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Microbiology

2016

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Articles 1 - 30 of 632

Full-Text Articles in Life Sciences

Influence Of Maternal Breast Milk Ingestion On Acquisition Of The Intestinal Microbiome In Preterm Infants., Katherine E Gregory, Buck S Samuel, Pearl Houghteling, Guru Shan, Frederick M Ausubel, Ruslan I Sadreyev, W Allan Walker Dec 2016

Influence Of Maternal Breast Milk Ingestion On Acquisition Of The Intestinal Microbiome In Preterm Infants., Katherine E Gregory, Buck S Samuel, Pearl Houghteling, Guru Shan, Frederick M Ausubel, Ruslan I Sadreyev, W Allan Walker

Baylor Faculty Publications

BACKGROUND: The initial acquisition and early development of the intestinal microbiome during infancy are important to human health across the lifespan. Mode of birth, antibiotic administration, environment of care, and nutrition have all been shown to play a role in the assembly of the intestinal microbiome during early life. For preterm infants, who are disproportionately at risk of inflammatory intestinal disease (i.e., necrotizing enterocolitis), a unique set of clinical factors influence the establishment of the microbiome. The purpose of this study was to establish the influence of nutritional exposures on the intestinal microbiome in a cohort of preterm infants ...


Cullin-4 Regulates Wingless And Jnk Signaling-Mediated Cell Death In The Drosophila Eye., Meghana Tare, Ankita Sarkar, Shimpi Bedi, Madhuri Kango-Singh, Amit Singh Dec 2016

Cullin-4 Regulates Wingless And Jnk Signaling-Mediated Cell Death In The Drosophila Eye., Meghana Tare, Ankita Sarkar, Shimpi Bedi, Madhuri Kango-Singh, Amit Singh

Biology Faculty Publications

In all multicellular organisms, the fundamental processes of cell proliferation and cell death are crucial for growth regulation during organogenesis. Strict regulation of cell death is important to maintain tissue homeostasis by affecting processes like regulation of cell number, and elimination of unwanted/unfit cells. The developing Drosophila eye is a versatile model to study patterning and growth, where complex signaling pathways regulate growth and cell survival. However, the molecular mechanisms underlying regulation of these processes is not fully understood. In a gain-of-function screen, we found that misexpression of cullin-4 (cul-4), an ubiquitin ligase, can rescue reduced eye mutant phenotypes ...


Performance Of The G4 Xpert(R) Mtb/Rif Assay For The Detection Of Mycobacterium Tuberculosis And Rifampin Resistance: A Retrospective Case-Control Study Of Analytical And Clinical Samples From High- And Low-Tuberculosis Prevalence Settings, Nila J. Dharan, Robert Blakemore, Alexander Sloutsky, Devinder Kaur, Richard C. Alexander, Minoo Ghajar, Kimberlee A. Musser, Vincent E. Escuyer, Marie-Claire Rowlinson, Susanne Crowe, Rafael Laniado-Laborin, Eloise Valli, Pamela Nabeta, Pamela Johnson, David Alland Dec 2016

Performance Of The G4 Xpert(R) Mtb/Rif Assay For The Detection Of Mycobacterium Tuberculosis And Rifampin Resistance: A Retrospective Case-Control Study Of Analytical And Clinical Samples From High- And Low-Tuberculosis Prevalence Settings, Nila J. Dharan, Robert Blakemore, Alexander Sloutsky, Devinder Kaur, Richard C. Alexander, Minoo Ghajar, Kimberlee A. Musser, Vincent E. Escuyer, Marie-Claire Rowlinson, Susanne Crowe, Rafael Laniado-Laborin, Eloise Valli, Pamela Nabeta, Pamela Johnson, David Alland

Open Access Articles

BACKGROUND: The Xpert(R) MTB/RIF (Xpert) assay is a rapid PCR-based assay for the detection of Mycobacterium tuberculosis complex DNA (MTBc) and mutations associated with rifampin resistance (RIF). An updated version introduced in 2011, the G4 Xpert, included modifications to probe B and updated analytic software.

METHODS: An analytical study was performed to assess Xpert detection of mutations associated with rifampin resistance in rifampin-susceptible and -resistant isolates. A clinical study was performed in which specimens from US and non-US persons suspected of tuberculosis (TB) were tested to determine Xpert performance characteristics. All specimens underwent smear microscopy, mycobacterial culture, conventional ...


The Vibrio Cholerae Minor Pilin Tcpb Initiates Assembly And Retraction Of The Toxin-Coregulated Pilus, Dixon Ng, Tony Harn, Tuba Altindal, Subramania Kolappan, Jarrad Marles, Rajan Lala, Ingrid Spielman, Yang Gao, Caitlyn Hauke, Gabriela Kovacikova Dec 2016

The Vibrio Cholerae Minor Pilin Tcpb Initiates Assembly And Retraction Of The Toxin-Coregulated Pilus, Dixon Ng, Tony Harn, Tuba Altindal, Subramania Kolappan, Jarrad Marles, Rajan Lala, Ingrid Spielman, Yang Gao, Caitlyn Hauke, Gabriela Kovacikova

Open Dartmouth: Faculty Open Access Scholarship

Type IV pilus (T4P) systems are complex molecular machines that polymerize major pilin proteins into thin filaments displayed on bacterial surfaces. Pilus functions require rapid extension and depolymerization of the pilus, powered by the assembly and retraction ATPases, respectively. A set of low abundance minor pilins influences pilus dynamics by unknown mechanisms. The Vibrio cholerae toxin-coregulated pilus (TCP) is among the simplest of the T4P systems, having a single minor pilin TcpB and lacking a retraction ATPase. Here we show that TcpB, like its homolog CofB, initiates pilus assembly. TcpB co-localizes with the pili but at extremely low levels, equivalent ...


Toward The History Of Study Of Symbiogenesis: On The English Translation Of B. M. Kozo-Polyansky’S A New Principle Of Biology (1924), Victor Fet Dec 2016

Toward The History Of Study Of Symbiogenesis: On The English Translation Of B. M. Kozo-Polyansky’S A New Principle Of Biology (1924), Victor Fet

Victor Fet

We reproduce the text by Victor Fet, which was read on 6 October 2011 at the Moscow Society of Naturalists during the presentation of new book translation (B.M. Kozo- Polyansky. Symbiogenesis: A New Principle of Evolution / transl. by Victor Fet; ed. by Victor Fet & Lynn Margulis. Cambridge, Mass.: Harvard University Press, 2010. 138 p.) This half- forgotten book by Boris M. Kozo-Polyansky was known only by name to Western biologists. Victor Fet gives a brief history of this new translation, enthusiastically initiated and supported by Lynn Margulis (1938–2011), a famous naturalist who was always eager to gave credit where credit was due. Kozo- Polyansky, along with Merezhkovsky, Portier, and Wallin, pioneered symbiogenetic ideas that were brilliantly developed and vindicated starting from 1960–1970s. It was Lynn Margulis who noticed also that Kozo- Polyansky preceded E. Chatton in recognizing the profound diff erence between prokaryotes and eukaryotes; in fact, he maintained that this difference was due to symbiogenetic, complex nature of the eukaryotic cell! Two “scientistic” poems (in Russian) by Victor Fet are included, dedicated to all the prophets and martyrs of science.


Occurrence, Antibiotic Resistance, And Survival Of Fecal Enterococci In Turkey Litter, Steven Glynn Mcbride Ii Dec 2016

Occurrence, Antibiotic Resistance, And Survival Of Fecal Enterococci In Turkey Litter, Steven Glynn Mcbride Ii

Masters Theses

The United States Environmental Protection Agency’s National Water Quality Inventory and the Commonwealth of Virginia’s 305(b)/303(d) Water Quality Assessment Integrated Report show fecal bacteria to be the most common cause of impairment for both streams and estuaries. Human and animal sources have both been identified as significant contributors of pathogenic bacteria to surface waters. In this study, turkey litter from a farm in Shenandoah County, VA was surveyed for total culturable bacteria and total culturable enterococci before and after a transition to organic rearing practices. The enterococci were identified to species phenotypically using the Biolog ...


Amino Acid Catabolism In Staphylococcus Aureus, Cortney Halsey Dec 2016

Amino Acid Catabolism In Staphylococcus Aureus, Cortney Halsey

Theses & Dissertations

Staphylococcus aureus must rapidly adapt to a variety of carbon and nitrogen sources during invasion of a host. Within a staphylococcal abscess, preferred carbon sources such as glucose are limiting, suggesting S. aureus survives through the catabolism of secondary carbon sources. S. aureus encodes pathways to catabolize multiple amino acids including those that generate pyruvate, 2-oxoglutarate, and oxaloacetate. To assess amino acid catabolism, S. aureus JE2 and mutants were grown in complete defined medium containing 18 amino acids but lacking glucose (CDM). A mutation in glutamate dehydrogenase (gudB), which generates 2-oxoglutarate from glutamate, abrogated growth in CDM suggesting that glutamate ...


High Epstein-Barr Virus Load And Genomic Diversity Are Associated With Generation Of Gp350-Specific Neutralizing Antibodies Following Acute Infectious Mononucleosis, Eric R. Weiss, Galit Alter, Javier Gordon Ogembo, Jennifer L. Henderson, Barbara Tabak, Yasin Bakis, Mohan Somasundaran, Manuel Garber, Liisa K. Selin, Katherine Luzuriaga Dec 2016

High Epstein-Barr Virus Load And Genomic Diversity Are Associated With Generation Of Gp350-Specific Neutralizing Antibodies Following Acute Infectious Mononucleosis, Eric R. Weiss, Galit Alter, Javier Gordon Ogembo, Jennifer L. Henderson, Barbara Tabak, Yasin Bakis, Mohan Somasundaran, Manuel Garber, Liisa K. Selin, Katherine Luzuriaga

Garber Lab Publications

The Epstein-Barr virus (EBV) gp350 glycoprotein interacts with the cellular receptor to mediate viral entry and is thought to be the major target for neutralizing antibodies. To better understand the role of EBV-specific antibodies in the control of viral replication and the evolution of sequence diversity, we measured EBV gp350-specific antibody responses and sequenced the gp350 gene in samples obtained from individuals experiencing primary EBV infection (acute infectious mononucleosis [AIM]) and again 6 months later (during convalescence [CONV]). EBV gp350-specific IgG was detected in the sera of 17 (71%) of 24 individuals at the time of AIM and all 24 ...


The Influence Of The Invasive Chinese Tallow (Triadica Sebifera) Leaf Litter On Aquatic Chemistry And Microbial Community Composition, Raymond D. Montez Dec 2016

The Influence Of The Invasive Chinese Tallow (Triadica Sebifera) Leaf Litter On Aquatic Chemistry And Microbial Community Composition, Raymond D. Montez

Electronic Theses and Dissertations

Global climate change and anthropogenic activity have facilitated the movement and invasive potential of nonnative plants in native environments. These invasions can have negative effects on ecosystem diversity and function. The nonnative and invasive plant, Chinese Tallow (Triadica sebifera), has already invaded much of the south eastern US where it is outcompeting native tree species and changing ecosystem diversity in a variety of habitats. Leaf litter from the Chinese tallow has been shown cause changes in dissolved oxygen and pH in the aquatic environment. Turbidity is also affected when Chinese tallow litter is present in water. A series of experiments ...


Jmh Dissertation 2016.Pdf, Jennifer Hayashi Dec 2016

Jmh Dissertation 2016.Pdf, Jennifer Hayashi

Jennifer Hayashi

Mycobacterium is a diverse genus of actinobacteria that includes the causative agents of human tuberculosis and leprosy. Mycobacteria are protected by their unique, multilaminar cell envelope, which grants them intrinsic resistance to environmental challenges such as antibiotics. This essential cellular structure is elongated at the polar ends of cells, but the regulation of cytosolic precursor synthesis and localized envelope synthesis remains unclear. Here, we present the PMf (plasma membrane free of cell wall components), a membrane domain distinct from the bulk plasma membrane of Mycobacterium smegmatis. Proteomic and lipidomic characterization demonstrate that the PMf contains lipidic substrates ...


Persistent Low-Level Replication Of Sivdeltanef Drives Maturation Of Antibody And Cd8 T Cell Responses To Induce Protective Immunity Against Vaginal Siv Infection, Sama Adnan, Wenjun Li, R. Paul Johnson Dec 2016

Persistent Low-Level Replication Of Sivdeltanef Drives Maturation Of Antibody And Cd8 T Cell Responses To Induce Protective Immunity Against Vaginal Siv Infection, Sama Adnan, Wenjun Li, R. Paul Johnson

Open Access Articles

Defining the correlates of immune protection conferred by SIVDeltanef, the most effective vaccine against SIV challenge, could enable the design of a protective vaccine against HIV infection. Here we provide a comprehensive assessment of immune responses that protect against SIV infection through detailed analyses of cellular and humoral immune responses in the blood and tissues of rhesus macaques vaccinated with SIVDeltanef and then vaginally challenged with wild-type SIV. Despite the presence of robust cellular immune responses, animals at 5 weeks after vaccination displayed only transient viral suppression of challenge virus, whereas all macaques challenged at weeks 20 and 40 post-SIVDeltanef ...


Review Of The Cultivation Program Within The National Alliance For Advanced Biofuels And Bioproducts, Peter J. Lammers, Michael Huesemann, Wiebke Boeing, Daniel B. Anderson, Robert G. Arnold, Xuemei Bai, Manish Bhole, Yalini Brhanavan, Louis Brown, Jola Brown, Judith K. Brown, Stephen Chisholm, C. Meghan Downes, Scott Fulbright, Yufeng Ge, Jonathan E. Holladay, Balachandran Ketheesan, Avinash Khopkar, Ambica Koushik, Paul Laur, Babetta L. Marrone, John B. Mott, Nagamany Nirmalakhandan, Kimberly L. Ogden, Ronald L. Parsons, Juergen Polle, Randy D. Ryan, Tzachi Samocha, Richard T. Sayre, Mark Seger, Thinesh Selvaratnam, Ruixiu Sui, Alex Thomasson, Adrian Unc, Wayne Van Vorrhies, Peter Waller, Yao Yao, José A. Olivares Dec 2016

Review Of The Cultivation Program Within The National Alliance For Advanced Biofuels And Bioproducts, Peter J. Lammers, Michael Huesemann, Wiebke Boeing, Daniel B. Anderson, Robert G. Arnold, Xuemei Bai, Manish Bhole, Yalini Brhanavan, Louis Brown, Jola Brown, Judith K. Brown, Stephen Chisholm, C. Meghan Downes, Scott Fulbright, Yufeng Ge, Jonathan E. Holladay, Balachandran Ketheesan, Avinash Khopkar, Ambica Koushik, Paul Laur, Babetta L. Marrone, John B. Mott, Nagamany Nirmalakhandan, Kimberly L. Ogden, Ronald L. Parsons, Juergen Polle, Randy D. Ryan, Tzachi Samocha, Richard T. Sayre, Mark Seger, Thinesh Selvaratnam, Ruixiu Sui, Alex Thomasson, Adrian Unc, Wayne Van Vorrhies, Peter Waller, Yao Yao, José A. Olivares

Publications and Research

The cultivation efforts within the National Alliance for Advanced Biofuels and Bioproducts (NAABB)were developed to provide four major goals for the consortium, which included biomass production for downstream experimentation, development of new assessment tools for cultivation, development of new cultivation reactor technologies, and development of methods for robust cultivation. The NAABB consortium test beds produced over 1500 kg of biomass for downstream processing. The biomass production included a number of model production strains, but also took into production some of the more promising strains found through the prospecting efforts of the consortium. Cultivation efforts at large scale are intensive ...


Erratum To: Neonatal Hyperbilirubinemia In Infants With G6pd C.563c>T Variant, Bushra Moiz, Amna Nasir, Sarosh Ahmed Khan, Saleema Amin Kherani, Maqbool Qadir Dec 2016

Erratum To: Neonatal Hyperbilirubinemia In Infants With G6pd C.563c>T Variant, Bushra Moiz, Amna Nasir, Sarosh Ahmed Khan, Saleema Amin Kherani, Maqbool Qadir

Department of Pathology and Laboratory Medicine

No abstract provided.


The Yersinia Pestis Effector Yopm Inhibits Pyrin Inflammasome Activation, Dmitry Ratner, M. Pontus A. Orning, Megan K. Proulx, Donghai Wang, Mikhail A. Gavrilin, Mark D. Wewers, Emad S. Alnemri, Peter F. Johnson, Bettina Lee, Joan Mecsas, Nobuhiko Kayagaki, Jon D. Goguen, Egil Lien Dec 2016

The Yersinia Pestis Effector Yopm Inhibits Pyrin Inflammasome Activation, Dmitry Ratner, M. Pontus A. Orning, Megan K. Proulx, Donghai Wang, Mikhail A. Gavrilin, Mark D. Wewers, Emad S. Alnemri, Peter F. Johnson, Bettina Lee, Joan Mecsas, Nobuhiko Kayagaki, Jon D. Goguen, Egil Lien

Open Access Articles

Type III secretion systems (T3SS) are central virulence factors for many pathogenic Gram-negative bacteria, and secreted T3SS effectors can block key aspects of host cell signaling. To counter this, innate immune responses can also sense some T3SS components to initiate anti-bacterial mechanisms. The Yersinia pestis T3SS is particularly effective and sophisticated in manipulating the production of pro-inflammatory cytokines IL-1beta and IL-18, which are typically processed into their mature forms by active caspase-1 following inflammasome formation. Some effectors, like Y. pestis YopM, may block inflammasome activation. Here we show that YopM prevents Y. pestis induced activation of the Pyrin inflammasome induced ...


Genomic And Transcriptomic Analysis Of Biofilm Formation In Persistent And Transient L. Monocytogenes, Clara Assisi Dec 2016

Genomic And Transcriptomic Analysis Of Biofilm Formation In Persistent And Transient L. Monocytogenes, Clara Assisi

Open Access Theses

The Next Generation Sequencing (NGS) has been popularized and aid in the advancement of many fields of science. The other field of science that is being revolutionized is food science and technology, especially food safety. NGS application in food safety, especially the whole genome sequencing analysis (WGS), has been widely used for tracing back the source of outbreaks. The other application of NGS that is also being developed is the analysis of global transcriptomic or RNA-sequencing (RNA-Seq). In this research, we utilize NGS (Ilumina MiSeq Sequencing platform) to perform sequence comparison and identify single nucleotide polymorphisms (SNPs) and observe the ...


Utilization Of Ferrioxamine Microarrays For The Rapid Detection Of Pathogenic Bacteria, Nigam Bir Arora Dec 2016

Utilization Of Ferrioxamine Microarrays For The Rapid Detection Of Pathogenic Bacteria, Nigam Bir Arora

Open Access Dissertations

Siderophores are low-molecular weight species utilized by bacteria for the sequestration of iron, an essential nutrient. Siderophores and their cognate receptors are considered to be virulence factors, due to their prominent role in pathogenicity. The work presented here focuses on ferrioxamine (FOx) as an “immutable” ligand for pathogen detection. A number of bacterial strains expressing high-affinity FOx receptors were identified by a proteomic BLAST search, and screened against microarrays patterned with FOx conjugates for detection using label-free optical imaging. Aspects such as inkjet printing and surface chemistry, iron-limiting conditions and bacterial selection protocols, and linker conjugate design were addressed and ...


Complex Glycan Utilization Preferences Of Human Gut Bacteria, Yunus Emre Tuncil Dec 2016

Complex Glycan Utilization Preferences Of Human Gut Bacteria, Yunus Emre Tuncil

Open Access Dissertations

Complex glycans, making up dietary fiber, have gained significance in recent years as they are the main energy source for the colonic microbiota which are physiologically important for the host health. Understanding glycan utilization strategies of the members of this community is essential to maximize beneficial health outcomes obtained from them. In order to investigate how the members of our gut microbiota utilize glycans and activate their respective polysaccharide utilization loci (PULs), we performed a series of time-course assays in which two model organisms, Bacteroides thetaiotamicron (Bt) and B. ovatus (Bo), were individually grown in a medium containing carbohydrates utilized ...


Investigating The Effects Of Ph On Alphaviral E3-E2 Glycoprotein Association, Organization, And Cellular Tropism, Jason Michael Sequra Dec 2016

Investigating The Effects Of Ph On Alphaviral E3-E2 Glycoprotein Association, Organization, And Cellular Tropism, Jason Michael Sequra

Open Access Dissertations

In alphaviruses the role of E3 is required in protecting the fusion peptide region of E1 during intracellular transport. Throughout viral processing, the association of E2 and E3 is required for the successful trafficking and incorporation of E1 into the mature virion. This E3-E2 association has been observed to extend to mature virions in the solved structure for the envelope of Semliki Forest virus (SFV) and supported by the solved structure for the entire Venezuelan equine encephalitis virion (VEEV) with exclusive contacts being made between E3-E2. Immunization with monoclonal antibodies against VEEV E3 provided protection for mice challenged by lethal ...


Repurposing Non-Antimicrobial Drugs To Treat Multi-Drug Resistant Bacterial And Fungal Infections, Shankar Thangamani Dec 2016

Repurposing Non-Antimicrobial Drugs To Treat Multi-Drug Resistant Bacterial And Fungal Infections, Shankar Thangamani

Open Access Dissertations

Bacterial and fungal resistance to conventional antimicrobials is a burgeoning global health epidemic that necessitates urgent action. Even more alarming, the development of new antimicrobials to treat these multidrug-resistant pathogens has not kept pace with the rapid emergence of resistance to current antimicrobials. Antimicrobial drug development through the traditional de novo process is a risky venture given the significant financial and time investment required by researchers and limited success rate of translating these compounds to the clinical setting. This has led researchers to mine existing libraries of clinical molecules in order to repurpose old drugs for new applications (as antimicrobials ...


The Elasmobranch-Microbe Relationship: Trimethylamine N-Oxide Synthesis, Urea Hydrolysis, And Microbe-Osmolyte Interactions In The Atlantic Stingray, Dasyatis Sabina, Kaitlin Kelly Doucette Dec 2016

The Elasmobranch-Microbe Relationship: Trimethylamine N-Oxide Synthesis, Urea Hydrolysis, And Microbe-Osmolyte Interactions In The Atlantic Stingray, Dasyatis Sabina, Kaitlin Kelly Doucette

Master's Theses

The elasmobranch osmoregulatory strategy is predicated on the accumulation of nitrogenous compounds, primarily urea and trimethylamine n¬-oxide (TMAO). Despite the abundance of these plasma osmolytes, it is notable that elasmobranchs appear to lack urease and TMA oxidase (Tmase), enzymes that scavenge urea-nitrogen and synthesize TMAO, respectively. However, urease and Tmase are found in many species of bacteria. Therefore, I hypothesized that intestinal bacteria are responsible for urease and Tmase activity in elasmobranchs. Absent dietary nitrogen sources, I evaluated the effects of reduced intestinal microbiota on osmoregulation in Atlantic stingray (Dasyatis sabina) in vivo. D. sabina were given daily broad-spectrum ...


Fecal Bacterial Communities As An Indicator Of Trophic Interactions Among Anuran Larvae, Steven Jacob Everman Dec 2016

Fecal Bacterial Communities As An Indicator Of Trophic Interactions Among Anuran Larvae, Steven Jacob Everman

Master's Theses

Anurans are mass spawners, often with multiple females spawning together, resulting in thousands of tadpoles sharing a habitat. Such large numbers of tadpoles with limited dispersal can lead to intense competition for resources. Inter and intra-specific competition for food could have negative impacts on the growth and survival of smaller tadpoles. Fecal bacterial communities have the potential to be used as indicators of changes in diet making it possible to determine if tadpoles in the wild are eating the same food or not. After feeding on two prepared diets that differed in the percentage of complex carbohydrates, the fecal bacterial ...


Recombinant Listeria Adhesion Protein Expressing Probiotics Protect Against Listeria Monocytogenes Infection In Animal Models, Valerie E. Ryan Dec 2016

Recombinant Listeria Adhesion Protein Expressing Probiotics Protect Against Listeria Monocytogenes Infection In Animal Models, Valerie E. Ryan

Open Access Theses

Listeria monocytogenes (Lm) is a foodborne pathogen, found ubiquitously in nature, and has a high morbidity rate among immunocompromised individuals, the elderly, and especially pregnant women and their fetuses resulting in abortion, stillbirth, and neonatal infection. There are currently no preventative medical interventions against Lm infection. The Listeria adhesion protein (LAP) is present in both pathogenic and non-pathogenic Listeria (i.e., L. innocua) and has shown to interact with host epithelial proteins causing tight junction dysregulation aiding in pathogen attachment and paracellular translocation across the host intestinal epithelium. Our lab has demonstrated that recombinant probiotics, Lactobacillus casei (LbcWT) expressing LAP ...


Antibacterial Activity Of Essential Oil Encapsulated Sodium Iota-Carrageenan Fibers, Carlos D. Carter Dec 2016

Antibacterial Activity Of Essential Oil Encapsulated Sodium Iota-Carrageenan Fibers, Carlos D. Carter

Open Access Theses

Spoilage microorganisms cause food waste and loss of quality. While the foodborne pathogen outbreaks lead to thousands of hospitalizations and deaths. Essential oils (EOs), plant extracts, possess the required antimicrobial activities and thus their usage stands out as a feasible approach for controlling the undesirable bacterial growth in food systems. However, EOs are highly volatile and lose their activity upon exposure to environmental conditions. In this regard, their encapsulation in Generally Recognized As Safe (GRAS) matrices such as food grade polysaccharides especially iota-carrageenan could be one of the viable alternatives. Iota-carrageenan, sulfated polysaccharide from marine algae, is being used in ...


Inactivation Of Chromosomal Genes Of The Choline Bacterial Microcompartment Through Transformation Of Escherichia Coli 536, Tiffany Harris Dec 2016

Inactivation Of Chromosomal Genes Of The Choline Bacterial Microcompartment Through Transformation Of Escherichia Coli 536, Tiffany Harris

Honors Projects and Posters

Bacterial microcompartments (BMCs) are proteinaceous organelle structures inside a bacterium that allow enzymatic activity to occur within a controlled space. Several different types of BMCs have been identified including microcompartments that facilitate the breakdown of choline into products that can be used by the cell. While research has revealed general information about the protein shell of BMCs, not much is known about the specific genes that are involved in the choline microcompartment. This project was conducted to determine the effects inactivation of genes implicated in the choline microcompartment would have on Escherichia coli 536 and its ability to breakdown choline ...


Oral Microbial Burden Of Periodontal Pathogens Among Orthodontic Patients, David Jolley Dec 2016

Oral Microbial Burden Of Periodontal Pathogens Among Orthodontic Patients, David Jolley

UNLV Theses, Dissertations, Professional Papers, and Capstones

Objectives

Many research studies involving orthodontic patients have a natural inclination to focus on changes in levels of cariogenic pathogens after bracket placement, and very few studies examine the role of changes of periodontal pathogens – particularly among adult patients. Interestingly, recent evidence suggests that increased levels of a specific periodontal pathogen, Fusobacterium nucleatum, may elevate risk for development of colon cancer in adults through direct pathways. Based upon this new evidence, the objective of the current study was to screen saliva samples taken from orthodontic patients to determine the prevalence of periodontal pathogens, including F. Nucleatum, T. denticola, and P ...


Development Of The K-State (Competence) And Mutagenesis In Stressed Bacillus Subtillis Cells, Amanda Kidman Dec 2016

Development Of The K-State (Competence) And Mutagenesis In Stressed Bacillus Subtillis Cells, Amanda Kidman

UNLV Theses, Dissertations, Professional Papers, and Capstones

Mutagenesis is central to the evolutionary process. We currently view evolution as a gradual process affecting all cells within a population. However, my project studied an underestimated part of the evolutionary process: mutations generated during stationary phase (caused by nutritional stress or growth arrest) within a subpopulation of cells. I used Bacillus subtilis, a bacterial model for cell growth and differentiation. Stationary-phase cultures of B. subtilis differentiate subpopulations that exhibit different survival strategies including competence, secondary metabolite production, biofilm formation, cannibalism, and endospore formation. The development of competence permits cells to uptake exogenous DNA and incorporate it into their genome ...


Exploring Enrichment Cultures Of Denitrifying Microorganisms From El Yunque National Forest, Samiha Ahsan, Jenny Onley, Frank Loeffler Dec 2016

Exploring Enrichment Cultures Of Denitrifying Microorganisms From El Yunque National Forest, Samiha Ahsan, Jenny Onley, Frank Loeffler

Chancellor’s Honors Program Projects

No abstract provided.


Sodium Polyphosphate And Polyethylenimine Enhance The Antimicrobial Activities Of Plant Essential Oils, Heidi A. Wright, Byron F. Brehm-Stecher Dec 2016

Sodium Polyphosphate And Polyethylenimine Enhance The Antimicrobial Activities Of Plant Essential Oils, Heidi A. Wright, Byron F. Brehm-Stecher

Food Science and Human Nutrition Publications

Plant extracts have been used for millennia for treatment of disease, with much recent interest focusing on the antimicrobial activities of plant essential oils (EOs). Although EOs are active against common microbial pathogens, their effective use as topical, environmental, or food antimicrobials will require EO-based formulations with enhanced antimicrobial activities. In this study, two polyionic compounds, sodium polyphosphate (polyP, a polyanion) and polyethylenimine (PEI, a polycation), were evaluated for their abilities to enhance the antimicrobial activities of six EOs against the human pathogens Escherichia coli O157:H7, Salmonella enterica subsp. enterica ser. Minnesota, Pseudomonas aeruginosa, Listeria monocytogenes, Staphylococcus aureus, and ...


The Role Of Streptococcus Gallolyticus Subspecies Gallolyticus In Colon Cancer Development, Jennifer L. Herold Dec 2016

The Role Of Streptococcus Gallolyticus Subspecies Gallolyticus In Colon Cancer Development, Jennifer L. Herold

UT GSBS Dissertations and Theses (Open Access)

Colorectal cancer (CRC) is the third most common cancer in men and women and is also the third most common cause of cancer death. A large body of evidence points towards the possibility that bacteria can have a significant impact on the development of cancer. It has been suggested that Streptococcus gallolyticus subsp. gallolyticus, a group D streptococci, may play a role in the development of CRC. Sg, formerly S. bovis biotype I, has been shown to be highly associated with CRC. In observing patients with either Sg bacteremia or endocarditis it was found that 25-80% of patients with Sg ...


A Portable And Automatic Biosensing Instrument For Detection Of Foodborne Pathogenic Bacteria In Food Samples, Zhuo Zhao Dec 2016

A Portable And Automatic Biosensing Instrument For Detection Of Foodborne Pathogenic Bacteria In Food Samples, Zhuo Zhao

Theses and Dissertations

Foodborne diseases are a growing public health problem. In recent years, many rapid detection methods have been reported, but most of them are still in lab research and not practical for use in the field. In this study, a portable and automatic biosensing instrument was designed and constructed for separation and detection of target pathogens in food samples using nanobead-based magnetic separation and quantum dots (QDs)-labeled fluorescence measurement. The instrument consisted of a laptop with LabVIEW software, a data acquisition card (DAQ), a fluorescent detector, micro-pumps, stepper motors, and 3D printed tube holders. First, a sample in a syringe ...