Parasitology Commons^™

An Investigation Of Entamoeba Histolytica Chitin Synthases And Other Encystation Factors In Early Encystation, John N. Talledo

All Theses

Entamoeba histolytica is a food-and-water-borne human protozoan pathogen that relies on a two-stage life cycle for successful proliferation outside of the host. E. histolytica exists in its dormant cyst form while outside of its host and converts to the motile trophozoite (amoeba) form in the small intestine. The trophozoites colonize the large intestine to cause symptomatic disease in ~10% of infections, resulting in ~100 million cases of amoebic dysentery each year. Trophozoites can convert back to the cyst form, which is shed in feces to continue the infection cycle.

Currently, there is a lack of understanding of the exact molecular …

An Assessment Of Disease Risks, Population Genetics, And Spatial Ecology Of Appalachian Cottontails (Sylvilagus Obscurus) And Snowshoe Hares (Lepus Americanus) In West Virginia, Usa, Madison Leigh Miller

Graduate Theses, Dissertations, and Problem Reports (ETD)

Snowshoe hares (Lepus americanus) occupy a large range across the United States and Canada. While snowshoe hare populations are generally considered stable in the interior of their range, populations along range edges are experiencing declines, possibly driven by climate-related factors such as seasonal coat color mismatch. West Virginia represents one of the southernmost extents of the species’ range, yet little is known about the population genetic status or population sizes of snowshoe hares in the state. Appalachian cottontails (Sylvilagus obscurus) are another lagomorph species found in West Virginia. This species experienced a historical decline and currently …

Individual, Social, And Environmental Factors Associated With Patterns Of Parasitic Infection In Capuchin Monkeys (Cebus Imitator), Megan C. Henriquez

Dissertations, Theses, and Capstone Projects

Parasites, and the infectious diseases they carry, are thought to have significantly impacted our evolutionary trajectory for millennia. Exploring how parasites are acquired and transmitted by their hosts in wild, natural populations is integral to understanding how similar processes may have shaped host-parasite co-evolutionary relationships over time. However, parasitological studies in humans and in non-human primates have produced inconsistent results, highlighting the dynamic, nuanced, and unique relationships individual parasites have with their hosts. These relationships are largely regulated by variation in factors at host, social, and environmental levels. Characteristics unique to the host (e.g., age and sex), factors pertaining to …

Analytical Approaches For Identification Of Essential Genomes Of Plasmodium Knowlesi And Babesia Divergens, Sida Ye

Graduate Doctoral Dissertations

Apicomplexa constitute a large phylum of single-celled, obligate intracellular protozoan parasites. Notably, Plasmodium spp. and Babesia spp. are apicomplexan parasites that infect red blood cells. Plasmodium species are the causative agent of malaria and are transmitted by Anopheles mosquitoes, affecting large human populations, whereas Babesia spp., transmitted through the bite of Ixodes ticks cause babesiosis.

In this dissertation, we investigate the essential genome of these parasites using high-throughput transposon mutagenesis. Identifying the essential genome is key to finding new drug targets and understanding resistance mechanisms, a crucial pursuit given the rising resistance to frontline antimalarial drugs and the challenges …

African Sleeping Sickness: From Basic Biology To Future Directions, Riddhi R. Patel

All Theses

African Sleeping Sickness is a Neglected Tropical Disease (NTD) which poses a significant health risk to impoverished populations in 36 Sub-Saharan African countries. It is a devastating disease caused by the protozoan parasite Trypanosoma brucei, which is transmitted to mammals via the bite of infected tsetse flies. The disease manifests in two stages: the hemolymphatic stage and the meningoencephalitic stage. In the latter stage, it invades the Central Nervous System (CNS) and can be fatal if left untreated. It is caused by morphologically indistinguishable species of Trypanosoma brucei in both humans and animals, where in humans it is known as …

Avian Symbionts Of Sulawesi: Identifying And Correlating Malaria Parasites And The Microbiome In Communities Of Endemic Avian Hosts, Rachael Joakim

Dissertations, Theses, and Capstone Projects

Since the evolution of complex organisms, there have been communities of symbionts inhabiting them. Thanks to the development of parallel sequencing techniques, DNA of entire microbial communities can be sequenced from a single sample. Some microbes can be parasitic in nature, such as Haemosporida, an order of eukaryotes causing malaria. While most symbionts form a more commensal host relationship in wild systems, host-symbiont dynamics can vary in pathogenicity based on biotic and abiotic factors. In vertebrates, microbial communities in the gut play a major role in host function, including immune responses to Haemosporida. Though this relationship is most commonly explored …

Genomic Studies Of The Equine Bloodworm, Strongylus Vulgaris, Nichol Ripley

Theses and Dissertations--Veterinary Science

Strongylus vulgaris is the most pathogenic nematode parasite of grazing horses worldwide. This gastrointestinal parasitic nematode is in the family Strongylidae under the subfamily Strongylinae, or Strongylins. While the epidemiology, complete life cycle, and high pathogenicity of the fourth and fifth larval stages of S. vulgaris are well established, we understand very little about its biology. This parasite is renowned for its unique life cycle and capacity to cause arterial damage, leading to significant health and economic impacts for the equine industry. It also is the most intensively documented Strongylin; however, S. vulgaris has yet to gain drug resistance as …

Leucocytozoon Cariamae N. Sp. And Haemoproteus Pulcher Coinfection In Cariama Cristata (Aves: Cariamiformes): First Mitochondrial Genome Analysis And Morphological Description Of A Leucocytozoid In Brazil, Lis Marques De C. Vieira, Pedro Henrique O. Pereira, Daniel Ambrózio Da Rocha Vilela, Irène Landau, M. Andreína Pacheco, Ananias A. Escalante, Francisco C. Ferreira, Érika Martins Braga

Harold W. Manter Laboratory of Parasitology: Library Materials

The distribution of avian haemosporidians of the genus Leucocytozoon in the Neotropics remains poorly understood. Recent studies confirmed their presence in the region using molecular techniques alone, but evidence for gametocytes and data on putative competent hosts for Leucocytozoon are still lacking outside highland areas. We combined morphological and molecular data to characterize a new Leucocytozoon species infecting a non-migratory red-legged seriema (Cariama cristata), the first report of a competent host for Leucocytozoon in Brazil. Leucocytozoon cariamae n. sp. is distinguished from the Leucocytozoon fringillinarum group by its microgametocytes that are not strongly appressed to the host cell …

Investigating The Role Of Bromodomain Proteins On Histone Post-Translational Modifications In Toxoplasma Gondii, Joshua Steven Berthiaume

Honors Theses and Capstones

Toxoplasma gondii is a prevalent pathogenic parasite that infects approximately 25 percent of the US population. For the parasite to successfully establish and maintain infection in its host, properly controlled regulation of gene expression is critical. One way Toxoplasma regulates gene expression is through modification of histone proteins that bind to DNA and can control gene accessibility. Acetylation is a modification that is added to histones that changes chromatin structure to enhance gene activation. Histone acetylation can also regulate gene expression by recruitment of important regulators such as bromodomain proteins (BDP). A previous study showed that loss of the bromodomain …

Anti-Tick Vaccine Candidate Subolesin Is Important For Blood Feeding And Innate Immune Gene Expression In Soft Ticks, Krittika Nandy, Comfort Tamakloe, Daniel E. Sonenshine, Hameeda Sultana, Girish Neelakanta

Biological Sciences Faculty Publications

Subolesin is a conserved molecule in both hard and soft ticks and is considered as an effective candidate molecule for the development of anti-tick vaccine. Previous studies have reported the role of subolesin in blood feeding, reproduction, development, and gene expression in hard ticks. However, studies addressing the role of subolesin in soft ticks are limited. In this study, we report that subolesin is not only important in soft tick Ornithodoros turicata americanus blood feeding but also in the regulation of innate immune gene expression in these ticks. We identified and characterized several putative innate immune genes including Toll, Lysozyme …

The First Complete Genome Of The Simian Malaria Parasite Plasmodium Brasilianum, Marko Bajic, Shashidhar Ravishankar, Mili Sheth, Lori A. Rowe, M. Andreina Pacheco, Dhruviben S. Patel, Dhwani Batra, Vladimir Loparev, Christian Olsen, Ananias A. Escalante, Fredrik Vannberg, Venkatachalam Udhayakumar, John W. Barnwell, Eldin Talundzic

Harold W. Manter Laboratory of Parasitology: Library Materials

Naturally occurring human infections by zoonotic Plasmodium species have been documented for P. knowlesi, P. cynomolgi, P. simium, P. simiovale, P. inui, P. inui-like, P. coatneyi, and P. brasilianum. Accurate detection of each species is complicated by their morphological similarities with other Plasmodium species. PCR-based assays offer a solution but require prior knowledge of adequate genomic targets that can distinguish the species. While whole genomes have been published for P. knowlesi, P. cynomolgi, P. simium, and P. inui, no complete genome for P. brasilianum has …

Unraveling The Complex Interactions Between Members Of The Schistosoma Haematobium Group And Bulinus Snails In And Around Lake Victoria In West Kenya, Caitlin Raiselle Babbitt

Biology ETDs

Schistosoma haematobium, the agent of urogenital schistosomiasis, and related schistosomes are transmitted by members of the genus Bulinus. Each of the 38 Bulinus species vary in their ability to vector schistosome species and non-schistosome trematodes resulting in a patchwork of snail-parasite compatibilities. Accurately identifying snail intermediate hosts and the disease-causing parasites they transmit is critical for snail control strategies and the management of human schistosomiasis. Towards these ends, this thesis identifies bulinid species and the parasites they transmit and implicates certain species in the transmission of S. haematobium. The thesis also includes a systematic review of methods …

Morphometric And Molecular Characterization Of An Unpigmented Haemosporidian Parasite In The Neotropical Turnip-Tailed Gecko (Thecadactylus Rapicauda), Nubia E. Matta, Leydy P. González, Mario Vargas-Ramírez, Gediminas Valkiūnas, Ananias A. Escalante, M. Andreína Pacheco

Harold W. Manter Laboratory of Parasitology: Library Materials

Morphological traits from blood stages have been the gold standard for determining haemosporidian parasite species. However, the status of some taxa and the value of such traits in parasites from reptiles remain contentious. The scarce sampling of these species worsens the situation, and several taxa lack molecular data. A survey was performed in the Magdalena Department in Colombia, where 16 species of reptiles were captured. A peculiar haemosporidian parasite was found in the Turnip-tailed gecko Thecadactylus rapicauda. This haemosporidian does not show malarial pigment in blood stages under light microscopy; thus, it fits the Garnia genus’s characters belonging to …

Mitochondrial Dna Diversity, Parasite And Pathogen Occurrence, And A Potential Disease Vector In Managed And Unmanaged Honey Bee, Apis Mellifera L. Populations, Dylan Cleary

Graduate Theses and Dissertations

The western honey bee, Apis mellifera L., is a globally important pollinator plagued by several harmful stressors impacting colony health and survival. At least eight A. mellifera subspecies were imported and continue to be the genetic ancestors of U.S. honey bee populations today. Successive genetic bottle-neck events have led to reduced genetic diversity in U.S. honey bees. First, the subset of subspecies imported into the U.S. represents only a third of A. mellifera subspecies. Next, the parasitic varroa mite reduced managed and feral populations. Third, ongoing breeding practices have selected for traits from a single genetic lineage and bred from …

Investigating Granulopoiesis Of Neutrophils From Myeloblasts In The Bone Marrow Post Novel Anti-Schistosoma Compound Treatment, Sarah Alsuleiman, Paul Davis

Theses/Capstones/Creative Projects

Schistosomiasis, a commonly neglected tropical disease, is a waterborne parasitic worm infection able to infect through direct skin penetration. This disease affects approximately 270 million people worldwide and ranks only second to malaria as a leading infectious disease. Although some possible alternatives are emerging, currently, the most effective drug treatment is praziquantel (PZQ). However, PZQ is only effective against the adult stage of the worm, allowing juvenile worms to progress in the infection. Additionally, Schistosoma worms are developing resistance to this drug as reduced efficacy has been noted. Thus, the need for drug discovery and testing is increased. SA01, a …

Why Plasmodium Vivax And Plasmodium Falciparum Are So Different? A Tale Of Two Clades And Their Species Diversities, Ananias A. Escalante, Axl S. Cepeda, M. Andreína Pacheco

Harold W. Manter Laboratory of Parasitology: Library Materials

The global malaria burden sometimes obscures that the genus Plasmodium comprises diverse clades with lineages that independently gave origin to the extant human parasites. Indeed, the differences between the human malaria parasites were highlighted in the classical taxonomy by dividing them into two subgenera, the subgenus Plasmodium, which included all the human parasites but Plasmodium falciparum that was placed in its separate subgenus, Laverania. Here, the evolution of Plasmodium in primates will be discussed in terms of their species diversity and some of their distinct phenotypes, putative molecular adaptations, and host–parasite biocenosis. Thus, in addition to a current …

Rickettsial Pathogen Perturbs Tick Circadian Gene To Infect The Vertebrate Host, Supreet Khanal, Vikas Taank, John F. Anderson, Hameeda Sultana, Girish Neelakanta

Biological Sciences Faculty Publications

Ixodes scapularis is a medically important tick that transmits several microbes to humans, including rickettsial pathogen Anaplasma phagocytophilum. In nature, these ticks encounter several abiotic factors including changes in temperature, humidity, and light. Many organisms use endogenously generated circadian pathways to encounter abiotic factors. In this study, we provide evidence for the first time to show that A. phagocytophilum modulates the arthropod circadian gene for its transmission to the vertebrate host. We noted a circadian oscillation in the expression of arthropod clock, bmal1, period and timeless genes when ticks or tick cells were exposed to alternate 12 h …

Genomic Approaches To Uncovering The Coevolutionary History Of Parasitic Lice [Review], Kevin P. Johnson

Harold W. Manter Laboratory of Parasitology: Library Materials

Next-generation sequencing technologies are revolutionizing the fields of genomics, phylogenetics, and population genetics. These new genomic approaches have been extensively applied to a major group of parasites, the lice (Insecta: Phthiraptera) of birds and mammals. Two louse genomes have been assembled and annotated to date, and these have opened up new resources for the study of louse biology. Whole genome sequencing has been used to assemble large phylogenomic datasets for lice, incorporating sequences of thousands of genes. These datasets have provided highly supported trees at all taxonomic levels, ranging from relationships among the major groups of lice to those among …

Amblyomma Quadricavum (Schulze, 1941) (Acari:Ixodidae): First Description Of The Nymphal Stage And Phylogenetic Assessment Of Its Taxonomic Status, Ashleigh V. Riggs

College of Graduate Studies: Theses & Dissertations

The hard tick (Acari: Ixodidae) Amblyomma quadricavum (Schulze, 1941) is a parasite of snakes and is endemic to the Caribbean region. Morphological characters of this species, namely its rudimentary eye structures, have led to debate about its taxonomic status. The species was originally assigned to the genus Aponomma. However, with revisions of the genus Aponomma, and the recent creation of new genera created for some basal former-Aponomma, it has been suggested that perhaps Amblyomma quadricavum might be a close relative of Robertsicus elaphensis, the Trans-Pecos rat snake tick of the southwest United States and New Mexico, another eyeless former-Aponomma species …

Diversity And Host Specificity Of Nycteribiid Bat Flies (Diptera: Nycteribiidae) In Kenya, Taylor Verrett

Masters Theses & Specialist Projects

Bat flies (Diptera: Nycteribiidae and Streblidae) are hematophagous ectoparasites of bats distributed globally. Members of Nycteribiidae are morphologically constrained relative to streblids, and are united by their lack of wings, dorso-ventrally compressed bodies, and a primary distribution across the Eastern hemisphere. Bats are principal reservoirs of infectious diseases, including viral zoonoses of important consideration to human health, but the overall high host specificity of bat flies has largely been thought to curb their potential as inter-specific vectors of bat-borne pathogens. However, nycteribiid diversity and host associations remain critically understudied in some geographic regions, and rare examples of nycteribiid bat flies …

Insights Into Leptopilina Spp. Immune-Suppressive Strategies Using Mixed-Omics And Molecular Approaches, Brian Wey

Dissertations, Theses, and Capstone Projects

Host-parasite interactions influence the biology of each over the course of evolution. Parasite success allows for the passage of potent virulence strategies from generation to generation. Host success passes stronger immunity and resistance strategies to the following generations as well. Only by studying both partners within their natural contexts can we begin to understand the relationship between the two and how immune mechanisms and virulence strategies interact as a molecular arms race.

In this work, we focus on a natural host-parasite pair, the Drosophila-Leptopilina model. Leptopilina species are parasites of several fruit fly species, including Drosophila melanogaster. This model …

Disease Prevalence And The Population Genetic Structure Of Crassostrea Virginica Along The Georgia Coast, Sarah Batchelor

College of Graduate Studies: Theses & Dissertations

The Eastern Oyster, Crassostrea virginica, is an ecologically important species that plays a role in protecting shorelines, water filtration, and providing habitat and food for various fish species. Perkinsus marinus and Haplosporidium nesloni are two pathogens currently affecting oyster populations. These pathogens have both been documented as causes of mass mortality events along the East coast. They greatly diminish the health of oysters, resulting in the degradation of oyster tissue, reduction in growth and reproductive ability, and may cause death. In this study, wild oysters were collected from eleven locations along the Georgia coast to investigate the presence, intensity, …

Microbiomes Of Blood-Feeding Arthropods: Genes Coding For Essential Nutrients And Relation To Vector Fitness And Pathogenic Infections. A Review, Daniel E. Sonenshine, Philip E. Stewart

Biological Sciences Faculty Publications

Blood-feeding arthropods support a diverse array of symbiotic microbes, some of which facilitate host growth and development whereas others are detrimental to vector-borne pathogens. We found a common core constituency among the microbiota of 16 different arthropod blood-sucking disease vectors, including Bacillaceae, Rickettsiaceae, Anaplasmataceae, Sphingomonadaceae, Enterobacteriaceae, Pseudomonadaceae, Moraxellaceae and Staphylococcaceae. By comparing 21 genomes of common bacterial symbionts in blood-feeding vectors versus non-blooding insects, we found that certain enteric bacteria benefit their hosts by upregulating numerous genes coding for essential nutrients. Bacteria of blood-sucking vectors expressed significantly more genes (p < 0.001) coding for these essential nutrients than those of non-blooding insects. Moreover, compared to endosymbionts, the genomes of enteric bacteria also contained significantly more genes (p < 0.001) that code for the synthesis of essential amino acids and proteins that detoxify reactive oxygen species. In contrast, microbes in non-blood-feeding insects expressed few gene families coding for these nutrient categories. We also discuss specific midgut bacteria essential for the normal development of pathogens (e.g., Leishmania) versus …

Complete Genome Sequence Of Rickettsia Parkeri Strain Black Gap, Sandor E. Karpathy, Christopher D. Paddock, Stephanie L. Grizzard, Dhwani Batra, Lori A. Rowe, David T. Gauthier

Biological Sciences Faculty Publications

A unique genotype of Rickettsia parkeri, designated R. parkeri strain Black Gap, has thus far been associated exclusively with the North American tick, Dermacentor parumapertus. The compete genome consists of a single circular chromosome with 1,329,522 bp and a G+C content of 32.5%.

Analyses Of The Expression, Immunohistochemical Properties And Serodiagnostic Potential Of Schistosoma Japonicum Peroxiredoxin-4, Minh-Anh Dang-Trinh, Jose Ma. M. Angeles, Kharleezelle J. Moendeg, Adrian Miki C. Macalanda, Thu-Thuy Nguyen, Luna Higuchi, Shotaro Nakagun, Masahi Kirinoki, Yuichi Chigusa, Yasuyuki Goto, Shin-Ichiro Kawazu

Biology Faculty Publications

Background

Schistosoma japonicum, which inhabits the mesenteric vein of the mammalian hosts for about 20 to 30 years, is subjected to the oxidative stresses from the host defense mechanism during their intra-mammalian stages. To counteract this host immune attack, the parasite utilizes their antioxidant system for survival inside the host. Peroxiredoxins (Prxs), thiol-specific antioxidant proteins, play an essential role for protecting the parasite against oxidative stress by reducing hydrogen peroxide to water. Only three types of 2-Cys Prxs have been previously characterized in S. japonicum whereas a fourth Prx has been identified for Schistosoma mansoni as Prx-4. A sequence …

Analysis Of Genetic Structure And Pathogen Dynamics Of Ixodes Scapularis In Southwestern Virginia, Leemu Jackson

Undergraduate Honors Theses

Ixodes scapularis, or the blacklegged tick, is the primary vector of Borrelia burgdorferi. This pathogen is the causative agent of Lyme disease, the most common vector-transmitted disease in the United States. Although I. scapularis is distributed throughout the eastern U.S., Lyme disease is only considered endemic in the northeastern region of the country. Prior to 2007, Lyme disease was uncommon in Virginia, but since then cases of Lyme disease have increased dramatically with a hotspot forming in the Roanoke-Blacksburg area. The purpose of the current study was to determine whether B. burgdorferi prevalence and the genetic structure of I. …

Knemidokoptes Mites And Their Effects On The Gripping Position Of Steller’S Jay Feet, Wade M. Burris

Cal Poly Humboldt theses and projects

Steller’s jays (Cyanocitta stelleri) with swollen legs and feet resembling the signs of scaly leg have been commonly seen around Arcata, California, USA. These signs are thought to be caused by knemidokoptic mites, a group of parasites specialized at exploiting a range of avian hosts. I compared the gripping position in the feet of jays with variable signs of this condition as an index of their ability to perch, confirmed the presence of mites and identified them to the nearest species using genetic analysis, and compared the relatedness of the cytochrome oxidase subunit I (COI) gene between mites …

Analysis Of Changes In Genes That Lead To Antibiotic Resistance In Klebsiella Pneumoniae 43816, Jasmine R. Anderson

UNF Graduate Theses and Dissertations

Klebsiella pneumoniae is a Gram-negative bacterium responsible for nosocomial infections such as blood stream infections, meningitis, and septicemia. Clinical isolates confirm K. pneumoniae is increasingly antibiotic resistant (AR) making treatment more difficult. While bacterial exposure to antimicrobial substances is a known cause of the AR phenotype, there still exists gaps in knowledge about the genetic changes responsible for this fitness change. The laboratory Klebsiella pneumoniae 43816 (ATCC 43816) was exposed to sublethal concentrations of Cephalothin for a 14-day period. At the end of the experimental treatment, the adapted population acquired clinical antibiotic resistance along with phenotypic and morphological changes. The …

The Sucking Louse Fauna Of Mongolian Rodents: Host Associations, Molecular Phylogenetics And Description Of Two New Species, Chase N. Robinson

Honors College Theses

This study aimed to screen Mongolian rodents for sucking lice (Insecta: Phthiraptera: Anoplura) to better understand host-parasite associations for this understudied region. Nine species, including 3 previously undescribed, from 4 genera were identified. A molecular phylogeny based on 2 mitochondrial genes of collected louse specimens is included.

Blood Parasites Infecting The Hoatzin (Opisthocomus Hoazin), A Unique Neotropical Folivorous Bird, M. Andreína Pacheco, M. Alexandra García-Amado, Jaime Manzano, Nubia E. Matta, Ananias A. Escalante

Harold W. Manter Laboratory of Parasitology: Library Materials

The Hoatzin (Opisthocomus hoazin) is the only extant member of the order Opisthocomiformes. This unique South American bird lives in the riparian lowland vegetation characteristic of the Amazon and Orinoco basins. Hoatzins nest in communal social units close to water bodies; they are strictly folivores being the only bird with pregastric fermentation in the crop. Because of the complex logistics involved in capturing this bird, there is a knowledge gap on its parasites. This study documents two distant lineages of haemosporidian parasites (Plasmodium spp.) in a juvenile and two adults sampled in the Cojedes state, Venezuela. Although …