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 …

Repurposing Cyclin-Dependent Kinase Inhibitors For The Discovery Of Novel Antiplasmodial Compounds, Ritam Bhowmik

Honors Undergraduate Theses

Malaria remains a major global health burden with over 282 million cases annually and rising resistance to artemisinin-based combination therapies. Plasmodium falciparum, the most lethal malaria parasite species in humans, relies on tightly regulated cell cycle progression during replication within red blood cells. Cyclin-dependent kinases (CDKs) are central regulators of eukaryotic cell division and transcription, and several CDK-like enzymes in P. falciparum, including Pfmrk and PfPK6, are essential for parasite growth and structurally distinct from human kinases. This study evaluated whether commercially available human CDK inhibitors (CDKIs) targeting cancer pathways could be repurposed as novel antimalarial compounds. A library of …

Host, Microbiome, And Parasite: How Apicomplexan Microorganisms Interact With Gut Microbiota, Senia Bu, Andrew T. Ozga

Mako: NSU Undergraduate Student Journal

The gut microbiome, a complex ecosystem of microorganisms residing in the human gastrointestinal tract, plays a crucial role in maintaining overall health. It functions in immune system regulation, digestion, and protection against pathogens. Apicomplexan parasites, such as Toxoplasma gondii, Plasmodium spp., and Cryptosporidium spp., are major pathogens that can significantly disrupt the gut microbiota, leading to alterations in microbial composition and function. This review explores the bidirectional interactions between Apicomplexan parasites and the gut microbiome, focusing on how these parasites influence microbial diversity, immune responses, and host metabolism. It examines the mechanisms by which infection-induced inflammation, altered …

In Vitro Assessment Of The Antihistomonal Activity Of Methyl Jasmonate And Jasmonic Acid, Mckayla B. Williams

Poultry Science Undergraduate Honors Theses

Histomonas meleagridis is a protozoan parasite and the causative agent of histomonosis in gallinaceous birds. There are currently no approved prevention or treatment options available for histomonosis control in the United States. Mortality in affected turkey flocks can exceed 80% which highlights the urgent need for research investigating novel strategies to mitigate histomonosis in the field. The objective of this study was to evaluate the in vitro antihistomonal and antibacterial effects of of methyl jasmonate (MeJA) and jasmonic acid (JA), two plant-derived compounds, in a xenic culture of H. meleagridis. Assays were conducted using cultured H. meleagridis (PHL strain) treated …

The Inside Scoop: Elucidating The Three-Way Relationship Between Schistosoma Mansoni, The Gut, And Vaccines, Mariam A. Mhanna

Biomedical Sciences Theses & Dissertations

Schistosomiasis is a neglected tropical disease that affects over 250 million people worldwide. This blood fluke infection burdens communities and areas with limited to no access to clean fresh water. When a host is exposed to cercariae, the infectious agent, in a body of water, it matures in the host’s circulation into adult female and male worms. Copulated adult worms migrate to the mesentery, in the case of Schistosoma mansoni, and produce eggs that can cross the intestinal barrier and get excreted in the feces to continue the lifecycle. The effects of S. mansoni infection on the host …

Characterization Of Sars-Cov-2 Replication And Transcription Complexes Via Structural And Evolutionary Approaches, Amelie Ghirardo, Ben Shabatian, Avishai Aghelian, Kyle Tau, Eleonora Gianti

Undergraduate Research

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused around 700M cases and over 7M COVID-19-related deaths recorded worldwide (World Health Organization, March 2025). Aiming to effectively combat this and other disease-causing Coronaviruses (CoV), unprecedented research efforts led to the development of new vaccines and antiviral therapies. Due to emergence of variants of concern (VOCs) with increased transmissibility, immune evasion from vaccination, and potential to resist the available treatments, SARS-CoV-2 continues to represent a major threat to global health. Hence, there is a pressing need to discover new antivirals with broad-spectrum efficacy against multiple SARS-CoV-2 variants and related CoVs. This project …

Mechanisms Of Behavioral Change In Hosts Of Toxoplasma Gondii: A Review, Olivia Grimsley

Senior Honors Theses

The parasite Toxoplasma gondii is a highly ubiquitous parasite that latently infects an estimated 33% percent of the global population. Toxoplasmosis is of obvious clinical significance due to the extremely high risks to the unborn who contract it congenitally. Less attention has been given to a more subtle aspect of latent infection, which is the behavioral alterations that are commonly experienced by those who contract the parasite. Infected individuals commonly display a variety of altered behaviors, such as increased aggression and risk-seeking behaviors, depression, higher tendency towards suicide and self-directed violence, a loss of fear response, and a greatly increased …

Schistosoma Mansoni Infection Causes Consistent Changes To The Fecal Bacterial Microbiota Of Mice Across And Within Sites, Mariam A. Mhanna, David T. Gauthier, Lisa M. Shollenberger

Biological Sciences Faculty Publications

Eggs of Schistosoma mansoni are produced by adult female worms in mesenteries of infected hosts. Eggs can cross the intestinal barrier and form granulomas in the tissue or breach and exit the host through fecal excretion. These interactions may affect the host microbiome assemblages. Given the potential for schistosomal alteration of host gut microbiome and subsequent effects on the fecal bacterial composition, it is important to conduct controlled microbiome studies on model animals. While pursuing these studies, it is important to take into account the different conditions in which microbiome studies are conducted and their consequent impacts on variability and …

Impacts Of Tick Parasitism On The Rodent Gut Microbiome, Robert J. Brinkerhoff, Joshua Pandian, Meghan Leber, Isabella D. Hauser, Holly D. Gaff

Biological Sciences Faculty Publications

Host microbiota may impact disease vector behavior and pathogen transmission, but little is known about associations between ectoparasites and microbial communities in wildlife reservoir species. We used Illumina metagenomic sequencing to explore the impacts of tick parasitism on the rodent fecal microbiome in both a field and laboratory setting. We found that tick parasitism on wild hosts was associated with variation in the fecal microbiota of both the white-footed deermouse, Peromyscus leucopus, and the southern cotton rat, Sigmodon hispidus. In a lab experiment, we detected significant changes to the fecal microbiome after experimental exposure to immature ticks in …

Natural Panola Mountain Ehrlichia Infections In Cattle In A Longitudinal Study Of Angus Beef Calves, Cierra Briggs, Drew Casey, Anna Grace Deakins, Jeremy G. Powell, Kelly Loftin, Emily G. Mcdermott

Entomology and Plant Pathology Faculty Publications and Presentations

Panola Mountain Ehrlichia (PME) is an emerging zoonotic pathogen, transmitted by Amblyomma americanum ticks in the southeastern United States. It is closely related to Ehrlichia ruminantium, the causative agent of heartwater disease. Heartwater disease is an often-fatal illness of ruminant livestock present in Africa and the Caribbean. The taxonomic relationship between PME and E. ruminantium has raised concerns about the pathogenicity of PME in livestock. To determine whether cattle could be naturally infected with PME in an endemic area, we conducted a one-year longitudinal study of Angus-breed beef calves in Fayetteville, Arkansas. One hundred seventy-seven calves born between September …

Molecular Investigation Of Tick-Borne Pathogens In Feral Swine (Sus Scrofa) From Seven Us States, Sofiane Aiche

Masters Theses

Feral swine (Sus scrofa) have been proposed as part of the lifecycles of multiple tickborne pathogens (TBP). This is a result of the increase in feral swine populations and increased tick populations and geographic ranges. Few surveys exist on the TBP relevant to human and wildlife of feral swine in the US. The aim of this study is to investigate the prevalence of 10 TBP: Anaplasma spp., Borrelia spp., Cytauxzoon felis, Hepatozoon spp., Babesia spp., Mycoplasma spp., Trypanosoma cruzi, Toxoplasma gondii, Yersinia pestis, and Rickettsia spp. A total of 87 feral swine blood samples …

Potency Of Novel Anti-Toxoplasmic Compounds, Matthias Walters

Theses/Capstones/Creative Projects

Toxoplasma gondii, the causative agent of toxoplasmosis, is an intracellular apicomplexan parasite. Toxoplasmosis is often asymptomatic, though, it can be debilitating or fatal to immunocompromised individuals and fetuses, being one of the leading causes of fetal mortality and birth defects. Toxoplasmosis is treated with a synergistic combination of drugs pyrimethamine and sulfadiazine; however, these drugs are only effective against the acute stage of infection, and the pyrimethamine is relatively cytotoxic, damaging bone marrow and causing noxious side effects. Due to these limitations, a safer alternative that targets the chronic stage of infection is needed. In this study, we tested …

Multipatch Stochastic Epidemic Model For The Dynamics Of A Tick-Borne Disease, Milliward Maliyoni, Holly D. Gaff, Keshlan S. Govinder, Faraimunashe Chirove

Biological Sciences Faculty Publications

Spatial heterogeneity and migration of hosts and ticks have an impact on the spread, extinction and persistence of tick-borne diseases. In this paper, we investigate the impact of between-patch migration of white-tailed deer and lone star ticks on the dynamics of a tick-borne disease with regard to disease extinction and persistence using a system of Itô stochastic differential equations model. It is shown that the disease-free equilibrium exists and is unique. The general formula for computing the basic reproduction number for all patches is derived. We show that for patches in isolation, the basic reproduction number is equal to the …

Frankenbacteriosis Targeting Interactions Between Pathogen And Symbiont To Control Infection In The Tick Vector, Lorena Mazuecos, Pilar Alberdi, Angélica Hernández-Jarguín, Marinela Contreras, Margarita Villar, Alejandro Cabezas-Cruz, Ladislav Simo, Almudena González-García, Sandra Díaz-Sánchez, Girish Neelakanta, Sarah I. Bonnet, Erol Fikrig, José De La Fuente

Biological Sciences Faculty Publications

(Summary) Tick microbiota can be targeted for the control of tick-borne diseases such as human granulocytic anaplasmosis (HGA) caused by model pathogen, Anaplasma phagocytophilum. Frankenbacteriosis is inspired by Frankenstein and defined here as paratransgenesis of tick symbiotic/commensal bacteria to mimic and compete with tick-borne pathogens. Interactions between A. phagocytophilum and symbiotic Sphingomonas identified by metaproteomics analysis in Ixodes scapularis midgut showed competition between both bacteria. Consequently, Sphingomonas was selected for frankenbacteriosis for the control of A. phagocytophilum infection and transmission. The results showed that Franken Sphingomonas producing A. phagocytophilum major surface protein 4 (MSP4) mimic pathogen and reduce infection …

Investigating Host Defenses Of North American Salamanders Against The Recently Emerged Chytrid Pathogen, Batrachochytrium Salamandrivorans, Kenzie Pereira

Electronic Theses and Dissertations

A recently emerged chytrid fungal pathogen, Batrachochytrium salamandrivorans (Bsal) threatens salamander biodiversity. Bsal susceptibility varies between and within salamander species, but little is known about the mechanisms underlying these differences. Susceptibility is likely influenced by numerous interacting factors, but my dissertation studied the role of host immune responses.

My first aim investigated between species differences by studying the bioactive properties of salamander skin peptides against Bsal and the related pathogen, B. dendrobatidis (Bd). Skin peptides were collected from five salamander species, used for in vitro assays, and analyzed by RP-HPLC. While skin peptides from one …

Perception Of Illness And Its Association With Willingness To Adhere To Treatment In Chronic Hepatitis C Patients With New Diagnosis Of Nonalcoholic Fatty Liver Disease, Carmel Kruse

The Eleanor Mann School of Nursing DNP Capstone Projects

Chronic liver disease is becoming the most common cause of mortality, morbidity, and utilization of healthcare services globally. Both nonalcoholic fatty liver disease (NAFLD) and chronic hepatitis C (CHC) are frequent causes of chronic liver disease. Recently, there have been significant findings on the relationship between NAFLD and CHC; patients with CHC have a higher incidence of NAFLD. The introduction of direct-acting antivirals has cured more CHC patients than ever before. Unfortunately, the current interventions for NAFLD requiring behavioral change remain ineffective. Patient’s ability to follow advice depends largely on their health beliefs; therefore, understanding their illness perception is an …

Native And Non-Native Ant Impacts On Soil Microbes, Hannah A. Stewart

Biology Theses

Organisms produce chemical weapons for defense, but target organisms can develop resistance. In their introduced range, non-native species may bring “novel weapons” against which native organisms have not co-evolved resistance. The invasive European fire ant (Myrmica rubra) may have brought antimicrobial secretions to the Northeastern United States that are novel weapons against native fungal and bacterial soil organisms. I hypothesized that M. rubra would better inhibit seed pathogens resulting in greater emergence of native myrmecochorous Viola sororia seeds and, as a side effect, more strongly inhibit arbuscular mycorrhizal fungi than a native seed dispersing ant (Aphaenogaster picea …

Thrombospondin-1 Expression And Modulation Of Wnt And Hippo Signaling Pathways During The Early Phase Of Trypanosoma Cruzi Infection Of Heart Endothelial Cells, Ashutosh Arun, Kayla J. Rayford, Ayorinde Cooley, Tanu Rana, Girish Rachakonda, Fernando Villalta, Siddharth Pratap, Maria F. Lima, Nader Sheibani, Pius N. Nde

Publications and Research

The protozoan parasite, Trypanosoma cruzi, causes severe morbidity and mortality in afflicted individuals. Approximately 30% of T. cruzi infected individuals present with cardiac pathology. The invasive forms of the parasite are carried in the vascular system to infect other cells of the body. During transportation, the molecular mechanisms by which the parasite signals and interact with host endothelial cells (EC) especially heart endothelium is currently unknown. The parasite increases host thrombospondin-1 (TSP1) expression and activates the Wnt/β-catenin and hippo signaling pathways during the early phase of infection. The links between TSP1 and activation of the signaling pathways and …

Dissecting The Role Of Actin-Myosin Motor And Calcium – Based Organelle Secretion In Motility Of Sarcocystis Neurona, Parul Suri

Theses and Dissertations--Veterinary Science

Sarcocystis neurona is a protozoan parasite that causes a rare neurological disorder in horses called Equine Protozoal Myeloencephalitis (EPM). Apicomplexa use actin-myosin based motor and organelle secretion to interact with the host cell and invade it. Despite the importance of motility and invasion-needed factors, the mechanisms by which S. neurona employs host cell association strategies to interact remains largely undefined. To address this knowledge gap, we hypothesize that just like other Apicomplexa, S. neurona utilizes actin polymerization for substrate-dependent gliding. Moreover, we also hypothesize that micronemes of S. neurona secrete proteins that are calcium-dependent. Based on previous studies in T. …

Molecular And Cellular Characterizations Of Glucosylceramide Transferase (Synthase) In Giardia Lamblia, Vanessa Enriquez

Open Access Theses & Dissertations

Giardiasis, caused by an intestinal protozoan, Giardia lamblia, is a major public health problem worldwide. Giardia infection is spread through the fecal-oral route via contaminated water and food. It is estimated that over 280 million people are infected with Giardia across the globe. Giardia is a non-invasive parasite and consists of a two-stage life cycle: trophozoites and cysts. Ingested cysts undergo excystation in the proximal small intestine, releasing two trophozoites (excyzoites). Upon reaching the distal small intestine and colonizing there, trophozoites transform into cysts by encystation. It has been reported earlier that the process of encystation induced the synThesis of …

Development And Validation Of An Isothermal Amplification Assay For Eastern Equine Encephalitis Virus, Mikayla D. Maddison

USF Tampa Graduate Theses and Dissertations

Eastern Equine Encephalitis virus (EEEV) is a neurotrophic alphavirus for which there is no effective treatment or vaccine for humans. Periodic outbreaks in the Eastern United States represent an ongoing public health problem; Florida serves as the reservoir for EEEV for the rest of the country. Reverse transcription-polymerase chain reaction (RT-PCR) is the current gold standard for molecular diagnostic testing of the presence of EEEV in vectors. However, RT-PCR is technically complex and can be difficult for mosquito control districts to utilize. In order to provide a simple, cost-effective alternative for mosquito surveillance and control, a novel one step reverse …

Effectiveness Of Pathogen-Specific Passive Antibodies To Mitigate Infectious Diseases In Apis Mellifera, Tanner Nordseth

Honors Thesis

Honeybees (Apis mellifera) are widely recognized as a vital part of the global ecosystem and the world's food supply due to their pivotal role in the pollination of both natural and agricultural flora. Colony Collapse Disorder (CCD) is an emerging phenomenon characterized by a colony's worker bees deserting the hive and leaving the queen behind. This usually results in colony failure. CCD is a multifactorial issue, with many environmental stressors and pathogens playing a role. Deformed Wing Virus (DWV) has been identified as a leading cause in this phenomenon. Paenibacillus larvae (P. larvae) is another lethal pathogen that is …

Biology And Molecular Biology Of Ixodes Scapularis, Daniel E. Sonenshine, Ladislav Šimo, Justin D. Radolf (Ed.), D. Scott Samuels (Ed.)

Biological Sciences Faculty Publications

This chapter describes the biology of the tick Ixodes scapularis in relation to its role as the vector of the Lyme disease agent, Borrelia burgdorferi. Following a review of the internal anatomy of the tick, we review basic molecular processes that contribute to an understanding of the dynamics of the tick's specialized parasitic processes, including attachment behavior, salivation; silencing of host anti-inflammatory responses to enable blood ingestion at the dermal feeding site; hemoglobin digestion and reproduction. The chapter is divided into three parts: 1) systematic and anatomical characteristics of ticks; 2) host finding, attachment, salivary disruption of host defenses, blood …

Varroa Destructor Mites Vector And Transmit Pathogenic Honey Bee Viruses Acquired From An Artificial Diet, Francisco Posada-Florez, Eugene V. Ryabov, Matthew C. Heerman, Yanping Chen, Jay D. Evans, Daniel E. Sonenshine, Steven C. Cook

Biological Sciences Faculty Publications

The ectoparasitic mite Varroa destructoris one of the most destructive pests of the honey bee (Apis mellifera) and the primary biotic cause of colony collapse in many regions of the world. These mites inflict physical injury on their honey bee hosts from feeding on host hemolymph and fat body cells/cellular components, and serve as the vector for deadly honey bee viruses, including Deformed wing virus (DWV) and the related Varroa destructor virus-1 (VDV-1) (i.e., DWV-like viruses). Studies focused on elucidating the dynamics of Varroa-mediated vectoring and transmission of DWV-like viruses may be confounded by viruses present in …

Plasmodium Impairs Antibacterial Innate Immunity To Systemic Infections In Part Through Hemozoin-Bound Bioactive Molecules., Christopher Lynn Harding

Electronic Theses and Dissertations

Despite efforts to decrease the global health burden of malaria, infections with Plasmodium species continue to cause over 200 million episodes of malaria each year which resulted in 405,000 deaths in 2018 [1]. One complication of malaria is increased susceptibility to invasive bacterial infections. Plasmodium infections impair host immunity to non-Typhoid Salmonella (NTS) through activities of heme oxygenase I (HO-I) )-induced release of immature granulocytes and myeloid cell-derived IL-10. Yet, it is not known if these mechanisms are specific to NTS. We show here, that Plasmodium yoelii 17XNL (Py) infected mice had impaired clearance of systemic Listeria monocytogenes (Lm) during …

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 …

Impact Of Seasonal And Host-Related Factors On The Intestinal Microbiome And Cestode Community Of Sorex Cinereus And Sorex Monticola, Katelyn D. Cranmer

College of Graduate Studies: Theses & Dissertations

The intestinal microbiome of mammals plays a significant role in host health and response to environmental stimuli and can include both beneficial native bacteria as well as parasitic worms. In this study, I examined the intestinal cestode and bacterial communities of two closely related species of shrew, Sorex monticola and Sorex cinereus, over a six month period in 2016. Specimens were collected approximately every three weeks from May to October from the Sangre de Cristo Mountains in Cowles, New Mexico. A total of 79 shrews were prepared with the gastrointestinal tracts removed and flash-frozen in liquid nitrogen. An additional …

Triatomines: Trypanosomatids, Bacteria, And Viruses Potential Vectors?, Caroline Barreto Viera, Yanna Reis Praça, Kaio Luis Da Silva Bentes, Paula Beatriz Santiago, Sofia Marcelino Martins Silva, Gabriel Dos Santos Silva, Flávia Nader Motta, Izabela Marques Dourado Bastos, Jaime Martins De Santana, Carla Nunes De Araújo

Harold W. Manter Laboratory of Parasitology: Library Materials

Triatominae bugs are the vectors of Chagas disease, a major concern to public health especially in Latin America, where vector-borne Chagas disease has undergone resurgence due mainly to diminished triatomine control in many endemic municipalities. Although the majority of Triatominae species occurs in the Americas, species belonging to the genus Linshcosteus occur in India, and species belonging to the Triatoma rubrofasciata complex have been also identified in Africa, the Middle East, South-East Asia, and in the Western Pacific. Not all of Triatominae species have been found to be infected with Trypanosoma cruzi, but the possibility of establishing vector transmission …

Characterization Of Tick Organic Anion Transporting Polypeptides (Oatps) Upon Bacterial And Viral Infections, Vikas Taank, Wenshou Zhou, Xuran Zhuang, John F. Anderson, Utpal Pal, Hameeda Sultana, Girish Neelakanta

Biological Sciences Faculty Publications

Background: Ixodes scapularis organic anion transporting polypeptides (OATPs) play important roles in tickrickettsial pathogen interactions. In this report, we characterized the role of these conserved molecules in ticks infected with either Lyme disease agent Borrelia burgdorferi or tick-borne Langat virus (LGTV), a pathogen closely related to tick-borne encephalitis virus (TBEV).

Results: Quantitative real-time polymerase chain reaction analysis revealed no significant changes in oatps gene expression upon infection with B. burgdorferi in unfed ticks. Synchronous infection of unfed nymphal ticks with LGTV in vitro revealed no significant changes in oatps gene expression. However, expression of specific oatps was significantly downregulated upon …

Triatomines: Trypanosomatids, Bacteria, And Viruses Potential Vectors? [Review], Caroline Barreto Vieira, Yanna Reis Praça, Kaio Luís Da Silva Bentes, Paula Beatriz Santiago, Sofia Marcelino Martins Silva, Gabriel Dos Santos Silva, Flávia Nader Motta, Izabela Marques Dorado Bastos, Jaime Martins De Santana, Carla Nunes De Araújo

Harold W. Manter Laboratory of Parasitology: Library Materials

Triatominae bugs are the vectors of Chagas disease, a major concern to public health especially in Latin America, where vector-borne Chagas disease has undergone resurgence due mainly to diminished triatomine control in many endemic municipalities. Although the majority of Triatominae species occurs in the Americas, species belonging to the genus Linshcosteus occur in India, and species belonging to the Triatoma rubrofasciata complex have been also identified in Africa, the Middle East, South-East Asia, and in the Western Pacific. Not all of Triatominae species have been found to be infected with Trypanosoma cruzi, but the possibility of establishing vector transmission …