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Microbiology

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Washington University in St. Louis

2020

Articles 1 - 8 of 8

Full-Text Articles in Life Sciences

Structural Insights Into Host-Pathogen Interactions Of Alphaviruses, Katherine Basore Dec 2020

Structural Insights Into Host-Pathogen Interactions Of Alphaviruses, Katherine Basore

Arts & Sciences Electronic Theses and Dissertations

Alphaviruses are arthropod-borne, single-stranded positive-sense RNA viruses of the Togaviridae family that infect various vertebrates worldwide in tropical and temperate areas, causing emerging and reemerging diseases in humans. Mature virions are 70 nm in diameter and contain a ~11-kilobase genome encapsidated within a nucleocapsid core, a host-derived lipid bilayer, and an envelope comprised of heterodimers of the glycoproteins E1 and E2 arranged into trimeric spikes with T=4 icosahedral symmetry. Alphaviruses are categorized into two groups based on their clinical symptoms: the arthritogenic alphaviruses, such as chikungunya (CHIKV), Mayaro (MAYV), Ross River (RRV), Semliki Forest (SFV), and O’nyong-nyong (ONNV) viruses, which …

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Engineering Natural Competence Into The Fast-Growing Cyanobacterium Synechococcus Elongatus Utex 2973, Kristen Elizabeth Wendt Aug 2020

Engineering Natural Competence Into The Fast-Growing Cyanobacterium Synechococcus Elongatus Utex 2973, Kristen Elizabeth Wendt

Arts & Sciences Electronic Theses and Dissertations

Synechococcus elongatus UTEX 2973 is the fastest growing cyanobacterium discovered to date. Using water, carbon dioxide, and light alone, this organism can double in 1.5 hours under optimal conditions. The accelerated doubling exhibited by Synechococcus 2973 makes it a prime candidate to serve as a model photoautotrophic system. However, Synechococcus 2973 lacks one highly desirable feature: it cannot undergo natural transformation. This thesis seeks to engineer this capacity into this fast-growing system in order to create an organism that is both fast growing and naturally competent. Synechococcus 2973 is a unique platform because it is >99% genetically identical to another …

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Genomic Analysis Of Diverse Bacterial Pathogens, Robert Potter Aug 2020

Genomic Analysis Of Diverse Bacterial Pathogens, Robert Potter

Arts & Sciences Electronic Theses and Dissertations

Bacterial pathogens have been a historical scourge for the entirety of human existence but have been significantly thwarted since the 20th century due to the development of antibiotics. However, owing to the large selection pressure of antibiotics on bacterial populations, phenotypic antibiotic resistance from the development of vertically transmitted mutations and horizontally acquired antibiotic resistance genes (ARGs) is increasing. The sum has produced multidrug resistant organisms (MDROs) which have extremely limited treatment options. Epidemiological studies have determined that carbapenem resistant Enterobacteriaceae (CRE), Acinetobacter baumannii, and vancomycin resistant Enterococcus (VRE) are some of the most problematic MDRO infections. The advent of …

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Lymphatic Filariasis: Host And Parasite Factors And The Pathogenesis Of Systemic Adverse Events Following Treatment, Britt Juul Andersen May 2020

Lymphatic Filariasis: Host And Parasite Factors And The Pathogenesis Of Systemic Adverse Events Following Treatment, Britt Juul Andersen

Arts & Sciences Electronic Theses and Dissertations

Lymphatic filariasis (LF) is a neglected tropical disease caused by the nematode parasites Wuchereria bancrofti, Brugia malayi and B. timori. The primary tool used by the Global Program to Eliminate LF is mass drug administration (MDA), and some 500 million people take the medications each year. Mild to moderate adverse events (AEs) are common after LF treatment, and these pose a major challenge for the LF elimination program. To better understand the pathogenesis of AEs, we studied patients from LF treatment trials in Côte d’Ivoire and Papua New Guinea, where plasma and leucocytes were collected pre and post-treatment and subjects …

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Mitochondrial Morphology, Oxidative Stress Resistance, And Pathogenesis In Cryptococcus Neoformans, Andrew Lee Chang May 2020

Mitochondrial Morphology, Oxidative Stress Resistance, And Pathogenesis In Cryptococcus Neoformans, Andrew Lee Chang

Arts & Sciences Electronic Theses and Dissertations

Cryptococcus neoformans is an important pathogen that annually kills 200,000 people worldwide. It survives in the environment as a yeast or spore and can also proliferate within host macrophages after being inhaled into the lungs. In conditions of immunocompromise, cryptococcal cells can escape from the lungs to the brain, where they cause a deadly meningoencephalitis that is both difficult and expensive to treat. Cryptococcal adaptation to the harsh lung environment is a critical first step in its pathogenesis, and consequently a compelling topic of study. This adaptation is mediated by a complex transcriptional program that integrates cellular responses to environmental …

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Cognitive Recovery In The Post-Infectious Cns, Charise Joy Garber May 2020

Cognitive Recovery In The Post-Infectious Cns, Charise Joy Garber

Arts & Sciences Electronic Theses and Dissertations

Neuroinflammation plays a pivotal role in a variety of diseases of the CNS associated with cognitive impairment, including Alzheimerճ Disease, Parkinsonճ Disease with dementia, Multiple Sclerosis, anti-NMDA receptor encephalitis, and West Nile Virus Neuroinvasive disease (WNND). Despite strong evidence that infiltration of peripheral immune cells and activation of resident microglia and astrocytes occurs in these various diseases, very little is known about how this altered immune environment may influence normal cognitive function. Given that communication between the nervous and immune system is essential for normal cognitive function, the central motivation of my thesis work is to understand the mechanisms by …

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Molecular Insights Into Microbial Adhesion, Roger Davies Klein May 2020

Molecular Insights Into Microbial Adhesion, Roger Davies Klein

Arts & Sciences Electronic Theses and Dissertations

Antibiotic-resistant bacterial infections are a serious and immediate threat to global public health. In the United States alone, over 2 million individuals develop antibiotic-resistant infections annually, resulting in 23,000 deaths and $20 billion in excess health care costs. Virulence factors that allow bacteria to invade and persist within the host are promising targets for novel antimicrobial agents that could be used to curb the spread of antibiotic resistance. Development of therapeutics that can selectively eliminate pathogenic bacteria while sparing the beneficial host microbiota requires a detailed molecular understanding of critical virulence factors that facilitate interactions between pathogens and their environments. …

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Development Of An In Vitro Culture System For Cryptosporidium Parvum, Georgia Wilke May 2020

Development Of An In Vitro Culture System For Cryptosporidium Parvum, Georgia Wilke

Arts & Sciences Electronic Theses and Dissertations

Cryptosporidium is a genus of protozoan parasites that causes diarrheal disease in humans and other animals. There are two major species that cause disease in humans: C. parvum, which infects both humans and animals, and C. hominis, which primarily infects humans. A recent study investigating the etiologies of pediatric diarrheal illness in Africa and South Asia found that Cryptosporidium is the 2nd most prevalent cause of diarrhea in infants and may be a contributing factor to chronic malnutrition. This discovery has led to renewed interest in studying this parasite and a reexamination of the barriers to studying Cryptosporidium. The main …

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