Microbiology Commons^™

Characterization And Regulation Of The Icsp And Ospz Locus In Shigella Flexneri, Krystle Lashell Pew

UNLV Theses, Dissertations, Professional Papers, and Capstones

Shigella flexneri is a gram negative, rod shaped bacterium that is the causative agent of bacillary dysentery, which is characterized by fever, abdominal pain, and bloody diarrhea. Genes essential to the pathogenicity of S. flexneri are encoded by a virulence plasmid. Shigella has evolved a complex regulatory system to regulate transcription of virulence genes. This involves two regulators, VirF and VirB, which allow the bacterium to respond to environmental stimuli and maximally exploit host niches. An additional factor impacting virulence gene regulation is H-NS, a histone nucleoid structuring protein that globally represses transcription. This work addresses the transcriptional regulation of …

Novel Model For Multispecies Biofilms That Uses Rigid Gas-Permeable Lenses, Rebecca Peyyala, Sreenatha S. Kirakodu, Jeffrey L. Ebersole, Karen F. Novak

Center for Oral Health Research Faculty Publications

Oral biofilms comprise complex multispecies consortia aided by specific inter- and intraspecies interactions occurring among commensals and pathogenic bacterial species. Oral biofilms are primary initiating factors of periodontal disease, although complex multifactorial biological influences, including host cell responses, contribute to the individual outcome of the disease. To provide a system to study initial stages of interaction between oral biofilms and the host cells that contribute to the disease process, we developed a novel in vitro model system to grow biofilms on rigid gas-permeable contact lenses (RGPLs), which enable oxygen to permeate through the lens material. Bacterial species belonging to early- …

Archaeoparasitology Of Chaco Canyon, Rachel Paseka

Department of Environmental Studies: Undergraduate Student Theses

Ancient cultures of the Colorado Plateau have been a focus of archaeoparasitology since its inception, and a vast parasitological history is recorded in coprolites preserved in this arid region. The inhabitants of Chaco Canyon dominated Ancestral Puebloan culture between 1050 and 1120 AD and were responsible for the construction of great towns, road systems, and early agriculture. Analysis of the parasites preserved in fecal remains contributes to an increased knowledge of ancient Chacoan health and culture. Nineteen coprolites from four sites in Chaco Canyon were rehydrated and analyzed microscopically for parasite remains. Rhabditiform and filariform nematode larvae were found from …

Microbiological Safety Of Organic Fertilizers Used For Produce Production, Cortney Miller

All Theses

Over the last few decades there has been an increase in the use of organic fertilizers due to the rise in popularity of organic food production. However, if the fertilizers are not adequately sanitized there is the possibility of contamination of agricultural crops by foodborne pathogens from the spreading of organic fertilizers onto the crops. This is especially important for animal waste-based fertilizers since animals frequently carry foodborne pathogens. Furthermore, antibiotic use in food animal production may induce antimicrobial resistance in gut bacteria which can be spread to crops and the environment through fertilizer use. The objectives of this study …

Requirement Of Ssdelseed-Motif Of Escherichia Coli F1FO Atp Synthase In Antimicrobial Peptide Binding., Junior Kom Tayou

Electronic Theses and Dissertations

F₁F_O ATP synthase is a membrane bound enzyme capable of synthesizing and hydrolyzing ATP. Lately, α-helical cationic peptides such as melittin and melittin related peptide (MRP) were shown to inhibit E. coli ATP synthase. The proposed but unconfirmed site of inhibition is βDELSEED-motif formed by the residues 380-386, located at the interface of α/β subunit of ATP synthase. This project was a mutagenic analysis of βDELSEED-motif residues to understand the binding mechanism and mode of action of peptide inhibitors. The study addressed 2 main questions: Are the antibacterial/anticancer effects of these peptides related to their inhibitory action …

Using Polymerase Chain Reaction To Detect Nifh And Vnfdgk In A Novel Acidophilic Microbial Community, Samantha L. Flowers

Undergraduate Honors Theses

Acidophiles are widely known for their ability to exploit harsh environments, typically consisting of high temperatures, dissolved metal concentrations, and acidic conditions. Consequently, different acidophilic species are employed industrially in applications such as biomining and bioleaching. However, their full potential in bioremediation, and in industrial practices, has yet to be fully explored because many of these acidophiles are difficult to culture in laboratory conditions or have yet to be properly identified. This investigation focuses on a novel community sampled from the Richmond Mine site in Iron Mountain, California, consisting of a filamentous fungus and prokaryotes. This consortium can be cultured …

Design Of A Factorial Experiment With Randomization Restrictions To Assess Medical Device Performance On Vascular Tissue, Wiebke Diestelkamp, Carissa M. Krane, Margaret Pinnell

Biology Faculty Publications

Background: Energy-based surgical scalpels are designed to efficiently transect and seal blood vessels using thermal energy to promote protein denaturation and coagulation. Assessment and design improvement of ultrasonic scalpel performance relies on both in vivo and ex vivo testing. The objective of this work was to design and implement a robust, experimental test matrix with randomization restrictions and predictive statistical power, which allowed for identification of those experimental variables that may affect the quality of the seal obtained ex vivo.

Methods: The design of the experiment included three factors: temperature (two levels); the type of solution used to perfuse the …

Endo-Porter–Mediated Delivery Of Phosphorodiamidate Morpholino Oligos (Pmos) In Erythrocyte Suspension Cultures From Cope's Gray Treefrog Hyla Chrysoscelis, Venkateshwar Mutyam, Matthew V. Puccetti, James Frisbie, David L. Goldstein, Carissa M. Krane

Biology Faculty Publications

Cope's gray treefrog, Hyla chrysoscelis, is a freeze-tolerant anuran that accumulates cryoprotective glycerol during cold acclimation. H. chrysoscelis erythrocytes express the aquaglyceroporin HC-3, which facilitates transmembrane glycerol and water movement. Aquaglyceroporins have no pharmacological inhibitors, and no genetic knockout tools currently exist for H. chrysoscelis. A phosphorodiamidate morpholino oligo (PMO)–mediated expression knockdown approach was therefore pursued to provide a model for testing the role of HC-3. We describe a novel procedure optimized for specific, efficient knockdown of HC-3 expression in amphibian erythrocyte suspensions cultured at nonmammalian physiological temperatures using Endo-Porter. Our protocol includes three critical components: pre-incubation at 37°C, …

Knowledge And Beliefs Among Health Care Workers Regarding Hepatitis B Infection And Needle Stick Injuries At A Tertiary Care Hospital, Karachi, Faiza Habib, Durreshahwar K Khan, Shan-E Abbas, Faiza Bhatti, Afia Zafar

Department of Pathology and Laboratory Medicine

Hepatitis B virus (HBV) infection is a recognized occupational risk for health care workers (HCWs). This study aimed to assess the knowledge and beliefs of HCWs regarding HBV transmission and needle stick injuries (NSIs). A cross-sectional questionnaire based KAP study was conducted at Civil Hospital, Karachi, during the period of January to September 2006. HCWs were inquired about possible modes of HBV transmission and association with NSIs. Data were entered using EpiInfo 6.04d software. Statistical analysis was performed using SPSS 12.5 software. A total of 343 HCWs participated, and those answered at least 5 correct modes of HBV transmission were …

Investigation Of Bovine Herpesvirus 1 (Bhv-1) Encoded Infected Cell Protein 0 (Bicp0), Natasha N. Gaudreault

School of Biological Sciences: Dissertations, Theses, and Student Research

Bovine herpesvirus 1 (BHV-1) is a significant pathogen of cattle.  Following acute infection, BHV-1 establishes a latent infection that persists for the life of the infected host.  Stress induced factors cause the virus to reactivate from latency, resulting in virus transmission and transient immune suppression.  BHV-1 encoded bICP0 is expressed early and constitutively throughout productive infection.  bICP0 is critical for efficient viral replication, virulence, and reactivation in cattle because it stimulates viral transcription and interferes with innate immune responses.  bICP0 potentially interacts with a variety of proteins to activate viral gene expression and inhibit innate antiviral defenses.  bICP0 localizes to …

An Investigation Of The Composition, Microbial Digestion And Potential Applications Of An Industrial By-Product Of Seaweed Extraction, Juncal Nogales Esteban

Theses

Commercial preparation of seaweed extract from Ascophyllum nodosum, for use as fertilizer and soil improver, produces a residue which requires remediation. This residue is rich in nutrients and offers potential for other added-value products. The residue’s composition and microbial flora were studied, a microbial digestion system was developed, and extracts were screened for anti-hyaluronidase and anti-elastase activities.

The residue had a pH of 8.61±0.39, 16% (w/w) TS which comprised 40.6% minerals, 29.5% fibre, 20.9% lipid, 4.9% protein and 0.48% polyphenols. The microbial digestion included an initial 3-day anaerobic phase during which pH decreased from 9.12 to 7.89. At day 3, …

Identification, Cloning And Characterization Of Van Operon In Cyanobacterium Synechococcus Sp. Iu 625, Robert Newby Jr.

Seton Hall University Dissertations and Theses (ETDs)

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Role Of Vitamin-D3 And Retinoic Acid In A Human Thp-1 Macrophage Model Of Mycobacterium Tuberculosis Infection, Jaymie L. Estrella

Dissertations and Theses (Open Access)

Mycobacterium tuberculosis (Mtb) replicates within the human macrophages and we investigated the activating effects of retinoic acid (RA) and vitamin D3 (VD) on macrophages in relation to the viability of Mtb. A combination of these vitamins (RAVD) enhanced the receptors on THP-1 macrophage (Mannose receptor and DC-SIGN) that increased mycobacterial uptake but inhibited the
subsequent intracellular growth of Mtb by inducing reactive oxygen species (ROS) and autophagy. RAVD also enhanced antigen presenting and homing receptors in THPs that suggested an activated phenotype for THPs following RAVD treatment. RAVD mediated activation was also associated with a marked phenotypic change in Mtb …

Multiple Posttranscriptional Regulatory Features Control Expression Of Ethanolamine Utilization Genes In Enterococcus Faecalis, Kristina A. Fox

Dissertations and Theses (Open Access)

Enterococcus faecalis is a Gram-positive bacterium that lives as a commensal organism in the mammalian gastrointestinal tract, but can behave as an opportunistic pathogen.  Our lab discovered that mutation of the eutK gene attenuates virulence of E. faecalis in the C. elegans model host.  eutK is part of the ethanolamine metabolic pathway which was previously unknown in E. faecalis.  I discovered the presence of two unique posttranscriptional regulatory features that control expression of eut locus genes.  The first feature I found is an AdoCBL riboswitch, a cis-acting RNA regulatory element that acts as a positive regulator of gene …

Activities Of Muscadine Grape Skin And Polyphenolic Constituents Against Helicobacter Pylori, Joseph Brown

All Dissertations

Helicobacter pylori is a microaerophilic, gram-negative bacterium and among the most persistent of all human pathogens. Its presence in the gastric environment is corre-lated with diseases such as gastritis, peptic ulcers, mucosa-associated lymphoid tissue lymphoma, and gastric carcinoma. Multiple factors are believed responsible for disease progression and outcome including infecting strain(s) genetic composition, age of acqui-sition, host immune response, environment, and diet. Due to the complexity of H. pylori infection, all possible host-pathogen interactions should be considered. One important factor frequently underplayed is host dietary habits which may serve a more important role during and immediately following infection with H. …

Stress Response And Pathogenesis Of Salmonella Enterica Serovar Typhimurium, Jigna D. Shah

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Salmonella is a food-borne pathogen that leads to substantial illness worldwide. The clinical syndromes associated with Salmonella infection are enteric (typhoid) fever and gastroenteritis, in healthy humans. Typhoid fever is caused by host-adapted S. Typhi and S. Paratyphi. Gastroenteritis is caused by serovars usually referred to as non typhoidal Salmonellae (NTS). In recent years, an increasing number of outbreaks due to NTS, despite increased efforts in food safety, were reported because of persistence of Salmonella in the food chain. Thus I hypothesized that Salmonella is able to withstand stresses in the environment and treatments used during food processing …

Knowledge And Beliefs Among Health Care Workers Regarding Hepatitis B Infection And Needle Stick Injuries At A Tertiary Care Hospital, Karachi, Faiza Habib, Durreshahwar K Khan, Shan-E-Abbas, Faiza Bhatti, Afia Zafar

Department of Pathology and Laboratory Medicine

Hepatitis B virus (HBV) infection is a recognized occupational risk for health care workers (HCWs). This study aimed to assess the knowledge and beliefs of HCWs regarding HBV transmission and needle stick injuries (NSIs). A cross-sectional questionnaire based KAP study was conducted at Civil Hospital, Karachi, during the period of January to September 2006. HCWs were inquired about possible modes of HBV transmission and association with NSIs. Data were entered using EpiInfo 6.04d software. Statistical analysis was performed using SPSS 12.5 software. A total of 343 HCWs participated, and those answered at least 5 correct modes of HBV transmission were …

Elevated Expression Of Squamous Cell Carcinoma Antigen (Scca) Is Associated With Human Breast Carcinoma, Joseph M. Catanzaro, Jennifer L. Guerriero, Jingxuan Liu, Namratha Sheshadri, John J. Chen, Wei-Xing Zhong

Department of Molecular Genetics and Microbiology Faculty Publications

Squamous cell carcinoma antigen (SCCA) belongs to the serine protease inhibitor (Serpin) family of proteins. Elevated expression of SCCA has been used as a biomarker for aggressive squamous cell carcinoma (SCC) in cancers of the cervix, lung, head and neck, and liver. However, SCCA expression in breast cancer has not been investigated. Immunohistochemical analysis of SCCA expression was performed on tissue microarrays containing breast tumor tissues (n = 1,360) and normal breast epithelium (n = 124). SCCA expression was scored on a tiered scale (0-3) independently by two evaluators blind to the patient's clinical status. SCCA expression was observed in …

Reactivation Phenotypes Of Parent Strain And Four Viral Constructs In The Murine Hyperthermia Reactivation Model For Herpes Simplex Virus-1, Jason Hardcastle

Student Theses and Dissertations

Herpes simplex virus-1 (HSV-1) is the source of non-genital herpes infections in humans. The host typically suffers an acute infection followed by latency, in which the host appears asymptomatic as the virus remains present within the host. The virus can reactivate, usually due to physiological stress of the host, which once again becomes symptomatic of herpes. This study examines the role of the reactivation critical region (RCR) by removing a 348-base pair (bp) region transcribing latency-associated transcripts (LAT) from the wild-type HSV-1 strain (17syn+). Upon reactivation, the mice infected with the 17syn+ strain exhibited an 89% reactivation rate while the …

Partnership For International Research And Education In Microfluidic Technology With Applications In Point Of Care Diagnostic, Mohammed Faghri, Sigrid Berka, John Grandin, Thomas Mather, D.M.L Meyer, Zongqin Zhang, Otto Gregory, Stephan Grilli, Christopher Baxter, Constantine Anagnostopoulos, Assem Abolmaaty

Discovery@URI

This poster summarizes the research highlights of a project conducted as part of an National Science Foundation (NSF) partnership for research and education. The objective of this multidisciplinary, international project was to conduct research on microfluidic technology and applications. The project team is comprised of participants from the University of Rhode Island and the Technical University of Braunschweig in Germany. The research focuses on the following four tasks: Task 1 – Discovery of disease biomarkers; Task 2 –Streaming based microfluidic platform for pumping, mixing, separation and detection; Task 3 – Development of rapid, quantitative and sensitive microfluidic fluorescence immunosensors for …