Microbiology Commons^™

How Yersinia Pseudotuberculosis Biofilm Formation Is Regulated By Global Regulator Csra, Jeffrey Schachterle, David Erickson

Journal of Undergraduate Research

The bacteria Yersinia pestis is the causative agent of bubonic plague, and its ability to form biofilm in fleas is essential for plague transmission by fleas [1]. Y. pestis recently evolved from Y. pseudotuberculosis (Y. pstb), and the two have nearly identical genomes. Y. pestis forms a biofilm in fleas that is capable of blocking the flea’s feeding. These biofilms are made up of a community of bacteria adhering to a polysaccharide matrix that is made by the hmsHFRS gene products. Y. pstb is capable of infecting fleas, but will not block the flea’s feeding [1]. Since the …

A Method Of Introducing Site Specific Mutations Into The Phor Gene Of The E. Coli Chromosome, Cameron Woodward, William Mccleary

Journal of Undergraduate Research

Phosphate intake by Escherichia coli serves as a good model system to study phosphate intake by other bacteria. The pho phosphate uptake system used by E. coli is well conserved in pathogens like Vibrio cholerae (1). To better understand this important mode of phosphate uptake a study was performed to examine the interactions between the phoR and phoU proteins of this system. PhoU interacts with the pstSCAB complex, which brings phosphate into the cell. After communicating with pstSCAB the phoU protein interacts with phoR to tell it if phosphate is present in the environment or not. PhoR has been shown …

Detection Of Hcmv Viral Il-10 (Vil-10) In Healthy Blood Donors, Vivian P. Young

Master's Theses

Human cytomegalovirus (HCMV) is widespread in the general population and can establish lifelong latency with expression of a limited subset of viral genes. The UL111A gene is expressed during both lytic and latent infection, and at least two protein isoforms are produced. During lytic infection, the full length transcript yields cmvIL-10, a potent immunosuppressive viral ortholog of human IL-10 (hIL-10). Alternative splicing of the UL111A transcript yields a truncated protein, LAcmvIL-10, which is expressed during both lytic and latent infection but with a limited range of immunosuppressive functions. The two viral cytokines, collectively termed viral IL-10 (vIL-10), are identical in …

Functional Analysis Of The Molluscum Contagiosum Virus Mc160 Death Effector Domain-Containing Protein Rxdl Motif, Sarah Weber

Seton Hall University Dissertations and Theses (ETDs)

The Molluscum contagiosum virus (MCV) is a member of the Poxviridae family that causes benign skin lesions. MCV lesions persist on average for 8-12 months in otherwise healthy individuals. MCV lesions are characterized by reduced inflammation. The persistence and reduction of inflammation at the site of MCV lesions have been attributed to MCV immune evasion genes. MCV encodes two death effector domain (DED) containing proteins, MC159 and MC160. DEDs are found in cellular proteins such as FADD and procaspase-8. These cellular proteins are involved in several innate immune responses such as apoptosis and activation of interferon (IFN). Presumably, MC159 and …

Characterizing Dna2 In Model Plant Arabidopsis, Connor Woodward, Brent Nielsen

Journal of Undergraduate Research

Dna2 is a protein that is known to be essential for DNA replication in human and yeast mitochondria. In these organisms it acts as both a helicase and an endonuclease. In the model plant Arabidopsis thaliana an ortholog of Dna2 exists but has never been studied. Two questions were answered in this study. The first question is “What would happen to A. thaliana plants that lacked Dna2?”. The second is “Where is Dna2 localized in plant cells?”

The C-Terminal Linker Of Ftsz Acts As An Intrinsically Disordered Peptide During Cell Division In Bacillus Subtilis, Steven Grigsby

Undergraduate Theses—Unrestricted

The bacterial tubulin homologue FtsZ polymerizes in vitro in a GTP-dependent manner to form long, single stranded filaments. In cells, these filaments assemble at the nascent division site, interacting laterally to form the contractile Z ring. The Z ring serves as a scaffold for the rest of the division machinery and constricts at the leading edge of the invaginating septum during cytokinesis. The FtsZ polypeptide consists of three primary domains: the N-terminal globular core consisting of 315 residues that contains the GTP binding site, a variable and flexible C-terminal linker (CTL) consisting of 50 residues, and a conserved region at …

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.

Addressing The Black Box Phenomenon Of Genome Sequencing And Assembly, Brandon Carter

Senior Honors Projects, 2010-2019

Genomics, a study of all genetic material in an organism, is a new discipline having a great impact on medicine, agriculture, and environmental phenomena. Most undergraduate faculty members were not formally trained in genomics and must retool themselves in order to stay current with these evolving technologies. Advances in sequencing technology have resulted in an explosion of “big data” that can only be managed and analyzed using digital methods. Multiple complex computer programs are required to teach students the concepts using hands-on methods. These programs are challenging to use, especially since the same faculty members lacking genomics training were not …

Transduction As The Method Of Horizontal Gene Transfer Of The Staphylococcal Chromosomal Cassette Mec (Sccmec), Amber B. Sauder

Senior Honors Projects, 2010-2019

Methicillin-resistant Staphylococcus aureus (MRSA) gains resistance to β-lactam antibiotics through a mutated penicillin binding protein (PBP2a) encoded on the SCCmec element. In combination with the recombinase encoded by ccr, these two genes are used as markers of the mobile genetic element (SCCmec). Due to recent increases in community acquired MRSA infections, the mechanisms of antibiotic resistance gene transfer have gained attention. Transduction, a method of horizontal gene transfer mediated by bacteriophage, is believed to be responsible for the movement of the SCCmec element. Recent studies have shown the transduction of the SCCmec element in clinical isolates; however, this study is …

Tricistronic Lentivirus Vector Construction Using Scar-Less Dna Assembly Methods And Web-Based Software J5 To Help Study Grk4, Christophe Langouet-Astrie

Senior Honors Projects, 2010-2019

About one third of the world’s population is affected by hypertension, or high blood pressure, which increases an individual’s risk for cardiovascular disease. A major contributor to hypertension is dietary sodium intake. To assess an individual’s risk for hypertension, patients are put on a low sodium diet. However, research has shown that low salt intake can also have different and potentially harmful effects. Because of this, a genetic screen for salt sensitivity is needed to asses an individual’s salt sensitivity classification before testing and these results matched to a recommended dietary change. The kidney regulates the body’s fluid volume, so …

Comparative Analysis Of Anti-Bd Bacteria From Six Malagasy Frog Species Of Ranomafana National Park, Kelsey Savage

Senior Honors Projects, 2010-2019

As Malagasy amphibians are facing an impending extinction crisis from the lethal skin fungus Batrachochytrium dendrobatidis (Bd), it has become imperative to proactively mitigate the threat. Bd sporangia develop in the skin of infected amphibians and cause the skin to thicken, leading to ionic imbalance and eventual heart failure. It has been shown that certain bacterial species are able to inhibit Bd growth on amphibians by producing antifungal metabolites. Community-based probiotics are one approach used to combat chytridomycosis by inoculating an environment with Bd-inhibitory bacteria so that many amphibian species are treated at once. With this method, it is important …

Cave Cyanobacteria Showing Antibacterial Activity, Vasiliki Lamprinou, Kyriaki Tryfinopoulou, Emmanuel N. Velonakis, Alkiviadis Vatopoulos, Smaragdi Antonopoulou, Elizabeth Fragopoulou, Adriani Pantazidou, Athena Economou-Amilli

International Journal of Speleology

Cave Cyanobacteria - thriving in an ‘extreme’ environment with interesting species biodiversity - are supposed to be a potential source of bioactive compounds. Lipid extracts from pure cultures of two recently established Cyanobacteria from Greek caves, Toxopsis calypsus and Phormidium melanochroun, were used for antibacterial screening against human pathogenic bacteria (reference and clinical isolates). Antimicrobial Susceptibility testing for both taxa was carried out using the disc-diffusion (Kirby Bauer) method, while preliminary data applying the standard broth microdilution method for the determination of the Minimal Inhibitory Concentration (MIC) are given only for T. calypsus. Antibacterial activity was demonstrated against the …

Comparison Of The Antibacterial, Colloidal, And Hemolytic Properties Of Novel Triple-Headed, Triscationic Amphiphiles, Tara Gallagher

Masters Theses, 2010-2019

Antibiotic resistant bacteria were first reported in the 1940s, several years after the clinical introduction of penicillin. Since then, antibiotic resistance has contributed to increasing bacterial infections, mortality rates, and treatment costs. One promising alternative to traditional antibiotics is the development and use of amphiphiles, compounds with at least one hydrophilic head group and one hydrophobic tail. Three novel series of triple-headed amphiphiles with variations in the third head group composition, tail length and number of tails (one or two) were synthesized. Isothermal titration calorimetry was used to determine the critical micelle concentration – the concentration at which amphiphiles aggregate …

Effect Of Cmvil-10 On Exosome Production By Human Breast Cancer Cells, Susanna N. Basappa

Undergraduate Honors Theses

Human cytomegalovirus (HCMV) is a ubiquitous virus that infects 70-90% of the general population, primarily the immunocompromised, but has been implicated in several forms of cancer, including breast cancer. Breast cancer is the second leading cause of cancer related deaths in women in North America, usually from metastasis. Exosomes are 30-100nm vesicles produced by most cells which carry protein and RNA to cells in their microenvironment. The aim of this study is to investigate the impact of HCMV-infection of a secreted viral cytokine, cmvIL-10, on exosome production by highly metastatic breast cancer cells.

MDA-MB-231 cells were cultured in vitro, …

Characterization And Fluorescence Of Yellow Biofilms In Karst Caves, Southwest Slovenia, Janez Mulec, Andreea Oarga-Mulec, Rok Tomazin, Tadeja Matos

International Journal of Speleology

Biofilms of different colours that colonize surfaces within karst caves represent a source of nutrients. They occur commonly and abundantly at sites with sediments, and close to seepages or underground rivers. Golden-yellow subaerial biofilms are particularly well observed because of their contrast with their surroundings, the characteristics of the pigment and recently, even more, due to the characteristics of light-emitting diode (LED) illumination. Yellow microbial biofilms were sampled from three caves in southwestern Slovenia, Dimnice, Križna jama and Sveta jama. The highest concentration of cultivable microbes (2.33×10⁸ CFU/g) and the biggest number of identified bacteria (66.0%) were retrieved from …

Tonb Not Directly Related To Efflux Of Antibiotics In E. Coli, Amber Gombash

Honors Projects

Studies in Pseudomonas aeruginosa have suggested that the TonB energy transduction system directly contributes to efflux-mediated antibiotic resistance, ostensibly by energizing one or more efflux systems. We have found ∆tonB strains of Escherichia coli to similarly be more sensitive to certain antibiotics relative to wild-type strains. To test the hypothesis that this enhanced sensitivity involved the energization of efflux systems, sensitivity patterns for a variety of antibiotics were evaluated using a set of strains differentially lacking genes encoding the Acr efflux system, the universal outer membrane efflux portal TolC, and TonB. No correlation was evident between the resistance phenotypes of …

A Synthetic Lethal Screen Identifies A Role For Lin-44/Wnt In C.Elegans Embryogenesis, Samanth N. Hartin, Martin L. Hudson, Curtis Yingling, Brian D. Ackley

Faculty Articles

Background The C. elegans proteins PTP-3/LAR-RPTP and SDN-1/Syndecan are conserved cell adhesion molecules. Loss-of-function (LOF) mutations in either ptp-3 or sdn-1 result in low penetrance embryonic developmental defects. Work from other systems has shown that syndecans can function as ligands for LAR receptors in vivo. We used double mutant analysis to test whether ptp-3 and sdn-1 function in a linear genetic pathway during C. elegans embryogenesis. Results We found animals with LOF in both sdn-1 and ptp-3 exhibited a highly penetrant synthetic lethality (SynLet), with only a small percentage of animals surviving to adulthood. Analysis of the survivors demonstrated that …

Section Abstracts: Biology With Microbiology And Molecular Biology

Virginia Journal of Science

Abstracts of the Biology with Microbiology and Molecular Biology Section for the 93rd Annual Meeting of the Virginia Academy of Science, May 21-23, 2015, James Madison University, Richmond, Virginia

Epiphytic Diatom Community Structure In A Karst Riverine System, Gregory John Barren

Masters Theses & Specialist Projects

The goal of this study was to assess the epiphytic diatom community structure of two host species along a karst gradient in the upper Green River, Kentucky to a gain a better understanding of the role of diatoms in the food web. The host species studied were Podostemum ceratophyllum and Cladophora. Percent cover of P. ceratophyllum and Cladophora were quantified in the four study reaches. The host species were sampled near-shore and mid-channel in each reach in September and October of 2013. After diatoms were extracted from the host and enumerated the density and diversity were quantified. Twelve genera were …

Evolution Of Sperm Activation In Nematodes, Qing Wei

Graduate School of Biomedical Sciences Theses and Dissertations

Three hermaphroditic species in the nematode genus Caenorhabditis - C. elegans, C. briggsae and C. tropicalis evolved independently from a male/female ancestor. Thus, the hermaphroditic reproductive system provides an ideal subject for studying the origin of new complex traits. Previous studies implied that this transition required two steps: a mutation that caused XY animals to make sperm, and a mutation that allowed XX spermatids to activate and fertilize oocytes. In this dissertation, I show how sperm activation is regulated in different hermaphroditic species.

First, I used TALENs to create genetic tools for C. briggsae and C. tropicalis. These tools were …