Microbiology Commons^™

The Effects Of Electrostatic Spraying With Organic Acids In The Disintegration Of Biofilms Formed By E.Coli O157:H7 And Salmonella Typhimurium On Spinach And Cantaloupe, Ahmad Almasoud

Graduate Theses and Dissertations

Outbreaks from the consumption of fresh produce are a concern in the United States. The consumptions of fresh produce have increased recently which expose a large segment of society to such outbreaks. Spinach and cantaloupe are minimally heated or processed before consumption which makes them a possible source of foodborne illness. The objective of this research was to investigate the effect of organic acids alone and in combination to reduce attached Salmonella Typhimurium (S.T) and Escherichia coli O157:H7 (E.coli) on spinach and cantaloupe, and to disintegrate biofilm formed by these pathogens by electrostatically spraying with two organic acids. To quantify …

Stressed Induced Changes In Karenia Brevis Ribosomal Rna, David Scott Jayroe

Master's Theses

Karenia brevis is a toxic marine dinoflagellate that causes harmful algal blooms (HABs), also known as red tides, in the Gulf of Mexico. These blooms are responsible for massive fish kills, shellfish bed contaminations, adverse human health effects, and vast economic loss. For these reasons, extensive research has gone into understanding the mechanisms and dynamics of bloom behavior by studying K. brevis in the field and in the lab. In order to understand higher order bloom behavior and dynamics it is imperative to understand K. brevis at the cellular level. In growing K. brevis in vitro under a variety of …

Impacts Of The Deepwater Horizon Oil Spill On Microbial-Mediated Cellulose Decomposition In Mississippi Gulf Coast Salt Marshes, Jerrid Shawn Boyette

Master's Theses

Field studies were conducted to examine the effects of the Deepwater Horizon oil spill on rates of marsh organic matter decomposition. Decomposition in surface and subsurface marsh sediments was assessed in stands of Spartina alterniflora and Juncus roemerianus in 9 Mississippi Gulf Coast marshes exposed to differing oiling intensities. The cotton strip bioassay technique was used as a proxy for cellulose decomposition. In addition, rates of microbial respiration, fungal biomass (ergosterol) and nutrients (C:N, C:P) of surface sediment cotton strips were also quantified. Subsurface cotton strip decay, as determined by losses in tensile strength, were significantly different among marsh …

How Does The Exploitation And Degradation Of Finite Natural Resources By Industrial Oil Producers Effect Our Future Planetary Environment?, Zachary J. King Mr.

Symposium of Student Scholars

Zachary King

Dr. Tu

26 March 2015

GEOG 3700

Abstract

The purpose of this presentation is to communicate content of the reports given by credible institution on the degradation and exploitation of finite natural resources by corporate institutions, for short term financial gain, and how it will effect the future planetary environment. Methods used in obtaining this research range from point source observation directly from oil spills in the Gulf or pipe leaks in the Mid-West, to analytical and numerical data quantifications gathered over a period of two decades. This presentation encompasses a wide scope of information concerning the way …

Is There Specificity In A Defensive Mutualism Against Soil Versus Lab Nematodes, Dictyostelium Discoideum Farmers And Their Bacteria?, Boahemaa Adu-Oppong,, David C. Queller, Joan E. Strassmann

Biology Faculty Research

Background: The social amoeba Dictyostelium discoideum is a soil-dwelling microbe, which lives most of its life cycle in the vegetative stage as a predator of bacteria and as prey for nematodes. When bacteria are sparse, amoebae aggregate into a multicellular fruiting body. Some clones of D. discoideum have agriculture (Brock et al., 2011). They carry bacteria through the social stage, eat them prudently, and use some bacteria as defence against non-farming D. discoideum competitors. Caenorhabditis elegans preys on D. discoideum in the laboratory but does not encounter it in nature because C. elegans lives on rotten fruit. The nematode …

Viral Bimolecular Fluorescence Complementation: A Novel Tool To Study Intracellular Vesicular Trafficking Pathways, Brennan S Dirk, Rajesh Abraham Jacob, Aaron L Johnson, Emily N Pawlak, P Craig Cavanagh, Logan Van Nynatten, S M Mansour Haeryfar, Jimmy D. Dikeakos

Microbiology & Immunology Publications

The Human Immunodeficiency Virus type 1 (HIV-1) accessory protein Nef interacts with a multitude of cellular proteins, manipulating the host membrane trafficking machinery to evade immune surveillance. Nef interactions have been analyzed using various in vitro assays, co-immunoprecipitation studies, and more recently mass spectrometry. However, these methods do not evaluate Nef interactions in the context of viral infection nor do they define the sub-cellular location of these interactions. In this report, we describe a novel bimolecular fluorescence complementation (BiFC) lentiviral expression tool, termed viral BiFC, to study Nef interactions with host cellular proteins in the context of viral infection. Using …

True Durability: Hiv Virologic Suppression In An Urban Clinic And Implications For Timing Of Intensive Adherence Efforts And Viral Load Monitoring, Debra A. Benator, Angelo Elmi, Manuel D. Rodriguez, Howard B. Gale, Virginia L. Kan, Heather J. Hoffman, Susan Tramazzo, Karen Hall, Angela Mcknight, Leah Squires

Medicine Faculty Publications

Although the majority of HIV-infected patients who begin potent antiretroviral therapy should expect long-term virologic suppression, the realities in practice are less certain. Durability of viral suppression was examined to define the best timing of targeted adherence strategies and intensive viral load monitoring in an urban clinic population with multiple challenges to ART adherence. We examined the risk of viral rebound for patients who achieved two consecutive viral loads lower than the lower limit of quantification (LLOQ) within 390 days. For 791 patients with two viral loads below the LLOQ, viral rebound >LLOQ from the first viral load was 36.9 …

True Durability: Hiv Virologic Suppression In An Urban Clinic And Implications For Timing Of Intensive Adherence Efforts And Viral Load Monitoring., Debra A Benator, Angelo Elmi, Manuel D Rodriguez, Howard B Gale, Virginia L. Kan, Heather J. Hoffman, Susan Tramazzo, Karen Hall, Angela Mcknight, Leah Squires

Medicine Faculty Publications

Although the majority of HIV-infected patients who begin potent antiretroviral therapy should expect long-term virologic suppression, the realities in practice are less certain. Durability of viral suppression was examined to define the best timing of targeted adherence strategies and intensive viral load monitoring in an urban clinic population with multiple challenges to ART adherence. We examined the risk of viral rebound for patients who achieved two consecutive viral loads lower than the lower limit of quantification (LLOQ) within 390 days. For 791 patients with two viral loads below the LLOQ, viral rebound >LLOQ from the first viral load was 36.9 …

Exploring The Physiological Role Of Vibrio Fischeri Pepn, Sally L. Cello

Master's Theses

The primary contributor to Vibrio fischeri aminopeptidase activity is aminopeptidase N, PepN. Colonization assays revealed the pepN mutant strain to be deficient at forming dense aggregates and populating the host’s light organ compared to wildtype within the first 12 hours of colonization; however the mutant competed normally at 24 hours. To address the role of PepN in colonization initiation and establish additional phenotypes for the pepN mutant strain, stress response and other physiological assays were employed. Marked differences were found between pepN mutant and wildtype strain in response to salinity, acidity, and antibiotic tolerance. This study has provided a foundation …

The Evolutionary Origination And Diversification Of A Dimorphic Gene Regulatory Network Through Parallel Innovations In Cis And Trans, Eric M. Camino, John C. Butts, Alison J. Ordway, Jordan E. Vellky, Mark Rebeiz, Thomas M. Williams

Biology Faculty Publications

The origination and diversification of morphological characteristics represents a key problem in understanding the evolution of development. Morphological traits result from gene regulatory networks (GRNs) that form a web of transcription factors, which regulate multiple cis-regulatory element (CRE) sequences to control the coordinated expression of differentiation genes. The formation and modification of GRNs must ultimately be understood at the level of individual regulatory linkages (i.e., transcription factor binding sites within CREs) that constitute the network. Here, we investigate how elements within a network originated and diversified to generate a broad range of abdominal pigmentation phenotypes among Sophophora fruit flies. …

Cell Type-Specific Responses To Wingless, Hedgehog And Decapentaplegic Are Essential For Patterning Early Eye-Antenna Disc In Drosophila, Jong-Hoon Won, Orkhon Tsogtbartarr, Wonseok Son, Amit Singh, Kwang-Wook Choi, Kyung-Ok Cho

Biology Faculty Publications

The Drosophila eye-antenna imaginal disc (ead) is a flattened sac of two-layered epithelia, from which most head structures are derived. Secreted morphogens like Wingless (Wg), Hedgehog (Hh), and Decapentaplegic (Dpp) are important for early patterning of ead, but the underlying mechanisms are still largely unknown. To understand how these morphogens function in the ead of early larval stages, we used wg-LacZ and dpp-Gal4 markers for the examination of wild-type and mutant eads. We found that the ead immediately after hatching was crescent-shaped with the Bolwig’s nerve at the ventral edge, suggesting that it consists of dorsal domain. In a subsequent …

Concurrent Coevolution Of Intra-Organismal Cheaters And Resisters, S R. Levin, D A. Brock, David C. Queller, Joan E. Strassmann

Biology Faculty Research

The evolution of multicellularity is a major transition that is not yet fully understood. Specifically, we do not know whether there are any mechanisms by which multicellularity can be maintained without a single-cell bottleneck or other relatedness-enhancing mechanisms. Under low relatedness, cheaters can evolve that benefit from the altruistic behaviour of others without themselves sacrificing. If these are obligate cheaters, incapable of cooperating, their spread can lead to the demise of multicellularity. One possibility, however, is that cooperators can evolve resistance to cheaters. We tested this idea in a facultatively multicellular social amoeba, Dictyostelium discoideum. This amoeba usually exists as …

Human Impacts On Water Systems: Biological Assessment Of Water Quality In The Bosque Protector Río Guajalito (Bprg) Using Aquatic Macroinvertebrates, Harrison Smith

Independent Study Project (ISP) Collection

Benthic macroinvertebrates have been extensively used as bioindicators for water quality due to their varying sensitivity to a diverse range of impacts on hydrographic sources. In this study a sampling of macroinvertebrates was carried out in the Guajalito and Brincador rivers and a small creek that runs through the private reserve Bosque Protector Rio Guajalito in order to analyze if the health of the rivers has changed in relation to previous studies. The sampling stations were located upstream and downstream of potential sources of disturbance in each of the three streams sampled in order to determine what level of impact …

Potential For Biocontrol Of Environmental Vibrio Spp. By Predatory Bacteria Bacteriovorax, Patrick Tennis

OES Theses and Dissertations

The scale of predator-prey interactions varies from the iconic (e.g., lions and gazelles) to the microscopic (e.g., protists and bacteria). Bdellovibrio-and-like-organisms (BALOs) are bacteria that prey upon other Gram-negative bacteria, including pathogens. In particular, the halophilic genus Vibrio, many species of which are disease agents, has been shown to be susceptible to attack by BALOs. One motivation of the present research is to assess the potential for biocontrol of Vibrio by Bacteriovorax. This investigation is the first to test the susceptibility of Vibrio strains (n = 26) originating from a variety of geographic locations to predation by …

The Role And Regulation Of Quinol Oxidase In Rhizobium Etli, Zachary Ryan Lunak

Dissertations (1934 -)

Aerobic bacteria typically respire by delivering electrons to oxygen via cytochrome c oxidases. In addition, many bacteria can respire by transferring electrons to oxygen via quinol oxidases. Exactly why bacteria contain quinol oxidases when they already have cytochrome c oxidases is unclear. In particular, the Cyo quinol oxidase, encoded by cyoABCD, is widespread among the dominant bacterial groups but its specific role is unknown. Rhizobium etli CFN42 provides an aerobic respiratory model in which Cyo can be directly compared to cytochrome c oxidases within the same organism. Mutants of the terminal oxidases in R. etli were constructed and their ability …

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 …

Induction Of Anti-Microbial Immune Responses In Severely Immunodeficient Hosts By Ifn-Expressing Salmonella Enterica Serovar Typhimurium Correlates With Efficient Activation Of Macrophage Effectors, Mohammed Achraf Al-Sbiei This

Theses

Susceptibility to infection by the intracellular bacterial pathogen, Salmonella enterica serovar Typhimurium (S. typhimurium), is controlled by many genes of innate and adaptive immunity. One of the most critical genes is IFN- and mice deficient in IFN- synthesis are highly susceptible to Salmonella. Previously, we demonstrated that mice deficient in MyD88, an adaptor that regulates TLR signaling, are susceptible to Salmonella infection. In the current study, we compared immune responses in mice deficient in IFN- or MyD88 with wild-type controls following infection with an attenuated strain of S. typhimurium (designated BRD509E) or a recombinant derivative engineered to express murine IFN- …

Marine Sequestration Of Carbon In Bacterial Metabolites, Oliver J. Lechtenfeld, Norbert Hertkorn, Yuan Shen, Matthias Witt, Ronald Benner

Faculty Publications

Linking microbial metabolomics and carbon sequestration in the ocean via refractory organic molecules has been hampered by the chemical complexity of dissolved organic matter (DOM). Here, using bioassay experiments and ultra-high resolution metabolic profiling, we demonstrate that marine bacteria rapidly utilize simple organic molecules and produce exometabolites of remarkable molecular and structural diversity. Bacterial DOM is similar in chemical composition and structural complexity to naturally occurring DOM in sea water. An appreciable fraction of bacterial DOM has molecular and structural properties that are consistent with those of refractory molecules in the ocean, indicating a dominant role for bacteria in shaping …

Role Of Epstein-Barr Virus Induced Gene Ii (Ebi2) In Epstein-Barr Virus Infection And B-Cell Chemotaxis, Brian Poole

Journal of Undergraduate Research

The academic objectives of this proposal were met. Using the funding provided by the MEG, we generated data that was used to publish three peer-reviewed journal articles:

Post-Translational Modifications Of Thymidine Kinase 1, Dr. Kim O'Neill

Journal of Undergraduate Research

Thymidine kinase 1 (TK1) is one diagnostic and prognostic marker which has shown promising potential in a variety of solid tumors and hematological malignancies. Unfortunately there have been challenges associated with developing a clinically useful immunoassay which have prevented TK1 from being fully utilized in the clinical setting at present. One of the major goals of this study was to produce a dependable, reproducible, immunoassay to detect TK1 in serum from cancer patients. There have been many attempts at detecting protein or genetic material in the serum or sputum of lung cancer patients but these all have failed due to …