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The Thiol Specific Antioxidant (Tsa1) Gene Is Required For Survival In Macrophages And Oxidative Stress Resistance In Histoplasma Capsulatum, Lauren Kennedy

Master's Theses

Histoplasma capsulatum(Hc) is a pathogenic fungus that causes one of the most common invasive fungal respiratory diseases, Histoplasmosis. Histoplasmaundergoes a dimorphic shift from mold to yeast which is crucial to pathogenesis of the organism.

The thiol specific antioxidant gene, Tsa1,is strongly upregulated in the yeast (pathogenic) morphotype. This data led to the hypothesis that this gene plays a role in protecting Hcfrom host mediated oxidative attack. To characterize Tsa1 function, a knockdown strain (tsa1-RNAi) was created by RNAi gene silencing. Expression of Tsa1in the tsa1-RNAistrain was reduced to 10% that …

The Effect Of Historic Shipwrecks On Sediment Microbiomes In The Northern Gulf Of Mexico, Melissa Brock

Master's Theses

Microorganisms are ubiquitously distributed across all aquatic habitats, but it is the environmental conditions of a habitat that determine which microorganisms can thrive in terms of abundance or metabolic activity. Habitats that experience consistent physical and chemical environmental conditions repeatedly favor specific taxonomic groups which may result in a microbial assemblage that is commonly associated with that habitat (i.e., a core microbiome). Core microbiomes have been identified for a variety of natural marine habitats including methane seeps, wood falls, octocoral, and deep-sea sediments. However, it was unknown if the presence of man-made structures on the seafloor, including historic shipwrecks, also …

The Evolutionary Diversity And Biological Function Of Phenazine Metabolite Biosynthesis In Burkholderia Spp, Samuel Hendry

Master's Theses

Burkholderia encompass a group of ubiquitous Gram-negative bacteria that include numerous saprophytes, as well as several species that cause infections in animals, immunocompromised patients, and plants. Some species of Burkholderia produce colored redox-active secondary metabolites called phenazines (Phz). In the model opportunistic pathogen Pseudomonas aeruginosa, phenazines strongly contribute to the competitiveness, formation of biofilms, and virulence in multiple models of infection. Similar depth of knowledge on the diversity, biosynthesis, and biological functions of phenazines in Burkholderiais missing. This project aimed to bridge this gap in knowledge by focusing on phenazine pathways of B. lata and closely related …