Comprehensive Investigation Into The Molecular Mechanisms Driving The Emergence Of Emm4 Group A Streptococcus, Chioma Odo, Samuel A Shelburne, Anthony R. Flores, Steven J Norris, Anna Konovalova, Blake Hanson

Dissertations & Theses (Open Access)

Abstract

Comprehensive Investigation into the Molecular Mechanisms Driving the Emergence of emm4 Group A Streptococcus

Chioma Modeline Odo, M.S.

Advisory Professor: Samuel A. Shelburne, MD, Ph.D.

The major gram-positive bacterium group A Streptococcus (GAS) is a model organism for studying microbial epidemics as it is well known to cause infections that occur in waves. GAS strains are grouped based on the composition of the N-terminal sequence of the M protein which is encoded by the emm gene. With the advent of large-scale whole genome sequencing, GAS clonal emergence events in emm1, emm3, and emm89 types have been identified …

Interactions Between Black Soldier Fly Larvae (Hermetia Illucens) And Pathogenic Bacteria In Culled Potato Waste, Matthew A. Moyet

Electronic Theses and Dissertations

The focus of this dissertation is to investigate the feasibility and safety of rearing black soldier fly larvae (Hermetia illucens) on culled potato waste in the presence of pathogens. World food and feed supplies remain insufficient while the demand for alternative protein sources is steadily increasing. Recycling organic waste into ingredients of animal feeds using black soldier larvae, which are omnivorous saprotrophs native to North America, is a rapidly emerging technology that shows great promise for creating circular agricultural systems. To optimize this technology on an industrial scale, assessment of rearing conditions on different feeding substrates and the …

Inhibition Of Pro-Inflammatory Lipid Mediators By Yersinia Pestis., Amanda Brady

Electronic Theses and Dissertations

Yersinia pestis causes the human disease known as plague. A key manifestation of plague is a delayed inflammatory response. Because this delay in inflammation is required for virulence, I was interested in defining the molecular mechanisms used by Y. pestis to evade immune recognition. Eicosanoids are produced early during infection and necessary to initiate a rapid inflammatory response. Despite the importance of these lipids in mediating inflammation, the role of eicosanoids during plague has not been previously investigated. Using an intranasal mouse model infection, I determined the kinetics of eicosanoid synthesis during pneumonic plague. I further demonstrated that LTB_{4 …}

Antimicrobial Activity Of Cat Flea (Ctenocephalides Felis) Gut Proteins On Different Days After Blood Feeding, Dhruva K. Karnik

Honors College Theses

Cat fleas (Ctenocephalides felis) are a blood-feeding ectoparasitic insect and a common domestic pest found throughout the world. Because of their reliance on host blood, fleas are exposed to blood-borne pathogens; however, the flea gut lumen is a hostile environment for microbial colonization. For example, the gut epithelia differentially express immune genes in response to feeding. In the present study, we measured the antimicrobial activity of gut proteins from cat fleas at different days after feeding (2, 5, 7, and 14). Dissected flea guts were homogenized, passed through a syringe filter, and measured in a protein assay kit. …

Role Of Toll-Like Receptor 2 In Macrophage Recognition And Response To Borrelia Burgdorferi, Yukiye A. Koide

Master's Theses

Lyme disease is the most common vector-borne disease in the US and will experience an uptick as the insect host, the ixodid tick, gains habitat with climate change. The causative agent of Lyme disease, Borrelia burgdorferi, is recognized by Toll-like receptor 2 (TLR2), which initiates the innate immune response. Here, I used ELISA and SEAP detection assays to determine that knocking out TLR2 in THP-1 macrophages reduces the amount of NFkB activation, as well as IL-10 and IL-1β secretion. Then, I used fluorescence microscopy and Incucyte assays to quantify the amount of phagocytosis performed by wild-type and knock-out THP-1 cells. …

Transcriptional Induction Of Immune Pathway Genes And Subsequent Antibacterial Activity In The Digestive Tract Of The Cat Flea (Ctenocephalides Felis)., Katie A. Weber

Electronic Theses and Dissertations

Fleas (Order Siphonaptera) are ectoparasites that serve as vectors of several human diseases (cat scratch disease, flea-borne spotted fever, murine typhus, and plague). Typically, these pathogens are acquired through the ingestion of a host-derived bloodmeal; thus, the lumen of the gut is the first barrier encountered by imbibed pathogens. During the early stages of infection, microbes come into contact with surrounding midgut epithelial cells which trigger a series of host responses to combat local infection. Specifically, pathogen recognition leads to intracellular signaling and an increase in the production of antimicrobial peptides (AMPs) via the IMD and Toll immune pathways. While …

Migration-Associated Variation In Blood Parasitism, Body Condition, And Stress In Gambel’S White-Crowned Sparrows (Zonotrichia Leucophrys Gambelii), Julianna Deibel

Scripps Senior Theses

Migration is a widespread behavior in animals which both causes and is motivated by fluctuations in nutrient availability. Migration is ecologically important, as it connects areas of differing primary productivities and carries pathogens over distance. The relationship between migration and disease is complex, sensitive to anthropogenic disturbance, and influenced by ecological cycles as well as host, vector and parasite life cycles. Four central migration-infection mechanisms have been proposed: migratory susceptibility, migratory exposure, migratory escape, and migratory culling. These mechanisms may yield increased or decreased infection post-migration, based on migration’s physiological tax and the concentration of pathogens along migratory pathways.

To …

Endogenous Glucocorticoid Signaling Is Required For Normal Macrophage Response To H. Pylori Infection, Stuti Khadka

Graduate Theses, Dissertations, and Problem Reports

Gastric cancer is the fifth leading cause of cancer-related deaths worldwide, affecting millions of people. H. pylori is the strongest risk factor for gastric cancer, with about 90% of the cases strongly associated with H. pylori infection. Half of the world's population is infected with this bacterium. However, only a small subset of the infected population (1-3 %) go on to develop gastric cancer. Diagnosis of the disease at an early stage is the biggest challenge because of the widespread prevalence of H. pylori infection and a long asymptomatic phase before the advanced stages. Patients are left with limited treatment …