Life Sciences Commons^™

Mechanisms Of Stress Survival In Gram Positive Bacterial Pathogens, Asia Poudel

Chemistry & Biochemistry Theses & Dissertations

Anaerobic Gram-positive bacteria are not a well-characterized group but include many human pathogens that are resilient against stresses caused by the human immune system or by antibiotic treatment. This dissertation investigated the survival mechanisms of two clinically relevant Gram-positive organisms, Clostridioides difficile and Cutibacterium acnes under extracellular stresses. The response of the opportunistic skin pathogen Cutibacterium acnes to nanosecond electric pulses is characterized and found that growth in a biofilm, which usually protects bacteria from stress, renders this species more killable by this treatment. In addition, the stringent response (SR), a conserved bacterial stress survival mechanism, is studied in the …

Evaluation Of Horizontal Gene Transfer Between Genetically Engineered Cyanobacteria And Gram-Negative Bacteria, Andriana Chrysovalanti Zourou

Chemistry & Biochemistry Theses & Dissertations

As the world population is increasing and societies become more technology driven, there is an imperative to develop ‘green energy’ sources to protect our planet. Cyanobacteria that have been genetically engineered to produce organic compounds that may be burnt as fuels show great potential, as they are an environmentally friendly and self-renewable, net carbon-neutral option. However, there are potential risks in the development and use of genetically modified organisms (GMOs). We need to understand in advance the risks that GMOs may pose to our environment and to animal and human health. This will enable experimental procedures, containment strategies and policies …

Biophysical Characterization Of The Par-4 Tumor Suppressor: Evidence Of Structure Outside The Coiled Coil Domain And Interactions With Platinum Chemotherapeutics, Andrea Megan Clark

Chemistry & Biochemistry Theses & Dissertations

Prostate apoptosis response-4 (Par-4) is an apoptosis-inducing tumor suppressor protein. Full-length Par-4 has previously been shown to be a predominantly intrinsically disordered protein (IDP) under neutral conditions, with significant regular secondary structure evident only within the C-terminal coiled coil domain. However, IDPs can gain ordered structure through the process of induced folding, which often occurs under non-neutral conditions. Previous work has shown that the Par-4 leucine zipper, which is a subset of the C-terminal coiled coil domain, is disordered under neutral conditions, but forms a dimeric coiled coil at acidic pH. Increase in ionic strength was also shown to increase …

A Test Of Rad Capture Sequencing On Ethanol-Preserved Centennial And Contemporary Specimens Of Philippine Fishes, Madeleine I. Kenton

Biological Sciences Theses & Dissertations

Understanding the relationship between ecological characteristics and genetic change in natural populations in different time scales can reveal how anthropogenic stressors affect natural populations and can improve the success of conservation strategies. The purpose of the Philippines Partnerships for International Research and Education (PIRE) project is to examine levels of genetic change between historical fish samples collected by the USS Albatross expedition in the early 1900s in the Philippines and contemporary populations collected at the same localities. This study tests genetic protocols to process historical and contemporary DNA for simultaneous comparison. Two DNA library preparation methods, single digest RADseq (“un-baited” …

Anaplasma Phagocytophilum Modulates Mammalian And Arthropod Signaling For Its Survival And Transmission, Supreet Khanal

Biomedical Sciences Theses & Dissertations

Vector-borne diseases (VBDs) are illnesses transmitted to humans and other animals by arthropods such as ticks, mosquitoes, and fleas. These arthropod vectors transmit infectious pathogens such as viruses, bacteria, and protozoa, to humans during blood-feeding. We have very few control strategies to treat or control these diseases. Human anaplasmosis, caused by the bacterium Anaplasma phagocytophilum, is the second most common tick-borne disease in the United States. This work defines three studies elucidating Anaplasma phagocytophilum-mediated modulation of cell signaling in mammalian cells and arthropod vector Ixodes scapularis ticks.

The first study focused on mammalian PI3 kinases signaling in regulating …