Medicine and Health Sciences Commons^™

Genomics And Transcriptomics Approaches To Understanding Drug Resistance Mechanisms In The Malaria Parasite Plasmodium Falciparum, Justin Allan Gibbons

USF Tampa Graduate Theses and Dissertations

The malaria parasite Plasmodium falciparum is responsible for about 500,000 deaths a year and is evolving resistance to the front-line treatment of artemisinin-based combination therapy. Resistance is currently confined to South East Asia, however millions of lives will be at risk if resistance spreads to Africa. Understanding the mechanism of resistance to artemisinins would aid containment strategies to prevent the spread of artemisinin resistance. There is also an urgent need to accelerate drug discovery since drug resistance has already been documented to all existing antimalarials. Here, I report on our efforts to understand the function of the gene k13, the …

Essays In Applied Microeconomics, Lijuan Feng

USF Tampa Graduate Theses and Dissertations

Chapter 1 studies the effect of body weight on labor market outcomes. Using longitudinal data from the China Health and Nutrition Survey (CHNS) from 1989 to 2011, and both instrumental variable and fixed effects estimation to control for the endogeneity of body weight, I examine the wage effect of BMI by gender, type of residence area, and occupation. Results from linear OLS regression show a positive relationship between body weight and income for males in both rural and urban areas and females in rural areas, while a negative one for females in urban areas. After controlling for the unobserved individual …

Partial Characterization Of Plasmodium Falciparum Protein Kinase Abck2 (Pfabck2), Muhammad Khalid

USF Tampa Graduate Theses and Dissertations

Malaria is a major threat to the public health worldwide as it is affecting populations in tropical and subtropical areas globally. Among those populations are around 40% of pregnant women and children who are susceptible to this disease. Plasmodium falciparum is the most lethal agent that causes malaria in human. Currently, there is drug resistance against antimalarial drugs in parasite against treatment of malaria infections, it is essential to search for new drug targets in order to find cure and alleviate suffering of human population.

There are approximately 100 protein kinases in P. falciparum that are involved in phosphorylation of …

Spatial-Temporal Distribution Of Mosquito Larval Hot Spots In Papoli, Uganda: A Community-Based Approach To Mosquito Control, Ryan E. Tokarz

USF Tampa Graduate Theses and Dissertations

Mosquito species of the Anopheles gambaie complex are the predominant vectors of malaria transmission throughout sub-Saharan Africa. These mosquitoes tend to be endophilic, as well as anthropophilic, making them prime candidates for disease transmission. Within the same region, related mosquito vectors play a significant role in the transmission of additional human and zoonotic diseases. Furthermore, mosquito nuisance biting is an immense issue that cannot be ignored in terms of its impact on African communities. Depending on the respective factors involved, mosquito control programs throughout the continent have attempted to tackle these issues in a multitude of ways. This research approached …

Synthesis, In Vitro Characterization And Applications Of Novel 8-Aminoquinoline Fluorescent Probes, Adonis Mcqueen

USF Tampa Graduate Theses and Dissertations

Malaria is a parasitic disease that is caused by the plasmodium parasite. Plasmodium infection has affected man for thousands of years. With advances in drug discovery over the past century, malaria has evolved to possess resistance to most mainline therapeutics. This war of drug discovery vs plasmodium evolution continues to be fought to this very day, with attempts to eradicate malaria worldwide. Frontline treatments such as chloroquine, artemisinin, and atovaquone/proguanil have all seen parasitic resistance in strains of P. vivax as well as P. falciparum. While plasmodium possesses resistance to most classes of anti-malarials, the 8-aminoquinoline (8-AQ) class has …

Antimalarial Exoerythrocytic Stage Drug Discovery And Resistance Studies, Lynn Dong Blake

USF Tampa Graduate Theses and Dissertations

Malaria is a devastating global health issue that affects approximately 200 million people yearly and over half a million deaths are caused by this parasitic protozoan disease. Most commercially available drugs only target the blood stage form of the parasite, but the only way to ensure proper elimination is to treat the exoerythrocytic stages of the parasite development cycle. There is a demand for the discovery of new liver stage antimalarial compounds as there are only two current FDA approved drugs for the treatment of liver stage parasites, one of which fails to eliminate dormant forms and the other inducing …

Mechanistic Binding Insights For 1-Deoxy-D-Xylulose-5-Phosphatesynthase, The Enzyme Catalyzing The First Reaction Of Isoprenoid Biosynthesis In The Malaria-Causing Protists, Plasmodium Falciparum And Plasmodium Vivax, Matthew R. Battistini, Christopher Shoji, Sumit Handa, Leonid Breydo, David J. Merkler

Chemistry Faculty Publications

We have successfully truncated and recombinantly-expressed 1-deoxy-D-xylulose-5-phosphate synthase (DXS) from both Plasmodium vivax and Plasmodium falciparum. We elucidated the order of substrate binding for both of these ThDP-dependent enzymes using steady-state kinetic analyses, dead-end inhibition, and intrinsic tryptophan fluorescence titrations. Both enzymes adhere to a random sequential mechanism with respect to binding of both substrates: pyruvate and D-glyceraldehyde-3-phosphate. These findings are in contrast to other ThDP-dependent enzymes, which exhibit classical ordered and/or ping-pong kinetic mechanisms. A better understanding of the kinetic mechanism for these two Plasmodial enzymes could aid in the development of novel DXS-specific inhibitors that might prove useful …

Altered Intraerythrocytic Development Phenotypes Of Artemisinin-Resistant Plasmodium Falciparum Confer A Fitness Advantage, Amanda Hott

USF Tampa Graduate Theses and Dissertations

Resistance to artemisinin combination therapies (ACTs) has emerged in southeast Asia threatening the most widely used treatment against antimalarial-resistant Plasmodium falciparum worldwide. Artemisinin resistance has been associated with a reduced rate of parasite clearance following treatment with an ACT and is attributed to increased survival of ring-stage parasites. Single nucleotide polymorphisms (SNPs) in kelch gene (K13) has been associated with delayed in vivo clearance half-life of artemisinin-resistant P. falciparum and is the only known molecular marker of resistance. The absence of reliable in vitro phenotypes for artemisinin resistance has limited our understanding of the resistance mechanism(s) and fitness costs, therefore …

Immunological Characterization Of Duffy Binding Protein Of Plasmodium Vivax, Miriam Thankam George

USF Tampa Graduate Theses and Dissertations

Plasmodium vivax Duffy binding protein (DBP) is an essential ligand for reticulocyte invasion making it a premier asexual blood stage vaccine candidate. However, strain-specific immunity due to DBPII allelic variation may complicate vaccine efficacy, suggesting that an effective DBPII vaccine needs to target immune responses to conserved epitopes that are potential targets of strain-transcending neutralizing immunity. Anti DBPII monoclonal antibodies, which were previously characterized by COS7 cell binding assay as inhibitory and non-inhibitory to DBPII-erythrocyte binding, were mapped to DBPII gene fragment libraries using phage display. Inhibitory mAb 3C9 binds to a conserved conformation-dependent epitope in subdomain 3 while non-inhibitory …

Mmv Malaria Box Activity Screening In Dormant Plasmodium Falciparum Phenotypes, Sandra Galusic

USF Tampa Graduate Theses and Dissertations

The causative agent of malignant tertian malaria, Plasmodium falciparum undergoes an arrested growth phenotype of its erythrocytic stage when under drug-stress. Recent artemisinin treatment failures seem to be indicative of such induction followed by recrudescence rather than actual therapeutic failure. Likewise, P. vivax hypnozoites are the prototypic dormants and the latent infections for which they are responsible prove most difficult to treat. Dihydroartemisinin, an artemisinin-derivative, can be used to exploit this mechanism by inducing a dormant state in ring-stage P. falciparum parasites and in turn, their recovery may be used as a screening period for compounds that inhibit or foster …

Differentiating Geo-Spatiotemporal Aquatic Larval Habitats Of Anopheles Gambiae Complex In Urban Agriculture And Urban Non-Agriculture Environments In Accra, Ghana, Samia Mckeever

USF Tampa Graduate Theses and Dissertations

To meet the rising food demands of communities in Accra,Ghana, urban agriculture has been popularized as a way to increase food security and improve nutrition (Donovan et al., 2012). Urban agriculture is defined as "the cultivation of crops at both the subsistence and commercial levels including the keeping of livestock in open spaces in urban areas (Adjaye, n.d.). In Accra, urban agriculture covers 1,091 hectares, employs over one thousand people, and supplies residents with 90% of its vegetables ("Accra Metropolitan", n.d.). Further, 60% of households in Accra participate in backyard farming ("Accra Metropolitan", n.d.). Although urban agriculture provides many benefits …

Pathogenic Mechanisms And Signaling Pathways In Plasmodium Falciparum, Jennifer L. Sedillo

USF Tampa Graduate Theses and Dissertations

Plasmodium falciparum is a human intracellular parasite that is the causative agent of a deadly form of malaria. This species alone is responsible for 200 million cases of malaria annually resulting in over 1 million deaths worldwide. The excessive mortality due to P. falciparum infection is due to its ability to cause severe pathogenesis through hyperparasitemia and cytoadherence defined as the ability of infected red blood cells to adhere to host vasculature. Cytoadherence is mediated through the export of parasite proteins to the surface of the infected red blood cell (RBC). Exported proteins have been identified but the pathway for …

The Effect Of Drug Resistance On Plasmodium Falciparum Transmission And Gametocyte Development, Samantha Olivia Aylor

USF Tampa Graduate Theses and Dissertations

In order to reduce malaria prevalence worldwide, a better understanding of parasite transmission and the effect of drug resistance is needed. The effect of drug resistance on malaria transmission has been examined for some drugs, but not for mitochondrial inhibitors such as atovaquone and the current basis of malaria therapy, artemisinin. Therefore, the goal of this study was to produce gametocytes, the life cycle stage that transmits from mosquito to human, in several different drug resistant patient isolates as well as to determine the effect of drug resistance on gametocyte development and transmission. Previous studies have shown that the mutation …

Phenotypic And Genotypic Analysis Of In Vitro Selected Artemisinin Resistant Plasmodium Falciparum, Matthew Scott Tucker

USF Tampa Graduate Theses and Dissertations

Artemisinin and its derivatives provide faster clearance of parasitemia than any other antimalarial drugs and these drugs are part of frontline combination therapies in areas where drug-resistant Plasmodium falciparum exists. Clinical resistance to artemisinins is emerging on the Thailand-Cambodia border, making it imperative to investigate mechanisms of artemisinin resistance. Previous work in our laboratory showed ring-stage parasites enter a dormant state after exposure to artemisinin. We hypothesize that this period of dormancy is directly related to recrudescence and prolonged parasite clearance times in patients, and possibly resistance. The target of artemisinin is currently unknown, and potential resistance mechanisms are not …