Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 9 of 9

Full-Text Articles in Life Sciences

Overexpressing Two Helicobacter Pylori Small Rnas From A Bacterial Pathogenicity-Related Chromosomal Region To Investigate Their Regulation Of Virulence Genes, Roxanne N. Mcpeck, Olivia F. Morgan, Andrea R. Castillo Phd May 2023

Overexpressing Two Helicobacter Pylori Small Rnas From A Bacterial Pathogenicity-Related Chromosomal Region To Investigate Their Regulation Of Virulence Genes, Roxanne N. Mcpeck, Olivia F. Morgan, Andrea R. Castillo Phd

2023 Symposium

The bacterial pathogen Helicobacter pylori infects the stomachs of approximately 50% of humanity, causing symptomatic disease (e.g., stomach ulcers, gastric cancer, and MALT lymphoma) in 10-15% of the infected. Colonizing the acidic, inhospitable stomach requires H. pylori to tightly regulate gene expression despite lacking many common bacterial genetic regulatory elements. The pathogen may compensate by using abundant non-protein-coding small RNAs (sRNAs) to regulate gene expression, including of infection-intensifying virulence genes. Additionally, severe disease and cancer correlate with infection by H. pylori strains that contain a nonessential chromosomal region, the cytotoxin-associated gene pathogenicity island (cagPAI). This encodes powerful virulence …


Evaluating Efficacy Of Anti-Batrachochytrium Dendrobatidis Probiotic Treatment On Pacific Chorus Frogs (Pseudacris Regilla) At Current And Modeled Climate Change Temperatures, Autumn N. Holley Jan 2023

Evaluating Efficacy Of Anti-Batrachochytrium Dendrobatidis Probiotic Treatment On Pacific Chorus Frogs (Pseudacris Regilla) At Current And Modeled Climate Change Temperatures, Autumn N. Holley

EWU Masters Thesis Collection

Amphibian populations are declining due to a variety of threats, including the chytrid fungal pathogen, Batrachochytrium dendrobatidis (Bd), the causative agent of the disease chytridiomycosis. Climate change and other stressors can have complicated interactions with amphibian disease. Some amphibian populations are less susceptible to chytridiomycosis due to factors such as symbiotic skin microbes that may inhibit Bd through secondary metabolites. There have been several attempts to develop probiotics from these symbiotic, antifungal bacteria to provide protection against Bd infection, but these studies have had mixed success. Our study evaluated anti-Bd bacteria isolated from the skin of Pacific chorus frogs (Pseudacris …


Surveillance And Monitoring Of Amphibian Pathogens And Evaluating The Impacts Of An Associated Course-Based Undergraduate Research Experience (Cure), Jennifer Perez Jan 2023

Surveillance And Monitoring Of Amphibian Pathogens And Evaluating The Impacts Of An Associated Course-Based Undergraduate Research Experience (Cure), Jennifer Perez

EWU Masters Thesis Collection

Amphibians are a highly diverse class of vertebrates and crucial for natural ecosystems, inhabiting both aquatic and terrestrial environments at different life stages. However, amphibians are facing devastating declines largely due to the disease chytridiomycosis, caused by the fungal pathogens Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal). This disease can lead to population declines, biodiversity loss, and species extinction. However, resources to study and mitigate this disease are limited and an opportunity to assist in these efforts has been created in the form of a course-based undergraduate research experience (CURE). Chapter 1 of my thesis used Roger's Diffusion of Innovations …


The Role Of The Skin Microbiome In Amphibian Pathogen Susceptibility In Turnbull National Wildlife Refuge, Krista S. Dodd Jan 2022

The Role Of The Skin Microbiome In Amphibian Pathogen Susceptibility In Turnbull National Wildlife Refuge, Krista S. Dodd

EWU Masters Thesis Collection

The fungal pathogen, Batrachochytrium dendrobatidis (Bd), has led to the decline and extinction of many amphibian populations, but some bacteria in the skin microbiome can inhibit its growth. In Turnbull National Wildlife Refuge (TNWR) in eastern Washington, Bd is highly prevalent, but the role of the skin microbiome in Bd infection dynamics have not been examined in this region. We hypothesized that frogs with lower Bd infection intensities would have higher skin bacterial diversity and more abundant anti-Bd bacteria, indicative of a more protective function. Our study combined cultureindependent and culture-dependent methods to assess the relationship between Bd and the …


Virulence Of Drosophila C Virus Increased After A Host Shift And Serial Passage In Drosophila Hosts, Katie A. Johnson Jan 2020

Virulence Of Drosophila C Virus Increased After A Host Shift And Serial Passage In Drosophila Hosts, Katie A. Johnson

EWU Masters Thesis Collection

The outcomes of novel host-pathogen interactions are unpredictable but can result in epidemics or pandemics. Exploring the initial encounter between a pathogen and a novel host species can elucidate why some pathogens successfully infect and adapt on a novel host when others fail. Much of our understanding of host virulence after host shifts was developed using serial passage experiments (SPEs) in bacteria. Three accepted SPE generalities have emerged: virulence increases on the novel host, the evolved pathogen will become less able to infect its native host, and the pathogen experiences convergent evolution. This study tests the first two generalities using …


Characterization Of Helicobacter Pylori Srnas Hpnc2525, Hpnc2600, And Hpnc2645, Brandon M. Flatgard Jan 2020

Characterization Of Helicobacter Pylori Srnas Hpnc2525, Hpnc2600, And Hpnc2645, Brandon M. Flatgard

EWU Masters Thesis Collection

Helicobacter pylori is a common microaerophilic gram-negative bacterium that infects approximately 50% of the human population. Although all H. pylori infections result in inflammation of the gastric epithelium, only 10-15% of infections are symptomatic and progress to severe gastric diseases such as gastric and duodenal ulcers, MALT lymphoma and gastric cancer. Different disease outcomes are due in part to genetic variations among H. pylori strains. Helicobacter pylori strains with a genomic region called the cytotoxin-associated pathogenicity island (cagPAI) are associated with an increased risk of severe disease. The cagPAI region encodes a type IV secretion system that transports the CagA …


Helicobacter Pylori Gene Regulation By Virulence Region Located Srnas, Veronica Janette Albrecht Jan 2020

Helicobacter Pylori Gene Regulation By Virulence Region Located Srnas, Veronica Janette Albrecht

EWU Masters Thesis Collection

Approximately 50% of the human population is infected with Helicobacter pylori, which can lead to gastrointestinal diseases such as ulcers and gastric adenocarcinoma. Helicobacter pylori strains are genetically variable, and some contain a DNA region called the cytotoxin associated gene pathogenicity island (cagPAI) that encodes virulence factors. Gastrointestinal disease associated with H. pylori are more likely to occur in infections with cagPAI positive strains. Helicobacter pylori has few known transcriptional regulators, but still must regulate expression to survive a constantly changing environment. A mechanism to facilitate this regulation was revealed in a transcriptome analysis conducted by Sharma et al. (2010) …


Impact Of Chytrid Fungus Pathogen On The Skin Microbiome Of Frogs In Northern Idaho And Turnbull National Wildlife Refuge, Washington, Philip M. Campos Jan 2020

Impact Of Chytrid Fungus Pathogen On The Skin Microbiome Of Frogs In Northern Idaho And Turnbull National Wildlife Refuge, Washington, Philip M. Campos

EWU Masters Thesis Collection

Amphibians worldwide are under threat from the infectious disease chytridiomycosis, which is caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd). Bd is associated with the population declines of an estimated 501 species, 90 of which are presumed or confirmed extinct, making this the greatest documented loss of biodiversity attributed to a disease. Researching the amphibian skin microbiome may provide solutions to conservation of amphibians. Two main relationships have been observed between Bd and the microbiome: 1) bacteria producing antifungal metabolites can inhibit Bd and improve survival against the disease and 2) infection by Bd is believed to affect the composition …


High Resolution Modeling Of Tick Density And Detection Of Rickettsia Spp. In Dermacentor Spp. Ticks At Turnbull National Wildlife Refuge, Wa, Justin L. Donahue Jan 2019

High Resolution Modeling Of Tick Density And Detection Of Rickettsia Spp. In Dermacentor Spp. Ticks At Turnbull National Wildlife Refuge, Wa, Justin L. Donahue

EWU Masters Thesis Collection

The tick species Dermacentor andersoni and Dermacentor variabilis are known vectors of pathogens. One such pathogen is the bacteria Rickettsia rickettsii, which causes Rocky Mountain spotted fever. The detection of this bacterium in ticks at Turnbull National Wildlife Refuge (TNWR) indicates a potential risk to human health. In order to follow up on this discovery, we had two separate objectives. First we developed a high resolution predictive map for Dermacentor spp. distribution across the public use area of TNWR. To do so, 50m transects (27 in total) were established across the public use area. Ticks were collected weekly within the …