 2011. Molecular detection of Verotoxin (VT) has increased the detection of VTEC across Europe however, Ireland still has the highest incidence and isolation is still a key step in the confirmation of infection and the control and prevention of outbreaks. Currently no standard protocol exists for the detection, isolation and characterisation of non-O157 VTEC and it is feared that due to this that the prevalence of VTEC is under-reported. This body of …


Draft Genome Sequences Of Six Different Staphylococcus Epidermidis Clones, Isolated Individually From Preterm Neonates Presenting With Sepsis At Edinburgh's Royal Infirmary, Paul Walsh, M. Bekaert, J. Carroll, T. Manning, B. Kelly, A. O'Driscoll, X. Lu, C. Smith, P. Dickinson, K. Templeton, P. Ghazal, Roy D. Sleator May 2015

Draft Genome Sequences Of Six Different Staphylococcus Epidermidis Clones, Isolated Individually From Preterm Neonates Presenting With Sepsis At Edinburgh's Royal Infirmary, Paul Walsh, M. Bekaert, J. Carroll, T. Manning, B. Kelly, A. O'Driscoll, X. Lu, C. Smith, P. Dickinson, K. Templeton, P. Ghazal, Roy D. Sleator

Department of Biological Sciences Publications

Herein, we report the draft genome sequences of six individual Staphylococcus epidermidis clones, cultivated from blood taken from different preterm neonatal sepsis patients at the Royal Infirmary, Edinburgh, Scotland, United Kingdom.


Combating Infectious Diseases In Aquaculture With An Original Probiotic Product, Meagan Hamblin, Saebom Sohn, Christine Ahn Dao, Marta Gomez-Chiarri, David R. Nelson, David Worthen, David Rowley May 2015

Combating Infectious Diseases In Aquaculture With An Original Probiotic Product, Meagan Hamblin, Saebom Sohn, Christine Ahn Dao, Marta Gomez-Chiarri, David R. Nelson, David Worthen, David Rowley

Senior Honors Projects

Oyster production in Rhode Island accounts for over $2.5 million in annual revenue, making it the top aquaculture product in the state. However, larval tank infections significantly constrain production and create substantial economic losses for commercial hatcheries. In most cases antibiotics may not be used to prevent or treat larval tank infections. A probiotic, or beneficial microbe which competes with pathogens, is a safer and “green” approach to preventing infections. Vibriosis, a common cause of oyster larval mortality, is the result of Vibrio species infections. Previous studies have shown that a native Rhode Island microbe, Bacillus pumilus RI06-95, protects oyster …


Functional Screening Of The Cronobacter Sakazakii Baa-894 Genome Reveals A Role For Prop (Esa_02131) In Carnitine Uptake, Audrey Feeney, Roy D. Sleator Apr 2015

Functional Screening Of The Cronobacter Sakazakii Baa-894 Genome Reveals A Role For Prop (Esa_02131) In Carnitine Uptake, Audrey Feeney, Roy D. Sleator

Department of Biological Sciences Publications

Cronobacter sakazakii is a neonatal pathogen responsible for up to 80% of fatalities in infected infants. Low birth weight infants and neonates infected with C. sakazakii suffer necrotizing enterocolitis, bacteraemia and meningitis. The mode of transmission most often associated with infection is powdered infant formula (PIF) which, with an aw of ∼0.2, is too low to allow most microorganisms to persist. Survival of C. sakazakii in environments subject to extreme hyperosmotic stress has previously been attributed to the uptake of compatible solutes including proline and betaine. Herein, we report the construction and screening of a C. sakazakii genome bank and …


Long-Term Impacts Of Disturbance On Nitrogen-Cycling Bacteria In A New England Salt Marsh, Anne E. Bernhard, Courtney Dwyer, Adrian Idrizi, Geoffrey Bender, Rachel Zwick Feb 2015

Long-Term Impacts Of Disturbance On Nitrogen-Cycling Bacteria In A New England Salt Marsh, Anne E. Bernhard, Courtney Dwyer, Adrian Idrizi, Geoffrey Bender, Rachel Zwick

Biology Faculty Publications

Recent studies on the impacts of disturbance on microbial communities indicate communities show differential responses to disturbance, yet our understanding of how different microbial communities may respond to and recover from disturbance is still rudimentary. We investigated impacts of tidal restriction followed by tidal restoration on abundance and diversity of denitrifying bacteria, ammonia-oxidizing bacteria (AOB), and ammonia-oxidizing archaea (AOA) in New England salt marshes by analyzing nirS and bacterial and archaeal amoA genes, respectively. TRFLP analysis of nirS and betaproteobacterial amoA genes revealed significant differences between restored and undisturbed marshes, with the greatest differences detected in …


Immunotherapy For Human Breast Cancer, Nasrah Ali Al Kamal Jan 2015

Immunotherapy For Human Breast Cancer, Nasrah Ali Al Kamal

Browse all Theses and Dissertations

Al Kamal, Nasrah. M.S. Program of Microbiology and Immunology, Wright State University, 2015.Immunotherapy for Human Breast Cancer. The study focuses on the methodologies that are used in breast cancer therapy. The review finds major evolutions of these methods and the influence they have made on the increased survival rates in cancer patients. There is also a projection of the processes that are involved in the therapy practices and the way the protocols have been improved over time. The various stages of cancer treatment project the various aspects of better performance articulations in the therapy sector. There is also reference to …


Atmospheric Cold Plasma As A Tool For Microbiological Control, Dana Ziuzina Jan 2015

Atmospheric Cold Plasma As A Tool For Microbiological Control, Dana Ziuzina

Doctoral

Outbreaks of foodborne human illnesses resulting from contaminated raw or minimally processed fruits and vegetables have been widely reported globally. The microbiological challenges associated with fresh produce are diverse and respond differently to minimal processing technologies. Atmospheric cold plasma is a relatively new technology and represents a potential alternative to traditional methods for decontamination of foods. The objective of this work was to determine the influence of extrinsic atmospheric cold plasma (ACP) treatment control parameters and to optimize treatment parameters for decontamination with respect to different forms of key safety challenges pertinent to fresh produce.

The optimisation studies demonstrated that …


The Impact Of Hsv-1 Infection On Cell Viability, Morphology, And Cd Markers Expression By Unpolarized And Cytokine-Polarized J774a.1 Mouse Macrophages, Sarah Saad Alsharif Jan 2015

The Impact Of Hsv-1 Infection On Cell Viability, Morphology, And Cd Markers Expression By Unpolarized And Cytokine-Polarized J774a.1 Mouse Macrophages, Sarah Saad Alsharif

Browse all Theses and Dissertations

Macrophages play an important role in the immune system, particularly in neutralizing pathogens via phagocytosis and the production of multiple cytokines and chemokines that control infection after exposure to specific stimuli. Macrophages exhibit two different phenotypes, M1 and M2. This study evaluated the role of Suppressors of cytokine signaling (SOCS)1 and SOCS3 on Herpes Simplex Virus (HSV-1) infection of polarized macrophages, cell viability, cell morphology, and the expression of cell surface CD markers. I hypothesized that J774A.1 murine macrophages cells in the naive state (M0), and M1 and M2 phenotypes would display differences in CD markers CD80,CD163, and CD200R, cell …


The Use Of Antibody-Coated Latex Beads To Determine Single Positive And Double Positive Mouse Spleen Cells Expressing Cd5 And/Or Cd19 Glycoproteins, Abdulrazzag Abdulaziz Othman Jan 2015

The Use Of Antibody-Coated Latex Beads To Determine Single Positive And Double Positive Mouse Spleen Cells Expressing Cd5 And/Or Cd19 Glycoproteins, Abdulrazzag Abdulaziz Othman

Browse all Theses and Dissertations

Flow cytometry is the standard method used to diagnose, stage, and monitor patients' response to the treatment given by counting the numbers of CD5, CD19 and CD5+ CD19+ B lymphocytes. In this study, a comparison was done between numbers of single CD5+, single CD19+ and dual CD5+ CD19+ mouse spleen B lymphocytes using flow cytometry and antibody-latex beads. The bead method involved antibody-coated latex bead and yielded results similar to those of flow cytometry. For cells exhibiting both markers (CD5+ CD19+), the bead method used antibody-coated beads of two different colors yielded similar results to those of flow cytometry results. …


Structural Insights Into The Architecture Of The Hyperthermophilic Fusellovirus Ssv1, Kenneth M. Stedman, Melissa Deyoung, Mitul Saha, Michael B. Sherman, Marc C. Morais Nov 2014

Structural Insights Into The Architecture Of The Hyperthermophilic Fusellovirus Ssv1, Kenneth M. Stedman, Melissa Deyoung, Mitul Saha, Michael B. Sherman, Marc C. Morais

Biology Faculty Publications and Presentations

The structure and assembly of many icosahedral and helical viruses are well-characterized. However, the molecular basis for the unique spindle-shaped morphology of many viruses that infect Archaea remains unknown. To understand the architecture and assembly of these viruses, the spindle-shaped virus SSV1 was examined using cryo-EM, providing the first 3D-structure of a spindle-shaped virus as well as insight into SSV1 biology, assembly and evolution. Furthermore, a geometric framework underlying the distinct spindle-shaped structure is proposed.


The Exometabolome Of Clostridium Thermocellum Reveals Overflow Metabolism At High Cellulose Loading, Evert K. Holwerda, Philip G. Thorne, Daniel G. Olson, Daniel Amador-Noguez, Nancy L. Engle, Timothy J. Tschaplinski, Johannes P. Van Dijken, Lee R. Lynd Oct 2014

The Exometabolome Of Clostridium Thermocellum Reveals Overflow Metabolism At High Cellulose Loading, Evert K. Holwerda, Philip G. Thorne, Daniel G. Olson, Daniel Amador-Noguez, Nancy L. Engle, Timothy J. Tschaplinski, Johannes P. Van Dijken, Lee R. Lynd

Dartmouth Scholarship

BackgroundClostridium thermocellum is a model thermophilic organism for the production of biofuels from lignocellulosic substrates. The majority of publications studying the physiology of this organism use substrate concentrations of ≤10 g/L. However, industrially relevant concentrations of substrate start at 100 g/L carbohydrate, which corresponds to approximately 150 g/L solids. To gain insight into the physiology of fermentation of high substrate concentrations, we studied the growth on, and utilization of high concentrations of crystalline cellulose varying from 50 to 100 g/L by C. thermocellum. .


Watts Cooking: Using A Microwave To Prepare Bacterial Media For Inquiry-Based Experiments, Judith A. Scheppler Oct 2014

Watts Cooking: Using A Microwave To Prepare Bacterial Media For Inquiry-Based Experiments, Judith A. Scheppler

Staff Publications & Research

Microbiology provides an excellent opportunity to capture student interest, encourage exploration, and to begin the development of research skills. With a low power microwave, similar to the type found in homes, and a short list of materials easily obtainable and/or found in many biology laboratories, you can begin to open this exciting world to your life science and biology classes. Microwaves are available at very reasonable prices, and can substitute for a much more expensive laboratory autoclave. Your students can choose and design inquiry investigations as well as learn basic laboratory techniques.


Enhanced Expression Of Codon Optimized Mycobacterium Avium Subsp. Paratuberculosis Antigens In Lactobacillus Salivarius, Christopher D. Johnston, John P. Bannatine, Rodney Govender, Lorraine Endersen, Daniel Pletzer, Helge Weingart, Aidan Coffey, Jim O'Mahony, Roy D. Sleator Sep 2014

Enhanced Expression Of Codon Optimized Mycobacterium Avium Subsp. Paratuberculosis Antigens In Lactobacillus Salivarius, Christopher D. Johnston, John P. Bannatine, Rodney Govender, Lorraine Endersen, Daniel Pletzer, Helge Weingart, Aidan Coffey, Jim O'Mahony, Roy D. Sleator

Department of Biological Sciences Publications

It is well documented that open reading frames containing high GC content show poor expression in A+T rich hosts. Specifically, G+C-rich codon usage is a limiting factor in heterologous expression of Mycobacterium avium subsp. paratuberculosis (MAP) proteins using Lactobacillus salivarius. However, re-engineering opening reading frames through synonymous substitutions can offset codon bias and greatly enhance MAP protein production in this host. In this report, we demonstrate that codon-usage manipulation of MAP2121c can enhance the heterologous expression of the major membrane protein (MMP), analogous to the form in which it is produced natively by MAP bacilli. When heterologously over-expressed, antigenic determinants …


Transcriptional Regulation Of Sinorhizobium Meliloti Cell Cycle-Related Genes In The Δcbra Mutant And Root Nodules Of Medicago Sativa, Corey S. Hazekamp Aug 2014

Transcriptional Regulation Of Sinorhizobium Meliloti Cell Cycle-Related Genes In The Δcbra Mutant And Root Nodules Of Medicago Sativa, Corey S. Hazekamp

Graduate Masters Theses

Sinorhizobium meliloti is a Gram-negative alphaproteobacterium and nitrogen-fixing symbiont, which undergoes a novel cell cycle modification during its' host-microbe interaction. I intend to monitor the transcriptional regulation of cell cycle-related genes during free-loving growth, in addition to monitoring their expression during symbiosis. Using genes known to be regulated by CtrA in C. crescentus or predicted to be regulated by CtrA in S. meliloti, I aim to show how certain cell cycle genes are regulated in S. meliloti. In C. crescentus, CtrA acts as a transcription factor that is active when phosphorylated and inactive when not phosphorylated. In …


The Innate Immune Response In Eisenia Fetida To Microbial Challenges, Aaron Schindler Aug 2014

The Innate Immune Response In Eisenia Fetida To Microbial Challenges, Aaron Schindler

Journal of Undergraduate Research at Minnesota State University, Mankato

The common earthworm, Eisenia fetida, exhibits a rudimentary immune system. The earthworm needs cellular and chemical responses against a constant microbial exposure from its natural environment. Some cellular and chemical responses are found in the coelomic fluid and have been shown to demonstrate anti-microbial characteristics. This project uses microscopy and modified staining techniques to differentiate and categorize the cellular components found in the coelomic fluid. Following a microbial challenge by Klebsiella pneumoniae, an inflammatory response was initiated. Six groups of earthworms were injected with 0.05 ml of 1.0 x 106 cfu /ml K. pneumoniae on day one and tested over …


Characterization Of A Putative Cephalotoxin From The Hemocytes Of Euprymna Scolopes, Jessie E. Scott May 2014

Characterization Of A Putative Cephalotoxin From The Hemocytes Of Euprymna Scolopes, Jessie E. Scott

University Scholar Projects

Many organisms have beneficial microbial symbionts, and complex interactions between the immune system and the bacteria must occur to allow these symbioses to persist. The host immune system must recognize and preferentially tolerate the beneficial microorganisms, while simultaneously eliminating harmful pathogens. The Hawaiian bobtail squid, Euprymna scolopes, is a model organism for host-microbe interactions because of the unique light organ symbiosis. Hemocytes, the squid’s primary immune cell, infiltrate and patrol the light organ and continuously interact with the symbiont Vibrio fischeri. Using this model, several innate immunity genes have been shown to be differentially expressed in the hemocytes …


Combined Metagenomic And Phenomic Approaches Identify A Novel Salt Tolerance Gene From The Human Gut Microbiome, Eamon Culligan, Julian R. Marchesi, Colin Hill, Roy D. Sleator Apr 2014

Combined Metagenomic And Phenomic Approaches Identify A Novel Salt Tolerance Gene From The Human Gut Microbiome, Eamon Culligan, Julian R. Marchesi, Colin Hill, Roy D. Sleator

Department of Biological Sciences Publications

In the current study, a number of salt-tolerant clones previously isolated from a human gut metagenomic library were screened using Phenotype MicroArray (PM) technology to assess their functional capacity. PM's can be used to study gene function, pathogenicity, metabolic capacity and identify drug targets using a series of specialized microtitre plate assays, where each well of the microtitre plate contains a different set of conditions and tests a different phenotype. Cellular respiration is monitored colorimetrically by the reduction of a tetrazolium dye. One clone, SMG 9, was found to be positive for utilization/transport of L-carnitine (a well-characterized osmoprotectant) in the …


Colonization Of Intestinal Pathogen Changes The Gut Microbiota, Kaitlyn Shondelmyer Apr 2014

Colonization Of Intestinal Pathogen Changes The Gut Microbiota, Kaitlyn Shondelmyer

Senior Honors Theses

Enterohemorrhagic Escherechia coli is a serious human pathogen causing bloody diarrhea and hemolytic uremic syndrome. It is difficult to study in animal models, but pathogenesis may be modeled in mice with the similar murine pathogen, Citrobacter rodentium. C. rodentium does not cause disease in streptomycin-treated mice, suggesting that it is competition with other facultative anaerobes that triggers pathogenesis. Streptomycin-treated mice were co-colonized with C. rodentium and a commensal E. coli strain. The intestinal microbiota of each group was observed over a 15-day period using quantitative PCR. Colon weights were also measured over the same period. Results indicate that the …


Transcriptome Analysis Of Listeria Monocytogenes Exposed To Biocide Stress Reveals A Multi-System Response Involving Cell Wall Synthesis, Sugar Uptake, And Motility, Aidan Casey, Edward M. Fox, Stephan Schmitz-Esser, Aidan Coffey, Olivia Mcauliffe, Kieran Jordan Feb 2014

Transcriptome Analysis Of Listeria Monocytogenes Exposed To Biocide Stress Reveals A Multi-System Response Involving Cell Wall Synthesis, Sugar Uptake, And Motility, Aidan Casey, Edward M. Fox, Stephan Schmitz-Esser, Aidan Coffey, Olivia Mcauliffe, Kieran Jordan

Department of Biological Sciences Publications

Listeria monocytogenes is a virulent food-borne pathogen most often associated with the consumption of “ready-to-eat” foods. The organism is a common contaminant of food processing plants where it may persist for extended periods of time. A commonly used approach for the control of Listeria monocytogenes in the processing environment is the application of biocides such as quaternary ammonium compounds. In this study, the transcriptomic response of a persistent strain of L. monocytogenes (strain 6179) on exposure to a sub-lethal concentration of the quaternary ammonium compound benzethonium chloride (BZT) was assessed. Using RNA-Seq, gene expression levels were quantified by sequencing …