Microbiology Commons^™

Modeling Radiation Effectiveness For Inactivation Of Bacillus Spores, Emily A. Knight

Theses and Dissertations

This research models and analyzes the inactivation of Bacillus spores following a radiation exposure and the process enacted by the Bacillus spore to repair the resulting damage. Irradiation of a spore and the medium surrounding the spore induces chemical reactions that produce reactive oxygen species (ROS). This research will consider the reaction- diffusion of these ROS throughout the spore. These ROS can react with the spore's DNA and enzymes to degrade them to such an extent that the DNA cannot be repaired or replicated, thus causing spore death. In order to survive a dose of radiation, a spore must repair …

Metalloregulation Of Helicobacter Pylori Physiology And Pathogenesis, Kathryn P. Haley, Jennifer A. Gaddy

Peer Reviewed Articles

Helicobacter pylori is a Gram-negative spiral-shaped bacterium that colonizes over half of the world's population. Chronic H. pylori infection is associated with increased risk for numerous disease outcomes including gastritis, dysplasia, neoplasia, B-cell lymphoma of mucosal-associated lymphoid tissue (MALT lymphoma), and invasive adenocarcinoma. The complex interactions that occur between pathogen and host are dynamic and exquisitely regulated, and the relationship between H. pylori and its human host are no exception. To successfully colonize, and subsequently persist, within the human stomach H. pylori must temporally regulate numerous genes to ensure localization to the gastric lumen and coordinated expression of virulence factors …

Flavodoxin-Like Proteins Protect Candida Albicans From Oxidative Stress And Promote Virulence, Lifang Li, Shamoon Naseem, Sahil Sharma, James B. Konopka

Department of Molecular Genetics and Microbiology Faculty Publications

The fungal pathogen Candida albicans causes lethal systemic infections in humans. To better define how pathogens resist oxidative attack by the immune system, we examined a family of four Flavodoxin-Like Proteins (FLPs) in C. albicans. In agreement with previous studies showing that FLPs in bacteria and plants act as NAD(P)H quinone oxidoreductases, a C.albicans quadruple mutant lacking all four FLPs (pst1Δ, pst2Δ, pst3Δ, ycp4Δ) was more sensitive to benzoquinone. Interestingly, the quadruple mutant was also more sensitive to a variety of oxidants. Quinone reductase activity confers important antioxidant effects because resistance …

Identification Of The Regulators Binding To The Upstream Region Of Glxr Of Corynebacterium Glutamicum, Bindu Subhadra, Durga Ray, Jong Yun Han, Kwang-Hee Bae, Jung-Kee Lee

Faculty Publications - Biological Sciences

GlxR is considered as a global transcriptional regulator controlling a large number of genes having broad physiological aspects in Corynebacterium glutamicum. However, the expression profile revealing the transcriptional control of glxR has not yet been studied in detail. DNA affinity chromatography experiments revealed the binding of transcriptional regulators SucR, RamB, GlxR, and a GntR-type protein (hereafter denoted as GntR3) to the upstream region of glxR. The binding of different regulators to the glxR promoter was confirmed by EMSA experiments. The expression of glxR was analyzed in detail under various carbon sources in the wild-type and different mutant strains. The sucR …

Meningeal Infiltration Of The Spinal Cord By Non-Classically Activated B Cells Is Associated With Chronic Disease Course In A Spontaneous B Cell-Dependent Model Of Cns Autoimmune Disease, Amy K. Dang, Yodit Tesfagiorgis, Rajiv W. Jain, Heather C. Craig, Steven M. Kerfoot

Microbiology & Immunology Publications

We characterized B cell infiltration of the spinal cord in a B cell-dependent spontaneous model of central nervous system (CNS) autoimmunity that develops in a proportion of mice with mutant T and B cell receptors specific for myelin oligodendrocyte glycoprotein. We found that, while males are more likely to develop disease, females are more likely to have a chronic rather than monophasic disease course. B cell infiltration of the spinal cord was investigated by histology and FACs. CD4⁺ T cell infiltration was pervasive throughout the white and in some cases gray matter. B cells were almost exclusively restricted to …

Local Bacteria Affect The Efficacy Of Chemotherapeutic Drugs, Panos Lehouritis, Joanne Cummins, Michael Stanton, Carola T Murphy, Florence O Mccarthy, Gregor Reid, Camilla Urbaniak, William L Byrne, Mark Tangney

Microbiology & Immunology Publications

In this study, the potential effects of bacteria on the efficacy of frequently used chemotherapies was examined. Bacteria and cancer cell lines were examined in vitro and in vivo for changes in the efficacy of cancer cell killing mediated by chemotherapeutic agents. Of 30 drugs examined in vitro, the efficacy of 10 was found to be significantly inhibited by certain bacteria, while the same bacteria improved the efficacy of six others. HPLC and mass spectrometry analyses of sample drugs (gemcitabine, fludarabine, cladribine, CB1954) demonstrated modification of drug chemical structure. The chemoresistance or increased cytotoxicity observed in vitro with sample drugs …

A Multi-Platform Metabolomics Approach Identifies Highly Specific Biomarkers Of Bacterial Diversity In The Vagina Of Pregnant And Non-Pregnant Women, Amy Mcmillan, Stephen Rulisa, Mark Sumarah, Jean M Macklaim, Justin Renaud, Jordan E Bisanz, Gregory B Gloor, Gregor Reid

Microbiology & Immunology Publications

Bacterial vaginosis (BV) increases transmission of HIV, enhances the risk of preterm labour, and is associated with malodour. Clinical diagnosis often relies on microscopy, which may not reflect the microbiota composition accurately. We use an untargeted metabolomics approach, whereby we normalize the weight of samples prior to analysis, to obtained precise measurements of metabolites in vaginal fluid. We identify biomarkers for BV with high sensitivity and specificity (AUC = 0.99) in a cohort of 131 pregnant and non-pregnant Rwandan women, and demonstrate that the vaginal metabolome is strongly associated with bacterial diversity. Metabolites associated with high diversity and clinical BV …

Demographics And Transfer Of Escherichia Coli Within Bos Taurus Populations, Joshua Ryan Dillard

Master's Theses

In the United States, symptoms caused by pathogenic strains of Escherichia coli are on the rise. A major source of these pathogenic strains is the E. coli in the digestive tract of cattle. The purpose of this project was to determine if E. coli are transferred between individuals of the same species and if interspecies transmission is possible. Proximity of cattle was also studied as a contributing factor to the transfer of E. coli. To accomplish this goal, E. coli isolates from cattle and cohabitating ground squirrels were compared through a new method of bacterial strain typing called pyroprinting. …

Lymphangioma Circumscriptum: Clinicopathological Spectrum Of 29 Cases, Saira Fatima, Nasir Uddin, Romana Idrees, Khurram Minhas, Zubair Ahmad, Rashida Ahmad, Naila Kayani, Muhammad Arif

Department of Pathology and Laboratory Medicine

Objective:
To describe the clinicopathological spectrum of Lymphangioma Circumscriptum (LC).
Study Design:
Observational case series.
Place and Duration of Study:
Department of Pathology and Microbiology, AKUH, Karachi, from 2002 to 2012.
Methodology:
All reported cases of LC were retrieved from medical record. Clinical and pathological features were noted. Frequency percentages were determined.
Results:
There were 29 cases of LC predominantly males (62%). The mean age was 27.17 ±15.5 years. The commonest sites was anal/perianal region (24%) followed by extremities (17%) and tongue, (14%). Vulval LC was seen in 3 patients. Two cases were described on scrotum. The lesions were most …

Drosophila Eye Model To Study Neuroprotective Role Of Creb Binding Protein (Cbp) In Alzheimer’S Disease, Timothy Cutler, Ankita Sarkar, Michael Moran, Andrew Steffensmeier, Oorvashi Roy Puli, Greg Mancini, Meghana Tare

Biology Faculty Publications

Background: The progressive neurodegenerative disorder Alzheimer’s disease (AD) manifests as loss of cognitive functions, and finally leads to death of the affected individual. AD may result from accumulation of amyloid plaques. These amyloid plaques comprising of amyloid-beta 42 (Aβ42) polypeptides results from the improper cleavage of amyloid precursor protein (APP) in the brain. The Aβ42 plaques have been shown to disrupt the normal cellular processes and thereby trigger abnormal signaling which results in the death of neurons. However, the molecular-genetic mechanism(s) responsible for Aβ42 mediated neurodegeneration is yet to be fully understood.

Methodology/Principal Findings: We have utilized Gal4/UAS system to …

Pathogen-Specific Burdens Of Community Diarrhoea In Developing Countries: A Multisite Birth Cohort Study (Mal-Ed), Sadia Shakoor, Shahida Qureshi, Furqan Kabir, Anita K. M. Zaidi, Zulfiqar Ahmed Bhutta, Imran Ahmed, Didar Alam, Syed Asad Ali, Muneera Rasheed, Sajid Bashir Soofi, Ali Turab, Aisha Khizar Yousafzai

Department of Pathology and Laboratory Medicine

Background: Most studies of the causes of diarrhoea in low-income and middle-income countries have looked at severe disease in people presenting for care, and there are few estimates of pathogen-specific diarrhoea burdens in the community.
Methods: We undertook a birth cohort study with not only intensive community surveillance for diarrhoea but also routine collection of non-diarrhoeal stools from eight sites in South America, Africa, and Asia. We enrolled children within 17 days of birth, and diarrhoeal episodes (defined as maternal report of three or more loose stools in 24 h, or one loose stool with visible blood) were identified through …

The Cababc Operon Essential For Biofilm And Rugose Colony Development In Vibrio Vulnificus, Jin Hwan Park, Youmi Jo, Song Yee Jang, Haenaem Kwon, Yasuhiko Irie, Matthew R. Parsek, Myung Hee Kim, Sang Ho Choi

Biology Faculty Publications

A transcriptome analysis identified Vibrio vulnificus cabABC genes which were preferentially expressed in biofilms. The cabABC genes were transcribed as a single operon. The cabA gene was induced by elevated 3′,5′-cyclic diguanylic acid (c-di-GMP) and encoded a calcium-binding protein CabA. Comparison of the biofilms produced by the cabA mutant and its parent strain JN111 in microtiter plates using crystal-violet staining demonstrated that CabA contributed to biofilm formation in a calcium-dependent manner under elevated c-di-GMP conditions. Genetic and biochemical analyses revealed that CabA was secreted to the cell exterior through functional CabB and CabC, distributed throughout the biofilm matrix, and produced …

Absence Of Soda Increases The Levels Of Oxidation Of Key Metabolic Determinants Of Borrelia Burgdorferi, Maria D. Esteve-Gassent, Trever C. Smith Ii, Christina M. Small, Derek P. Thomas, J Seshu

Peer Reviewed Articles

Borrelia burgdorferi, the causative agent of Lyme disease, alters its gene expression in response to environmental signals unique to its tick vector or vertebrate hosts. B. burgdorferi carries one superoxide dismutase gene (sodA) capable of controlling intracellular superoxide levels. Previously, sodA was shown to be essential for infection of B. burgdorferi in the C3H/HeN model of Lyme disease. We employed two-dimensional electrophoresis (2-DE) and immunoblot analysis with antibodies specific to carbonylated proteins to identify targets that were differentially oxidized in the soluble fractions of the sodA mutant compared to its isogenic parental control strain following …

An Exploration Of The Phylogenetic Placement Of Recently Discovered Ultrasmall Archaeal Lineages, Jeffrey M. O'Brien

Honors Scholar Theses

In recent years, several new clades within the domain Achaea have been discovered. This is due in part to microbiological sampling of novel environments, and the increasing ability to detect and sequence uncultivable organisms through metagenomic analysis. These organisms share certain features, such as small cell size and streamlined genomes. Reduction in genome size can present difficulties to phylogenetic reconstruction programs. Since there is less genetic data to work with, these organisms often have missing genes in concatenated multiple sequence alignments. Evolutionary Biologists have not reached a consensus on the placement of these lineages in the archaeal evolutionary tree. There …

Role Of The Dna Sensor Sting In Protection From Lethal Infection Following Corneal And Intracerebral Challenge With Herpes Simplex Virus 1, Zachary M. Parker, Aisling A. Murphy, David. A. Leib

Dartmouth Scholarship

STING is a protein in the cytosolic DNA and cyclic dinucleotide sensor pathway that is critical for the initiation of innate responses to infection by various pathogens. Consistent with this, herpes simplex virus 1 (HSV-1) causes invariable and rapid lethality in STING-deficient (STING(-/-)) mice following intravenous (i.v.) infection. In this study, using real-time bioluminescence imaging and virological assays, as expected, we demonstrated that STING(-/-) mice support greater replication and spread in ocular tissues and the nervous system. In contrast, they did not succumb to challenge via the corneal route even with high titers of a virus that was routinely lethal …

Draft Genome Sequence Of A Community-Associated Methicillin- Resistant Panton-Valentine Leukocidin-Positive Staphylococcus Aureus Sequence Type 30 Isolate From A Pediatric Patient With A Lung Infection In Brazil, Craig M. Stephens, Paul Jang-Yeon Cho, Veronica Afonso De Araujo, Ivete Martins Gomes, Selma Maria De Azevedo Sias, Claudete A. Araújo Cardoso, Lee W. Riley, Fábio Aguiar-Alves

Biology

The sequence of methicillin-resistant Staphylococcus aureus strain B6 (sequence type 30 [ST30], spa type t433, staphylococcal chromosomal cassette mec element [SCCmec] type IVc, Panton-Valentine leukocidin [PVL] positive), isolated from a pediatric patient with a lung infection in Niterói, Rio de Janeiro, Brazil, is described here. The draft genome sequence includes a 2.8-Mb chromosome, accompanied by a 20-kb plasmid containing blaZ and two small cryptic plasmids.

Role Of The C-Terminus Of The Catalytic Subunit Of Translesion Synthesis Polymerase Ζ (Zeta) In Uv-Induced Mutagensis, Hollie M. Siebler

Theses & Dissertations

Cellular DNA is under constant attack by endogenous and exogenous DNA damaging agents that threaten genome integrity. Unrepaired DNA lesions often stall replicative DNA polymerases and are bypassed by translesion synthesis (TLS) to prevent replication fork collapse. TLS mechanisms are lesion- and species-specific, with prominent roles of specialized DNA polymerases with relaxed active sites. After incorporation of nucleotide(s) across from the lesion, the distorted primer termini are typically extended by DNA polymerase ζ (Pol ζ). As a result, Pol ζ is responsible for most DNA damage-induced mutations. Mechanisms of sequential polymerase switches and regulation of Pol ζ access to DNA …

Characterization Of The Replication Of Coxsackievirus B3 With A Mutationally Disrupted Cre(2c) And The Use Of Creatinine-Hydrochloride As An Antibacterial Agent, Shane E. Smithee

Theses & Dissertations

Following natural or experimental infection, and in cell culture, coxsackie B virus (CVB) RNA can persist for weeks in the absence of CPE yet with detectable viral RNA. Earlier studies in our laboratory demonstrated that this persistence produced viral RNA with up to 49 nucleotide deletions at the 5’ genomic terminus, partially degrading the cloverleaf (or domain I), an RNA structure that is required for efficient viral replication. A cis-acting replication element (CRE) in the 2C protein coding region [CRE(2C)] templates the addition of two uridine residues to the virus-encoded RNA replication primer, VPg, prior to genomic replication. Because …

Suitability Of Great South Bay, New York To Blooms Of Pfiesteria Piscicida And P. Shumwayae Prior To Superstorm Sandy, October 29, 2012, Pawel Tomasz Zablocki

Theses and Dissertations

Pfiesteria piscicida and P. shumwayae are toxic dinoflagellates implicated in massive fish kills in North Carolina and Maryland during 1990s. A set of physical, chemica l, and biological factors influence population dynamics of these organisms. This study employs i nformation gathered from relevant literature on temperature, salinity, dissolved oxygen, pH, turbulent mixing, and dissolved nutrients, bacteria, algae, microzooplankton, mesozooplankton, bivalve m ollusks, finfish, and other toxic dinoflagellates, which influence Pfiesteria population dynamics. The research focused on whether conditions in the Great South Bay, Long Island, New York were suitable to blooms of Pfiesteria species prior to the passage of superstorm …

You Don’T Have To Go Home But You Carrot Stay Here: Root-Knot Nematode Biological Control In Carrots, Casey R. Martin, Sahar Abdelrazek, Lori A. Hoagland

The Summer Undergraduate Research Fellowship (SURF) Symposium

Root-knot nematodes cause tens of billions of dollars in damages annually in agricultural production. The enormous economic losses brought about by nematodes, combined with the downsides to current methods for handling them, have led to an increased focus in understanding natural plant defense mechanisms and finding alternative methods to lessen the damage done by root-knot nematodes. Endophyte biocontrol agents such as Trichoderma harzianum have shown promise in reducing nematode damage. Recent studies have demonstrated that soil management practices and plant genotype can influence endophyte community structure, but it is unclear whether such differences influence susceptibility to nematode damage. This study …

A Novel Synthetic Yeast For Enzymatic Biodigester Pretreatment, Tianyu Tan, Mark S. Aronson, Arren Liu, Jill H. Osterhus, Melissa Robins, Suraj Mohan, Erich Leazer, Bowman Clark, Alexa Petrucciani, Katherine Lowery, James Welch, Casey Martin, Helena Lysandrou, Michael E. Scharf, Jenna Rickus

The Summer Undergraduate Research Fellowship (SURF) Symposium

Lignin, a complex organic polymer, is a major roadblock to the efficiency of biofuel conversion as it both physically blocks carbohydrate substrates and poisons biomass degrading enzymes, even if broken down to monomer units. A pretreatment process is often applied to separate the lignin from biomass prior to biofuel conversion. However, contemporary methods of pretreatment require large amounts of energy, which may be economically uncompelling or unfeasible. Taking inspiration from several genes that have been isolated from termites and fungi which translate to enzymes that degrade lignin, we want to establish a novel “enzymatic pretreatment” system where microbes secrete these …

Weak Interactions Between Salmonella Enterica Flhb And Other Flagellar Export Apparatus Proteins Govern Type Iii Secretion Dynamics, Jonathan L. Mcmurry, Tohru Minamino, Yukio Furukawa, Joshua W. Francis

Faculty Articles

The bacterial flagellum contains its own type III secretion apparatus that coordinates protein export with assembly at the distal end. While many interactions among export apparatus proteins have been reported, few have been examined with respect to the differential affinities and dynamic relationships that must govern the mechanism of export. FlhB, an integral membrane protein, plays critical roles in both export and the substrate specificity switching that occurs upon hook completion. Reported herein is the quantitative characterization of interactions between the cytoplasmic domain of FlhB (FlhBC) and other export apparatus proteins including FliK, FlhAC and FliI. FliK and FlhAC bound …

Hydrologic Modeling Of The Effects Of Stormwater Runoff In Plaster Creek Watershed, Ryan Degroot, Julie Wildschut, Robert Hoeksema

Student Papers and Reports

No abstract provided.

Installation Of Rain Gardens In The Alger Heights Community, Wesley Dykstra, Dena De Kryger, Mike Ryskamp, David P. Warners

Student Papers and Reports

No abstract provided.

The Effect Of Environmental Selection Pressure On The Rate Of Recombination To An Advantageous Receptor Mutation In Bovine Coronavirus, Gavin Schroter, Sally Hall, Mona Hwang, Monica Borucki

STAR Program Research Presentations

Bovine Coronavirus (BCoV) is an important analogue in understanding the effectiveness of zoonotic, single-stranded, positive sense RNA viruses. Many of the most recent viral outbreaks have been attributed to RNA viruses that have one, or more, animal reservoirs [1]. BCoV is such a great candidate for studying these types of viruses because they are from the family Coronaviridae, which also contains the viruses that cause severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS). The goal of this study was to observe changes in genetic makeup of the virus’ outer membrane Spike protein via recombination between two …

How Many Particles Are Present In The Air? Bioaerosol Detection Using An Air Particle Counter, Angie Pamela Rivera, Parag Vaishampayan

STAR Program Research Presentations

Relative cleanliness in terms of particle abundance in spacecraft assembly facilities is determined by particle counts carried out in clean rooms during resting conditions. Particle counters assess total particles and particle size distribution, but do not distinguish inert particles from biological particles, which may include bacterial spores that are resistant to standard cleanroom sterilization procedures. Current cleanroom certifications do not fully assess the effects of human presence on spacecraft contamination since humans are known symbionts to enumerate microorganisms and assessments are performed at rest when there is no human presence. In this study, contamination risks and bioburden in spacecraft assembly …

Collecting Diverse Microorganisms From Rover Spacecraft, Jennifer I. Jacobs, Arianna Jefferson, Heidi Aronson, James Tan, Wayne Schubert, Parag Vaishampayan

STAR Program Research Presentations

. The Planetary Protection discipline at NASA’s Jet Propulsion Laboratory develops and implements procedures to prevent both forward and backward contamination between the Earth and solar system bodies. However, there will always be some microorganisms that will be resistant to the strictest of sterilization methods. In order understand the microorganisms found on spacecraft during assembly, and to rapidly identify them, a mass spectrometry approach was developed. As an experimental approach, a custom database was created for a subset of microorganisms in the Planetary Protection Archive. In order to make the database as accurate and efficient as possible, several different procedures …

Relationships Between Growth Rate And Gene Expression In Ruegeria Pomeroyi Dss-3, A Model Marine Alphaproteobacterium, Nattasha Vinas

All Theses

Microbes are important contributors to ecosystem processes such as biogeochemical cycling. Their activities vary, depending on environmental parameters such as carbon type and concentration, temperature, and salinity. Current estimates of in situ microbial growth is limited to gross estimates or rely on incubation based methods that disturb the natural state of the community. The goal of this master’s thesis is to develop molecular methods to directly assess microbial growth rates in the environment at the level of a taxonomic group. Here we grew Ruegeria pomeroyi DSS-3 under different temperatures (15 °C or 30 °C) and different carbon sources (yeast extract/tryptone, …

Prevalence Of A Chytrid Pathogen (Batrachochytrium Dendrobatidis) In Eastern Hellbender Salamanders In New York And Pennsylvania, Linxuan Wu

Biology Theses

Amphibian populations are currently declining globally. There are many possible causes for these declines, among which an emerging infectious disease, chytridiomycosis, has been implicated. Chytridiomycosis in the U.S.A. is mainly caused by the Batrachochytrium dendrobatidis. In this study, I used qPCR assays to detect the existence of this pathogen in the Eastern Hellbender (Cryptobranchus alleganiensis alleganiensis) populations in the Allegheny and Susquehanna River drainages of New York and Pennsylvania. Chytrid is most often tested by using skin swabs, but in this study, tail clips, dorsal skin, blood and eggs were tested as well. Batrachochytrium dendrobatidis was detected …

Autologous Hematopoietic Stem Cell Transplantation-10 Years Of Data From A Developing Country, Natasha Ali, Salman Naseem Adil, Mohammad Usman Shaikh

Department of Pathology and Laboratory Medicine

Intensive chemotherapy followed by autologous stem cell transplantation is the treatment of choice for patients with hematological malignancies. The objective of the present study was to evaluate the outcomes of patients with mainly lymphoma and multiple myeloma after autologous stem cell transplant. The pretransplant workup consisted of the complete blood count, an evaluation of the liver, kidney, lung, and infectious profile, chest radiographs, and a dental review. For lymphoma, all patients who achieved at least a 25% reduction in the disease after salvage therapy were included in the study. Mobilization was done with cyclophosphamide, followed by granulocyte colony-stimulating factor, 300 …