Microbiology Commons^™

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 …

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 …

Community-Acquired Methicillin-Resistant Staphylococcus Aureus (Ca-Mrsa) Usa300 Perturbs Acquisition Of Lysosomal Hydrolases And Requires Phagosomal Acidification For Survival In A Human Macrophage Cell Line, Zachary Ronald Tranchemontagne

All Theses And Dissertations

Community-acquired Methicillin-resistant Staphylococcus aureus (CA-MRSA) strain USA300 is a major cause of invasive drug-resistant skin and soft tissue infections in humans. Although S. aureus is a well-recognized extracellular pathogen, recent reports that USA300 survives inside host macrophages suggest that the intramacrophage environment may be a niche for persistent infection. Intramacrophage survival requires bacteria to avoid destruction in the phagosome; however, mechanisms by which USA300 evades phagosomal defenses are unclear. We examined the fate of the USA300-containing phagosome in human THP-1 macrophages by evaluating phagosomal acidification and maturation, and by testing the impact of phagosomal conditions on bacterial viability. Utilizing confocal …

Identification Of Genes Required To Synthesize An Antibiotic-Like Compound From The Soil Bacterium Rhodococcus Sp. Mtm3w5.2, Amber L. Ward

Electronic Theses and Dissertations

Rhodococcus is a soil bacterium, member of the Actinobacteria, and a close relative of the prolific small molecule producer Streptomyces. Recent interest in Rhodococcus as an under investigated source of possible bioactive secondary metabolites is sparked by the discovery of many polyketide synthase and non-ribosomal peptide synthetase genes of unknown function from sequenced Rhodococcus genomes. Rhodococcus species strain MTM3W5.2 was recently shown to produce a strong inhibitory compound with activity against most strains of Rhodococcus and closely related genera. A goal of this investigation is to discover the gene(s) required to synthesize this inhibitory molecule. The engineered Rhodococcus …

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 …

Investigations Of Filarial Nematode Motility, Response To Drug Treatment, And Pathology, Charles Nutting

Dissertations

More than a billion people live at risk of chronic diseases caused by parasitic filarial nematodes. These diseases: lymphatic filariasis, onchocerciasis, and loaisis cause significant morbidity, degrading the health, quality of life, and economic productivity of those who suffer from them. Though treatable, there is no cure to rid those infected of adult parasites. The parasites can modulate the immune system and live for 10-15 years. Testing of compounds against filarial nematodes is complicated due to a lack of an objective platform on which to analyze in vitro treatments. There is no published, immunocompetent laboratory model for lymphatic filariasis. This …

The Role Of Sulfur Metabolism In Effective Plant-Microbe Interactions, Justin Joseph Speck

Theses and Dissertations

Bradyrhizobium japonicum USDA110 and Sinorhizobium meliloti RM1021 are nitrogen fixing rhizobia that fix nitrogen when in a symbiotic relationship with legumes. For effective nitrogen-fixing symbiosis to occur these rhizobia must differentiate into nitrogen-fixing bacteroids. This involves the production of high levels of sulfur rich nitrogenase as well as other sulfur containing compounds, creating a large demand for sulfur. This work examined the role of organic sulfur in the establishment of symbiosis and viability of rhizobia in plant nodules.

Disruption of the sulfonate sulfur utilization gene ssuD in both Bradyrhizobium japonicum USDA110 and Sinorhizobium meliloti RM1021 resulted in a strong nitrogen …

Coxiella Burnetii And Leishmania Mexicana Residing Within Similar Parasitophorous Vacuoles Elicit Disparate Host Responses, Jess A. Millar, Raquel Valdés, Fenil Kacharia, Scott M. Landfear, Eric D. Cambronne, Rahul Raghavan, Lynn Soong, Emilio Luis Malchiodi

Biology Faculty Publications and Presentations

Coxiella burnetii is a bacterium that thrives in an acidic parasitophorous vacuole (PV) derived from lysosomes. Leishmania mexicana, a eukaryote, has also independently evolved to live in a morphologically similar PV. As Coxiella and Leishmania are highly divergent organisms that cause different diseases, we reasoned that their respective infections would likely elicit distinct host responses despite producing phenotypically similar parasite-containing vacuoles. The objective of this study was to investigate, at the molecular level, the macrophage response to each pathogen. Infection of THP-1 (human monocyte/macrophage) cells with Coxiella and Leishmania elicited disparate host responses. At 5 days post-infection, when …

Kaposi’S Sarcoma-Associated Herpesvirus Transmission And Infection Among Young Zambian Children, Landon Olp

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

Kaposi’s sarcoma-associated herpesvirus (KSHV) is the etiologic agent for all forms of Kaposi’s sarcoma (KS)—one of the most common pediatric cancers in sub-Saharan Africa during the AIDS epidemic. KS was endemic in sub-Saharan Africa prior to the HIV/AIDS epidemic, but KS cases drastically increased thereafter. Our laboratory previously observed that KSHV infection is common among Zambian children and saliva is the major route of transmission. However, additional factors associated with the transmission of KSHV to children are poorly understood. Since a vaccine against KSHV is not currently available, it is paramount to understand factors associated with transmission so that alternative …

Beyond Bivariate Correlations: Three-Block Partial Least Squares Illustrated With Vegetation, Soil, And Topography, Daehyun Kim, Thomas J. Dewitt, César S. B. Costa, John A. Kupfer, Ryan W. Mcewan, J. Anthony Stallins

Biology Faculty Publications

Ecologists, particularly those engaged in biogeomorphic studies, often seek to connect data from three or more domains. Using three-block partial least squares regression, we present a procedure to quantify and define bi-variance and tri-variance of data blocks related to plant communities, their soil parameters, and topography. Bi-variance indicates the total amount of covariation between these three domains taken in pairs, whereas tri-variance refers to the common variance shared by all domains. We characterized relationships among three domains (plant communities, soil properties, topography) for a salt marsh, four coastal dunes, and two temperate forests spanning several regions in the world. We …

Regulation Of Vancomycin Resistance And Stress Response By The Msaabcr Operon In Staphylococcus Aureus, Dhritiman Samanta

Dissertations

Staphylococcus aureus is the predominant cause of public health problems around the world. Vancomycin has been an important antibiotic against Methicillin Resistant Staphylococcus aureus (MRSA) infections. However, Vancomycin Intermediate S. aureus (VISA) strains have been reported. These strains are characterized by thick cell walls, reduced autolytic rate, reduced PBP4 activity, and increased amount of D-Ala-D-Ala termini in the cell wall. In this study, we show that the msaABCR operon regulates vancomycin resistance in two clinical VISA strains. Deletion of the msaABCR operon in strains Mu50 and HIP6297 resulted in a significant decrease in the minimum inhibitory concentration (MIC) for vancomycin. …

Geochemical Control Of Methanogenesis In Cape Lookout Bight, North Carolina, Richard Kevorkian

Masters Theses

Hydrogen exerts thermodynamic control over the exclusion of methanogens by sulfate reducers in Cape Lookout Bight, NC, marine sediments. This has been demonstrated by previous in situ measurements, but has never been demonstrated in a batch incubation of unamended sediments and has never been combined with identification of the microorganisms involved in this process. We made triplicate anoxic incubations of sediments from the upper 3 cm of sediment over 122 days while taking weekly samples for DNA extraction, cell counts, and measurements of methane, sulfate, and hydrogen. The headspaces of the bottles were initially gassed with nitrogen and the third …

Gene Regulation By A Novel Two-Component System Conserved Among Gammaproteobacteria, Kristin M. Jacob

All NMU Master's Theses

Two-component systems are common gene regulatory pathways seen in bacteria. Gene expression is controlled by these systems through a series of phosphorylation events between two proteins, a membrane bound sensor kinase and a cytoplasmic response regulator. Activation of a two-component system can be caused by biological or environmental stimuli, resulting in altered gene expression. A conserved two-component system was recently discovered in entomopathogenic bacteria, including our model organisms Pseudomonas entomophila and Pseudomonas aeruginosa, and is homologous to the recently identified two-component system, CrbRS, in Vibrio cholerae. In V. cholerae CrbRS regulates acetate metabolism and controls virulence. The aim of this …

Cultivation-Dependent Analysis Of Microorganisms Associated With Various Hydraulic Fracturing Fluids, Anthony Harrington

UNLV Theses, Dissertations, Professional Papers, and Capstones

The overarching goal of this study is to gain more insight to the microbial interactions associated with hydraulic fracturing by studying the culturable microorganisms present in various types of hydraulic fracturing fluids. Extraction of natural gas and other unconventional resources using hydraulic fracturing has increased in the last decade and very few studies have been conducted on the microorganisms associated with the various water types used in the process. From the very few published studies, the only cultivation-dependent method used involved determining the most probable number (MPN) of various metabolic groups, however the researchers failed to ask more in-depth questions …

The Effects Of Honeybee (Apis Mellifera) Antimicrobial Peptides On Paenibacillus Larvae, Jasmin Camille Khilnani

UNLV Theses, Dissertations, Professional Papers, and Capstones

American Foulbrood Disease (AFB) is the most detrimental bacterial disease that affects honeybee larvae (Apis mellifera) worldwide. The etiological agent of AFB is the Gram-positive, spore-forming bacterial pathogen, Paenibacillus larvae. Treatment with antibiotics, specifically oxytetracycline, has led to the development of antibiotic resistance in P. larvae. Therefore, there is a pressing need for an alternative treatment method. The overall goal of this project was to test naturally occurring, active antimicrobial peptides (AMPs), which are produced in the adult honeybee, against vegetative P. larvae. These active AMPs could potentially be used as a prophylactic treatment to prevent P. larvae infection of …

Symptomatic Surgically Treated Non-Neoplastic Cysts Of The Central Nervous System: A Clinicopathological Study From Pakistan, Nasir Ud Din, Huma Arshad, Zubair Ahmad, Sheema H Hasan, Mohammad Ehsan Bar

Department of Pathology and Laboratory Medicine

Objective: To report clinicopathologic features of symptomatic surgically removed non-neoplastic cysts of the central nervous system (CNS). Study Design: Case series. Place and Duration of Study: The Aga Khan University Hospital, Karachi, from 2003 to 2012. Methodology: All non-neoplastic CNS cysts reported during the study period were retrieved and reviewed. Age, gender, location, histologic type and clinical features were noted. Results: A total of 124 cysts were diagnosed in the study period. These included 44 epidermoid cysts (mean age 30.5 ± 13.8 years), 35 colloid cysts (mean age 31 ± 13.2 years), 32 arachnoid cysts (mean age 24.8 ± 20.2 …

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, …

Algr Directly Controls Rsma In Pseudomonas Aeruginosa, Tyler Speaks

Electronic Theses and Dissertations

Pseudomonas aeruginosa is a bacterial pathogen that can infect any human tissue. The lungs of cystic fibrosis patients become chronically infected with Pseudomonas aeruginosa. Virulence factor gene expression is under elaborate regulatory control that remains poorly characterized. Understanding the regulatory hierarchy involved during infection is essential for identifying novel drug targets. RsmA is a post-transcriptional regulatory protein that controls expression of several virulence factors. Previous studies demonstrated alginate regulatory components AlgU and AlgR as regulators of rsmA expression. The aim of this study was to determine how AlgR controls rsmA expression. Western blot analysis of HA-tagged RsmA confirmed lower …

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 …