Life Sciences Commons^™

Health Assessment Of Two Reintroduced Populations Of American Martens (Martes Americana) In Michigan, Maria Catherine Spriggs

Doctoral Dissertations

The American marten (Martes americana) was extirpated from Michigan during the early-20th century due to loss of vast areas of mature conifer forest and unregulated trapping. The species was reintroduced into the Upper Peninsula (UP) and Northern Lower Peninsula (NLP) during the mid-20th century. While the American marten population in the UP has grown and is doing well, the population in the NLP has been less successful. The reasons for the limited success of the NLP population are unknown, but may include lack of suitable habitat, limited reproductive success, poor genetic diversity, disease, or negative environmental impacts. American …

Investigations Into The Cross-Infectivity Of Nematode Parasites Of Cattle And Sheep, Eva Marie Wray

Graduate Theses and Dissertations

The existence of anthelmintic resistance is not singular in parasite species, host species or geographic region. It has become a problem of worldly stature, especially when considering sheep nematodes. Recommendations have been modified from chemical-based control to multipart, managerial intervention. Compared with nematodes of cattle, the worldwide resistance of sheep nematodes to anthelmintic remedies is much more pronounced and urgent. As the resistance to essentially all anthelmintic classes approaches a cautionary level, the implementation of non-chemical controls has grown increasingly essential. Six-6 to 8 month old Holstein steer calves, six-5 month old Katahdin ram lambs and eight-5 month old Suffolk …

Examination Of The Chagas Disease Vector, Triatoma Gerstackeri, In The Lower Rio Grande Valley, Alfredo Flores

Theses and Dissertations

Chagas disease is caused by the protozoan parasite Trypanosoma cruzi, which is carried by an insect vector of the family Reduviidae, and of the subfamily Triatomina. The species Triatoma gerstaeckeri is identified as the primary vector of T. cruzi within the Rio Grande Valley. Species of Triatoma gerstaeckeri were trapped in La Sal del Rey National Refuge in 2012 and 2013.

Data indicates a seasonal dispersal pattern of activity for T. gerstaeckeri. Optimal time of capture was between 1-2 hours after sunset. Different methods were utilized to determine the best combination of lures. Results indicate that the UV-light alone is …

A Forward Genetic Screen Identifies Factors Associated With Fever Pathogenesis In Plasmodium Falciparum, Phaedra J. Thomas

USF Tampa Graduate Theses and Dissertations

Infectious diseases that spread from person-to-person and continent-to-continent are a cause for concern for any health entity. One such disease is malaria, a mosquito-borne infection instigated by the protozoan parasite, Plasmodium falciparum. Hundreds of millions of people are affected annually and it is responsible for nearly 1 million deaths. It is the most fatal species causing malaria and proliferates in human red blood cells with a life cycle occurring every 48 hours. At this time, the parasite’s late stage form or schizont bursts from the erythrocyte releasing immune-inducing particles and infective forms (merozoites) into the bloodstream. The merozoites go …

Expression, Localization, And Kinetic Characterization Of The Phospholipid Biosynthesis Enzyme Ctp: Phosphocholine Cytidylyltransferase From The Protozoan Parasite Leishmania Major, Justin Daniel Theodore Lange

Theses and Dissertations

The eukaryotic parasite Leishmania is the causative agent of the disease leishmaniasis. L. major is the most common of 21 species that causes visceral leishmaniasis in humans, and 30 that cause the same disease in other mammals. Visceral leishmaniasis causes fever, weight loss, and over a short amount of time, multiple organ failure, and has a 100% mortality rate within 2 years. This makes it the second largest parasitic killer in the world behind malaria. Over 90% of the worldâ??s cases of visceral leishmaniasis have been reported in underdeveloped countries of India, Bangladesh, Nepal, Sudan, Ethiopia and Brazil, with 500,000 …

Investigations Into The Incidence And Control Of Selected Parasites And Pathogens Which Infect Arkansas Horses, Stephanie Ann O'Berg Rainbolt

Graduate Theses and Dissertations

Parasite control is an important aspect of health management of horses, particularly the control of gastrointestinal (GI) parasites. Recently, treatment recommendations have involved selective use of anthelmintics in horses with fecal egg counts (FEC) greater than a specified threshold. The objectives of this study were; (1) to determine the prevalence of helminths in our area by egg and L3 determinations, (2) to determine if certain horses maintained low FEC, therefore eliminating the need to treat them on a year-round basis and (3) to determine the effectiveness of four common treatments (moxidectin, ivermectin (pioneer and generic), fenbendazole and pyrantel tartrate) via …

Phylogeny And Diversity Of Entamoeba In Cockroaches, With An Emphasis On Periplaneta Americana, Mustafa Husain Fakhri

Graduate Theses and Dissertations

While the parasitic Amoebozoan Entamoeba histolytica has been well-studied for its role in human pathogenesis, the biodiversity of invertebrate-inhabiting Entamoeba has scarcely been investigated. Using molecular methods, I searched for Entamoeba in the guts of cockroaches from four of the six Blattodean families. Entamoeba small-subunit rRNA genes were recovered from all eight species of cockroaches tested, five of which represent newly discovered hosts. Phylogenetic analysis of over 190 sequences revealed a novel and highly diverse clade of cockroach-inhabiting Entamoeba, separate from the clade predominated by vertebrate-inhabitants. These results double the known genetic diversity of Entamoeba and suggest that they may …

The Incidence Of Chagas Coinfections Amongst Acute Dengue Patients In Machala, Ecuador, Elizabeth A. Mcmahon

Honors Capstone Projects - All

Dengue fever is a febrile illness found throughout the tropics that, in severe cases, can be deadly. The most rapidly spreading of any mosquito-borne disease, dengue is re-emerging as an illness of great concern in Latin America and around the globe. The CDC estimates that as many as 400 million cases of dengue occur each year. The pathogenesis of dengue virus is complicated and acts through modulation of the host immune system. Dengue polarizes the immune system balance of T helper 1 (Th1) and T helper 2 (Th2) cells towards a Th1 inflammatory response. Parasitic infections have also been shown …

Parasite Infection Mediates Trait Tradeoffs In Fundulus Heteroclitus, Sarah Dunn

Honors College Theses

To be successful, an animal must eat, grow, and reproduce. With limited resources, there are tradeoffs between these critical life history parameters but the direction of the tradeoffs is largely unknown in a changing environment. To determine whether environmental context affects life-history tradeoffs, I surveyed and quantified investment into reproduction, growth, and a proxy for immunity (parasitism), in the mummichog, Fundulus heteroclitus, a common inhabitant of salt marshes in Georgia. Three salt marsh sites along coastal Georgia (Shellman Bluff, Skidaway Island, and Tybee Island) were selected using a proxy for anthropogenic disturbance (impervious surface), which also fell along a …

Baylisascaris Spp. In Non-Raccoon Procyonid Hosts And Assessment Of Potential Risk Of Human Exposure, Max Carlin Parkanzky

Open Access Theses

Baylisascaris procyonis (Bp) is a large roundworm of the common raccoon (Procyon lotor) which serves as the definitive host. Bp is an important cause of clinical larva migrans, including severe neurological disease, across numerous taxa including humans. Other procyonids, as well as occasionally dogs, can act as definitive hosts for this or other Baylisascaris spp. Many of these animals are becoming more common as household pets, posing a risk to people who come in contact with these animals. We have investigated whether patent Baylisascaris spp. infection exists in captive non-raccoon procyonids and if humans who contact these animals …

A Novel Population Of Natural Killer Cells Plays A Critical Role In The Depletion Of Splenic B2 B Cells During Experimental African Trypanosomiasis, Deborah Frenkel

Doctoral Dissertations

Loss of humoral immune competence in T. brucei-infected mice is associated with the apoptotic depletion of splenic transitional, marginal zone and follicular B cells as well as a depletion of CD8⁺ T cells. This occurs rapidly after infection and impairs responses to vaccine antigens in addition to responses to newly arising VSG antigenic variants, leading to uncontrolled parasite growth and death of the infected mice. Infection-induced B2 B cell and CD8⁺ T cell loss requires the presence of a novel population of natural killer (NK) cells and is mediated by a perforin-dependent process consistent with perforin- and …

Ecological And Evolutionary Interactions Between Song Sparrows (Melospiza Melodia) And Their Bloodborne Parasites, Yanina Sarquis-Adamson

Electronic Thesis and Dissertation Repository

Local adaptation is the result of natural selection operating at a local scale, such that trade-offs in fitness across different environments result in individuals having higher fitness in their place of origin than when transported into a foreign environment. Populations may become locally adapted to features of their abiotic environment, or in the case of coevolutionary arms races between hosts and parasites, to other species comprising their biotic environment. If host populations are adapted to their local (sympatric) parasites, or conversely if parasites are adapted to their local hosts, then interactions with local parasite strains may influence the fitness consequences …

Evolution Of Bat-Trypanosome Associations And The Origins Of Chagas Disease, Christian Miguel Pinto

Dissertations, Theses, and Capstone Projects

Trypanosoma cruzi is a genetically diverse parasite that causes Chagas disease, one of the most important zoonoses in the Americas. This generalist parasite of mammals belongs to a clade mostly comprised of bat parasites, the T. cruzi clade. The origins (i.e., biogeographic history and evolution of hosts associations) of this parasite are far from being understood, and the main areas that need further study are: species limits within T. cruzi sensu lato, further studies on the diversity of T. cruzi clade members and their hosts, and research on adaptations of the hosts to trypanosome infections. In this dissertation I explore …

Detecting Enzootic Leishmaniasis And American Trypanosomiasis In Stray Dogs In El Paso County, Texas And The Potential For Autochthonous Transmission To Humans, Evan James Kipp

Open Access Theses & Dissertations

Cutaneous leishmaniasis and Chagas disease (American trypanosomiasis) are two vector-borne, protozoal zoonoses whose emergence into the southern United States is a public health problem of increasing significance. Cutaneous leishmaniasis is caused by several species of intracellular protozoa in the genus Leishmania and is most often characterized by the formation of large, ulcerative skin lesions that can result in considerable scarring and permanent disfigurement. Infection with Leishmania is prevalent throughout the world in tropical and sub-tropical regions and in areas where people are regularly exposed to the hematophagous sand fly vectors that transmit the disease. Chronic infection with Trypanosoma cruzi, the …

Serine Palmitoyltransferase And Giardial Encystation, Monica Delgado

Open Access Theses & Dissertations

Giardia lamblia is a flagellated protozoan parasite responsible for chronic diarrheal disease in humans and animals. Giardia has minimal lipid synThesis machinery and the majority of its lipids are obtained from the small intestine of humans where the trophozoites colonize. Recent results from our laboratory indicate that sphingolipids (SLs) are also important for Giardia and they regulate encystation and cyst production. Only five SL genes are present in this parasite and they are differentially regulated during encystation. In my studies, I found that giardial serine palmitoyltransferase (gSPT) activity is upregulated in encysting cells, suggesting it might play an important role …

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 …

Efficacy And Resistance Potential Of Jpc-3210 In Plasmodium Falciparum, Siobhan Marie Flaherty

USF Tampa Graduate Theses and Dissertations

Combating drug resistant malaria has been historically challenging, and remains so today. Recent reports from Southeast Asia show that Plasmodium falciparum is developing resistance to even our best defenses; artemisinin-based therapies. This development threatens to become a significant challenge in controlling malaria infections worldwide, making research into developing and characterizing new antimalarial drugs increasingly important. The purpose of this study was to characterize the resistance potential of novel antimalarial compound JPC-3210 in vitro using P. falciparum clones. JPC-3210 is a new long acting drug with potential to be used in combination with fast-acting drugs like artemisinins to cure drug resistant …

Impacts Of Agrochemical Pollution On Aquatic Communities And Human Disease, Neal T. Halstead

USF Tampa Graduate Theses and Dissertations

The global human population is expected to exceed 9 billion individuals by 2050, putting greater strain on the natural resources needed to sustain such a population. To feed this many people, some expect agricultural production will have to double and agrochemical use will have to increase anywhere from two- to five-fold relative to the turn of the century. Although industrial agriculture has provided many benefits to society, it has caused declines in biodiversity, both directly (e.g., through conversion of habitat) and indirectly (e.g., through contamination of adjacent natural habitats). Agricultural activity has also been linked to increased prevalence and intensity …

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 …

Development Of Orally Bioavailable 4(1H)-Quinolones And 1,2,3,4-Tetrahydroacridin-9(10H)-Ones With Potent Anti-Malarial Activity, Jordany Richarlson Maignan

USF Tampa Graduate Theses and Dissertations

Although Malaria rates are on the decline due to the efforts of the World Health Organization and other organizations dedicated to the eradication of this disease, a relaxed attitude towards the development of new antimalarial entities would be flawed. Due to the emergence of resistance in the parasite, the almost 50% world-wide reduction in malarial death rates that have been produced over the past 15 years are threatening to be lost

New drugs are urgently needed and our approach focuses on the re-evaluation and optimization of the historic antimalarial ICI 56,780. Due to its causal prophylactic activity, along with its …

Compatibility Factors Of Fascioloides Magna Miracidia And Four Sympatric Snail Species: Miracidial Behavior And Snail Response, Bryan Rolfsen

Masters Theses

Miracidia exhibit observable host-finding behaviors, and their sympatric snails have attributes that either permit or prohibit infection. This study was designed to assess the factors involved in intermediate host finding and host-parasite compatibility in the deer liver fluke (Fascioloides magna). The main aim was to determine the extent to which the parasite and/or the intermediate host are involved in host-parasite compatibility. A secondary goal was to determine what factors may lead to miracidial transformation. The study used a panel of four sympatric snails (Lymnaea caperata, Lymnaea palustris, Lymnaea exilis, and Physa sp.) that display …