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Molecular Biology Of A Surface-Exposed Protein Family Of Bartonella Bacilliformis, Hannah Fay 2017 University of Montana

Molecular Biology Of A Surface-Exposed Protein Family Of Bartonella Bacilliformis, Hannah Fay

Undergraduate Theses and Professional Papers

Bartonella bacilliformis is a gram negative alpha-proteobacterium native to the Andes of South America. Bartonella causes Carrion’s disease, a potentially life threatening disease transmitted by the sand fly. It has a mortality rate of 88% when untreated and 10% when treated. Diagnostics and control measures for the disease are underdeveloped and no vaccine is available. Recent outbreaks indicate that the range of the pathogen is increasing with nearly 1.7 million people in western South America at risk. Little is known about the epidemiology and pathogenesis of B. bacilliformis. Recent research done by UC San Diego found a paralogous ...


Xpert Mtb/Rif Assay Shows Faster Clearance Of Mycobacterium Tuberculosis Dna With Higher Levels Of Rifapentine Exposure., A Jayakumar, R M Savic, C K Everett, Debra Benator, D Alland, C M Heilig, M Weiner, S O Friedrich, N A Martinson, A Kerrigan, C Zamudio, S V Goldberg, W C Whitworth, J L Davis, P Nahid 2016 George Washington University

Xpert Mtb/Rif Assay Shows Faster Clearance Of Mycobacterium Tuberculosis Dna With Higher Levels Of Rifapentine Exposure., A Jayakumar, R M Savic, C K Everett, Debra Benator, D Alland, C M Heilig, M Weiner, S O Friedrich, N A Martinson, A Kerrigan, C Zamudio, S V Goldberg, W C Whitworth, J L Davis, P Nahid

Medicine Faculty Publications

The Xpert MTB/RIF assay is both sensitive and specific as a diagnostic test. Xpert also reports quantitative output in cycle threshold (CT) values, which may provide a dynamic measure of sputum bacillary burden when used longitudinally. We evaluated the relationship between Xpert CT trajectory and drug exposure during tuberculosis (TB) treatment to assess the potential utility of Xpert CT for treatment monitoring. We obtained serial sputum samples from patients with smear-positive pulmonary TB who were consecutively enrolled at 10 international clinical trial sites participating in study 29X, a CDC-sponsored Tuberculosis Trials Consortium study evaluating the tolerability, safety, and antimicrobial ...


Characterization Of Antimicrobial Activity Of Culturable Bacteria Isolated From Krubera-Voronja Cave, Aiste Klusaite, Vida Vickackaite, Birute Vaitkeviciene, Rasa Karnickaite, Dominykas Bukelskis, Ieva Kieraite-Aleksandrova, Nomeda Kuisiene 2016 Vilnius University

Characterization Of Antimicrobial Activity Of Culturable Bacteria Isolated From Krubera-Voronja Cave, Aiste Klusaite, Vida Vickackaite, Birute Vaitkeviciene, Rasa Karnickaite, Dominykas Bukelskis, Ieva Kieraite-Aleksandrova, Nomeda Kuisiene

International Journal of Speleology

In the present study we aimed to perform the first analysis of antimicrobial activity of bacteria isolated from Krubera-Voronja Cave, with the main focus on their activity against Grampositive bacteria, including Gram-positive pathogens. Using five different media, in total 874 heterotrophic cultures were isolated from water and sediment samples collected in Krubera-Voronja Cave at a depth from 220 m to 1640 m. 14.0% of all isolates demonstrated antibacterial activity against Gram-positive and Gram-negative test microorganisms. Our results show that this percentage was not uniform; it increased with the sampling depth and was the highest in the lower part of ...


Presence Of A Prophage Determines Temperature-Dependent Capsule Production In Streptococcus Pyogenes., Leslie Brown, Jeong-Ho Kim, Kyu Hong Cho 2016 George Washington University

Presence Of A Prophage Determines Temperature-Dependent Capsule Production In Streptococcus Pyogenes., Leslie Brown, Jeong-Ho Kim, Kyu Hong Cho

Biochemistry and Molecular Medicine Faculty Publications

A hyaluronic acid capsule is a major virulence factor in the pathogenesis of Streptococcus pyogenes. It acts as an anti-phagocytic agent and adhesin to keratinocytes. The expression of the capsule is primarily regulated at the transcriptional level by the two-component regulatory system CovRS, in which CovR acts as a transcriptional repressor. The covRS genes are frequently mutated in many invasive strains, and a subset of the invasive CovRS mutants does not produce a detectable level of the capsule at 37 °C, but produces a significant amount of the capsule at sub-body temperatures. Here, we report that a prophage has a ...


N-Methylation Of A Bactericidal Compound As A Resistance Mechanism In Mycobacterium Tuberculosis, Kenan C. Murphy, Carl F. Nathan 2016 University of Massachusetts Medical School

N-Methylation Of A Bactericidal Compound As A Resistance Mechanism In Mycobacterium Tuberculosis, Kenan C. Murphy, Carl F. Nathan

Open Access Articles

The rising incidence of antimicrobial resistance (AMR) makes it imperative to understand the underlying mechanisms. Mycobacterium tuberculosis (Mtb) is the single leading cause of death from a bacterial pathogen and estimated to be the leading cause of death from AMR. A pyrido-benzimidazole, 14, was reported to have potent bactericidal activity against Mtb. Here, we isolated multiple Mtb clones resistant to 14. Each had mutations in the putative DNA-binding and dimerization domains of rv2887, a gene encoding a transcriptional repressor of the MarR family. The mutations in Rv2887 led to markedly increased expression of rv0560c. We characterized Rv0560c as an S-adenosyl-L-methionine-dependent ...


Sequencing And Comparative Analysis Of De Novo Genome Assemblies Of Streptomyces Aureofaciens Atcc 10762, Julien S. Gradnigo 2016 University of Nebraska - Lincoln

Sequencing And Comparative Analysis Of De Novo Genome Assemblies Of Streptomyces Aureofaciens Atcc 10762, Julien S. Gradnigo

Dissertations and Theses in Biological Sciences

Streptomyces aureofaciens is a Gram-positive Actinomycete used for commercial antibiotic production. Although it has been the subject of many biochemical studies, no public genome resource was available prior to this project. To address this need, the genome of S. aureofaciens ATCC 10762 was sequenced using a combination of sequencing platforms (Illumina and 454-shotgun). Multiple de novo assembly methods (SGA, IDBA, Trinity, SOAPdenovo2, MIRA, Velvet and SPAdes) as well as combinations of these methods were assessed to determine which provided the most robust assembly. Combination strategies led to a consistent overestimation of the total genome size. Empirical data from targeted PCR ...


Separate F-Type Plasmids Have Shaped The Evolution Of The H30 Subclone Of Escherichia Coli Sequence Type 131., Timothy J Johnson, Jessica L Danzeisen, Bonnie Youmans, Kyle Case, Katharine Llop, Jeannette Munoz-Aguayo, Cristian Flores-Figueroa, Maliha Aziz, Nicole Stoesser, Evgeni Sokurenko, Lance B. Price, James R Johnson 2016 George Washington University

Separate F-Type Plasmids Have Shaped The Evolution Of The H30 Subclone Of Escherichia Coli Sequence Type 131., Timothy J Johnson, Jessica L Danzeisen, Bonnie Youmans, Kyle Case, Katharine Llop, Jeannette Munoz-Aguayo, Cristian Flores-Figueroa, Maliha Aziz, Nicole Stoesser, Evgeni Sokurenko, Lance B. Price, James R Johnson

Environmental and Occupational Health Faculty Publications

The extraintestinal pathogenic Escherichia coli (ExPEC) H30 subclone of sequence type 131 (ST131-H30) has emerged abruptly as a dominant lineage of ExPEC responsible for human disease. The ST131-H30 lineage has been well described phylogenetically, yet its plasmid complement is not fully understood. Here, single-molecule, real-time sequencing was used to generate the complete plasmid sequences of ST131-H30 isolates and those belonging to other ST131 clades. Comparative analyses revealed separate F-type plasmids that have shaped the evolution of the main fluoroquinolone-resistant ST131-H30 clades. Specifically, an F1:A2:B20 plasmid is strongly associated with ...


Memory Cd8+ T Cell Function During Mycobacterium Tuberculosis Infection: A Dissertation, Stephen M. Carpenter 2016 University of Massachusetts Medical School

Memory Cd8+ T Cell Function During Mycobacterium Tuberculosis Infection: A Dissertation, Stephen M. Carpenter

GSBS Dissertations and Theses

T cell vaccines against Mycobacterium tuberculosis (Mtb) and other pathogens are based on the principle that memory T cells rapidly generate effector responses upon challenge, leading to pathogen clearance. Despite eliciting a robust memory CD8+ T cell response to the immunodominant Mtb antigen TB10.4 (EsxH), we find the increased frequency of TB10.4-specific CD8+ T cells conferred by vaccination to be short-lived after Mtb challenge. To compare memory and naïve CD8+ T cell function during their response to Mtb, we track their expansions using TB10.4-specific retrogenic CD8+ T cells. We find that the primary (naïve) response outnumbers the ...


Implication Of Biological And Synthetic Nanoparticles In Evolution And Development Of Antibiotic Resistance Relevant For Aquaculture, Petter Langlete 2016 University of Oslo

Implication Of Biological And Synthetic Nanoparticles In Evolution And Development Of Antibiotic Resistance Relevant For Aquaculture, Petter Langlete

2nd International Conference of Fish & Shellfish Immunology

No abstract provided.


Synthesis And Biological Activity Of Novel Quorum Sensing Compounds, Joseph Nicholas Capilato 2016 Rowan University

Synthesis And Biological Activity Of Novel Quorum Sensing Compounds, Joseph Nicholas Capilato

Theses and Dissertations

Bacteria communicate with chemical signals in a process known as quorum sensing. This population density-dependent process involves the bacterial production, release and detection of structurally specific small molecules and enables the bacterial pathogen to regulate its virulence on a population-wide level. Using a variety of chemical and biological techniques, I have studied various quorum sensing systems in several bacteria, including Vibrio cholera and Pseudomonas aeruginosa. A key principle of this research involves the design, synthesis and testing of novel compounds for their biological activity. These molecules are typically based off of an initial lead target, which is often identified from ...


Type I Interferon Induction By Neisseria Gonorrhoeae: Dual Requirement Of Cyclic Gmp-Amp Synthase And Toll-Like Receptor 4, Warrison A. Andrade, Sarika Agarwal, Shunyan Mo, Scott A. Shaffer, Joseph P. Dillard, Tobias Schmidt, Veit Hornung, Katherine A. Fitzgerald, Evelyn A. Kurt-Jones, Douglas T. Golenbock 2016 University of Massachusetts Medical School

Type I Interferon Induction By Neisseria Gonorrhoeae: Dual Requirement Of Cyclic Gmp-Amp Synthase And Toll-Like Receptor 4, Warrison A. Andrade, Sarika Agarwal, Shunyan Mo, Scott A. Shaffer, Joseph P. Dillard, Tobias Schmidt, Veit Hornung, Katherine A. Fitzgerald, Evelyn A. Kurt-Jones, Douglas T. Golenbock

Open Access Articles

The innate immune system is the first line of defense against Neisseria gonorrhoeae (GC). Exposure of cells to GC lipooligosaccharides induces a strong immune response, leading to type I interferon (IFN) production via TLR4/MD-2. In addition to living freely in the extracellular space, GC can invade the cytoplasm to evade detection and elimination. Double-stranded DNA introduced into the cytosol binds and activates the enzyme cyclic-GMP-AMP synthase (cGAS), which produces 2'3'-cGAMP and triggers STING/TBK-1/IRF3 activation, resulting in type I IFN expression. Here, we reveal a cytosolic response to GC DNA that also contributes to type I ...


Biosynthesis And Roles Of Virulence Conferring Cell Wall Associated Dimycocerosate Esters In Mycobacterium Marinum, Poornima Mohandas 2016 Graduate Center, City University of New York

Biosynthesis And Roles Of Virulence Conferring Cell Wall Associated Dimycocerosate Esters In Mycobacterium Marinum, Poornima Mohandas

All Graduate Works by Year: Dissertations, Theses, and Capstone Projects

Mycobacterial species include a variety of obligate and opportunistic pathogens that cause several important diseases affecting mankind such as tuberculosis and leprosy. The most unique feature of these bacteria is their intricate cell wall that poses a permeability barrier to antibiotics and contributes to their pathogenicity and persistence within the host. The cell wall hosts several complex lipids such as dimycocerosate esters (DIMs), which are found in many clinically relevant pathogenic species of mycobacteria. DIMs have been implicated in the virulence of mycobacteria and play a major role in helping the bacteria evade host immune responses. It is therefore crucial ...


Is Aerosalization A Problem With Carbapenem-Resistant Acinetobacter Baumannii In Thailand Hospital?, Anucha Apisarnthanarak, Ploenpit Tantajina, Pornpimol Laovachirasuwan, David J. Weber, Nalini Singh 2016 George Washington University

Is Aerosalization A Problem With Carbapenem-Resistant Acinetobacter Baumannii In Thailand Hospital?, Anucha Apisarnthanarak, Ploenpit Tantajina, Pornpimol Laovachirasuwan, David J. Weber, Nalini Singh

Pediatrics Faculty Publications

We evaluated the presence of air contamination with carbapenem-resistant Acinetobacter baumannii (CRAB) in medical units where patients with CRAB pneumonia were hospitalized, and in Obstetrics and Gynecology units with open-air ventilation in-patient settings. There was no evidence of CRAB contamination in either of the units.


Household Clustering Of Escherichia Coli Sequence Type 131 Clinical And Fecal Isolates According To Whole Genome Sequence Analysis, James R. Johnson, Gregg Davis, Connie Clabots, Brian D. Johnston, Stephen Porter, Lance B. Price, +10 additional authors 2016 George Washington University

Household Clustering Of Escherichia Coli Sequence Type 131 Clinical And Fecal Isolates According To Whole Genome Sequence Analysis, James R. Johnson, Gregg Davis, Connie Clabots, Brian D. Johnston, Stephen Porter, Lance B. Price, +10 Additional Authors

Environmental and Occupational Health Faculty Publications

Background. Within-household sharing of strains from the resistance-associated H30R1 and H30Rx subclones of Escherichia coli sequence type 131 (ST131) has been inferred based on conventional typing data, but has been assessed minimally using whole genome sequence (WGS) analysis.

Methods. Thirty-three clinical and fecal isolates of ST131-H30R1 and ST131-H30Rx, from 20 humans and pets in six households, underwent WGS analysis for comparison with 52 published ST131 genomes. Phylogenetic relationships were inferred using a bootstrapped maximum likelihood tree based on core genome sequence polymorphisms. Accessory traits were compared between phylogenetically similar isolates.

Results. In the WGS-based ...


Mathematical Models Of Biofilm For Antimicrobial Persistence, Jia Zhao 2016 University of North Carolina at Chapel Hill

Mathematical Models Of Biofilm For Antimicrobial Persistence, Jia Zhao

Biology and Medicine Through Mathematics Conference

No abstract provided.


Regulation Of Cid-Mediated Cell Death In Staphylococcus Aureus, Ian H. Windham 2016 University of Nebraska Medical Center

Regulation Of Cid-Mediated Cell Death In Staphylococcus Aureus, Ian H. Windham

Theses & Dissertations

The death and lysis of a subpopulation of cells in Staphylococcus aureus biofilms is thought to benefit the surviving population by releasing extracellular DNA, a critical component of the biofilm extracellular matrix. Although the means by which S. aureus controls cell death and lysis is not completely understood, studies implicate the role of the cidABC, alsSD and lrgAB operons in this process. This dissertation has focused on the regulation of cidABC and alsSD expression, which is mediated, primarily, by the LysR-Type Transcriptional Regulator (LTTR) known as CidR. To better define the role of CidR in regulating cidABC and alsSD transcription ...


Identification Of Host Factors Required For Yersinia Pestis Macrophage Intracellular Survival And Their Impact On Vacuole Maturation, Acidification And Trafficking., Michael Graylin Connor 2016 University of Louisville

Identification Of Host Factors Required For Yersinia Pestis Macrophage Intracellular Survival And Their Impact On Vacuole Maturation, Acidification And Trafficking., Michael Graylin Connor

Electronic Theses and Dissertations

Y. pestis is a facultative intracellular pathogen and the causative agent of plague. This bacterium, while most noted or the Black Death during the European 14th century, is not a historic pathogen but a re-emerging pandemic with both domestic and global impact. Y. pestis is capable of colonizing the macrophage, and actively subverts phagolysosome maturation to establish a replicative niche known as the Yersinia containing vacuole (YCV). The exploited host factors required to support the YCV are unknown. Here we identified a comprehensive list of host factors required for Y. pestis survival through a genome-wide RNAi high-throughput screen. We ...


Characterization Of The Role Of The Burkholderia Pseudomallei Type 3 Secretion System Using In Vivo Imaging., Maria Gabriela Gutierrez 2016 University of Louisville

Characterization Of The Role Of The Burkholderia Pseudomallei Type 3 Secretion System Using In Vivo Imaging., Maria Gabriela Gutierrez

Electronic Theses and Dissertations

Melioidosis is a fatal infectious disease caused by the Tier 1 Select Agent Burkholderia pseudomallei. Hallmarks of melioidosis include pneumonic disease and prominent septicaemic spread. Both forms of disease are contingent upon the bacterium’s intracellular life cycle and particularly on its ability to escape from host cell phagosomes. Upon encountering a host cell, B. pseudomallei is internalized into membrane-bound vacuoles from which the bacterium must rapidly escape to the cytoplasm in order to replicate and promote its survival. In the host cytoplasm, B. pseudomallei is capable of polymerizing actin for intracellular and intercellular motility and spread, lysing the host ...


Modulation Of Cell Death Signaling And Cell Proliferation By The Interaction Of Homoserine Lactones And Paraoxonase 2., Aaron Mackallan Neely 2016 University of Louisville

Modulation Of Cell Death Signaling And Cell Proliferation By The Interaction Of Homoserine Lactones And Paraoxonase 2., Aaron Mackallan Neely

Electronic Theses and Dissertations

Pseudomonas aeruginosa produces N-(3-oxododecanoyl)-homoserine lactone (C12) as a quorum-sensing molecule that functions to facilitate bacteria-bacteria communication. C12 has also been reported to affect many aspects of human host cell physiology, including evoking cell death in various types of cells. However, the signaling pathway(s) leading to C12-triggerred cell death remains unclear. To clarify cell death signaling induced by C12, we examined mouse embryonic fibroblasts (MEFs) deficient in one or more caspases. Our data indicate that, unlike most apoptotic inducers, C12 evokes a novel form of apoptosis in cells, probably through the direct induction of mitochondrial membrane permeabilization. Previous ...


Contribution Of Probiotics Streptococcus Salivarius Strains K12 And M18 To Oral Health In Humans: A Review, Turner A. Stowik 2016 University of Connecticut

Contribution Of Probiotics Streptococcus Salivarius Strains K12 And M18 To Oral Health In Humans: A Review, Turner A. Stowik

Honors Scholar Theses

The overgrowth and disequilibrium of pathogenic microorganism species both native and non-native to the oral cavity can manifest into a variety of different oral diseases, pathologies, and afflictions in humans, including dental caries, gingivitis, pharyngitis, halitosis, and oral candidiasis. Two bacterial strains with clinically-significant probiotic applications in curtailing the pathogenic bacterial growth involved in these conditions are Streptococcus salivarius strain K12 and Streptococcus salivarius strain M18. To summarize the most up-to-date in vitro, in vivo, and clinical research findings, administration of these S. salivarius strains typically in the form of probiotic lozenges results in colonization, reduction in inflammatory measures, and ...


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