Parasitology Commons^™

Increased Neural Activity In The Bed Nucleus Of The Stria Terminalis Of Uninfected Canaries After Observation Of Infected Conspecifics, Madeleine Chang, Sophia Santangelo, Devon Comito, Bennett Hardy, Patricia C. Lopes

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Recent evidence suggests that the immune system may be upregulated in anticipation of pathogen exposure, yet the neural mechanisms that respond to and signal impending infection risk remain poorly understood. We investigated neural responses to infection risk in uninfected hosts observing infected conspecifics, using the canary (Serinus canaria domestica)—Mycoplasma gallisepticum host–parasite system. We focused on five brain regions of interest, comprising three nodes of the social decision-making network—preoptic area, bed nucleus of the stria terminalis (BNST) and hippocampus—a stress modulatory region (paraventricular nucleus) and a visual processing region (nucleus rotundus). After 1 h of observing infected canaries, …

Contribution To The Chemotherapy Of Human Trypanosomiasis: Design, Synthesis, And Biological Evaluation Of Dimeric 2-Nitroimidazoles Against Trypanosoma Cruzi Amastigotes And Bloodstream Trypanosoma Brucei, Afonso Santine M.M. Velez, Otavio Augusto Chaves, Carlos Serpa, Fatma M. Salem, Bibo Li Ph.D., Bin Su Ph.D., Celio Geraldo Freire-De-Lima, Debra Decote-Ricardo, Marco Edilson Freire De Lima

Biological, Geological, and Environmental Faculty Publications

Effective and safe treatments for neglected tropical diseases caused by parasites, such as Chagas disease and sleeping sickness, remain lacking, posing a significant challenge for researchers worldwide. The rational design of dimeric compounds inspired solely by the pharmacophoric core of benznidazole (2-nitroimidazole) has proven to be a promising strategy for antiparasitic development. Thus, in the present work, it was increased the linker between the active units (2-nitroimidazole) to improve the interaction with TcNTR, facilitating the bioactivation of the longest dimers. Biological assays confirmed this, demonstrating that all compounds were active against replicative intracellular amastigotes of Trypanosoma cruzi (Tulahuen C2C4-LacZ). Notably, …

Bayesian Multivariate Modelling Of Lone Star (Amblyomma Americanum) Tick Life Stage Abundance And Temporal Trends To Inform Public Health Risk In Virginia, Thabo Lephoto, Henry Mwambi, Oliver Bodhlyera, Holly Gaff

Biological Sciences Faculty Publications

The increasing abundance of ticks poses a growing public health concern due to heightened human exposure to tick bites. The lone star tick (Amblyomma americanum: Ixodida: Ixodidae), a common human-biting species in the United States, has expanded its range in recent years. However, how its different life stages vary across time, habitats, and locations remains insufficiently understood. We analyzed tick abundance data collected in southeastern Virginia between 2009 and 2018, focusing on larval, nymphal, and adult life stages. A Bayesian multivariate modelling framework was used to examine seasonal patterns, habitat effects, spatial variation, and biological links between life stages. Two …

Effects Of Desiccation On Invasive Faucet Snail (Bithynia Tentaculata) And Trematode Survival, Elise Marie Jordahl

Graduate Research Theses & Dissertations

Parasitism is one of the most common and diverse life history strategies, yet relatively little is known about the role of parasites as invasive species. Invasive species, which present one of the greatest threats to biodiversity, often need to overcome adverse environmental conditions as they establish and spread in new habitats. Invasive parasites are subject to these same conditions, though the effects may be mediated through their hosts. Here, I use an invasive snail and its trematode parasites to quantify the effects of desiccation on survival to better understand how processes of invasion play out in host-parasite systems. The faucet …

Tick Lipocalin Triggers Mammalian Igfbp-3-Mediated Apoptosis In Macrophages And Keratinocytes, Krittika Nandy, P. P. Mahesh, Lichao Liu, Daniel E. Sonenshine, Hameeda Sultana, Girish Neelakanta

Biological Sciences Faculty Publications

Ticks secrete several molecules, including lipocalins, in their saliva during blood feeding on a vertebrate host. In this study, we provide novel evidence on the role of Ornithodoros turicata americanus tick lipocalin (Otlip) in modulating cytokine expression and in triggering apoptosis in mammalian macrophages and keratinocytes. The cytokine array analysis revealed significantly increased secretion of insulin-like growth factor-binding protein 3 (IGFBP3) from murine macrophage cell line upon treatment with recombinant Otlip protein (rGST-Otlip) when compared to the secretion noted from cells treated with a control protein (rGST). Similar observation with cytokine protein array analysis was noted when murine macrophages were …

Advancing Trypanosoma Cruzi N-Myristoyltransferase As A Drug Target For Chagas Disease Through In Silico Discovery And Biochemical Evaluation, Diana Citlali González García

Open Access Theses & Dissertations

Chagas disease remains one of the most persistent and neglected parasitic infections in the Americas, advancing silently through the intracellular replication of Trypanosoma cruzi amastigotes and the invasive spread of trypomastigotes. The survival of the parasite is critically reliant on protein N-myristoylation, a lipid modification catalyzed by N-myristoyltransferase (NMT). This dissertation aims to advance beyond prior studies by systematically investigating NMT inhibition across multiple biological levels, spanning from the characterization of the purified enzyme, through cellular infection models, to the global proteomic remodeling induced within the parasite, thereby evaluating TcNMT as a potential therapeutic vulnerability in T.cruzi.Recombinant TcNMT was expressed, …

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 …

Ecoimmunology Of Dirty Physella Acuta Snails, Kevin Arthur Mcquirk

Biology ETDs

Research on Physella acuta, an invasive freshwater snail, reveals insights into its parasitology, fitness, and molecular biology. Morphological and molecular analyses revealed two distinct mitogenomic lineages, local (B) and invasive (A) strains of native P. acuta, both having comparable trematode infection rates, suggesting that the low infection rates observed from A in invaded regions result from "enemy release" rather than immune incompatibility. Fitness assessments showed that while lineages A and B performed similarly under laboratory conditions, rewilding experiments revealed significantly higher fitness in lineage A. Transcriptomic profiling supported these differences, with A snails showing greater immune-related gene expression and …

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 …

Parasitic Effects Of Amoebidium Appalachense On Daphnia Magna Heart Rate, Hopping Frequency, And Metabolic Rate, Vanessa Wise

Honors Program: Senior Projects (Public)

Daphnia magna are a crustacean that inhabits multiple different types of freshwater ecosystems and thus is plays a part in many different types of interspecies interactions, one of which is parasitism. Amoebidium appalachense is a Mesomycetozoean parasite of aquatic arthropods that colonizes the antenna of D. magna. Previous research has shown that A. appalachense infection will reduce the fecundity and increase mortality rate of D. magna but how it causes these effects is unknown. To determine if A. appalachense causes these effects on D. magna by either stealing nutrients inside the D. magna like a tick or by compromising …

Characterizing Malaria Infections In Caribbean Lizards: Parasite Niche Expansion & Host Response, Sarah J. Pangburn

Dissertations, Theses, and Capstone Projects

Malaria is historically one of the most severe parasitic human diseases and is still responsible for over half a million deaths annually. Plasmodium species, the causative agents of malaria, are often characterized by two hallmark features of their asexual stages: the invasion of vertebrate red blood cells and the presence of hemozoin pigment as a byproduct of host hemoglobin digestion. Despite their evolutionary relatedness to mammalian Plasmodium, wildlife malaria parasites are understudied, leaving their vast genetic diversity to be explored. Lizard-infective malaria parasites, for example, include over 100 species of Plasmodium and present a diverse array of phenotypes, some …

Developmental Regulation Of Corazonin, Eclosion Hormone, And Bursicon Messages And Rnai Suppression Of Corazonin In Adult Female American Dog Ticks, Dermacentor Variabilis, Anirudh Dhammi, Brooke Bissinger, Loganathan Ponnusamy, Daniel E. Sonenshine, R. Michael Roe

Biological Sciences Faculty Publications

The insect molting process is critical to growth and development and is regulated in part by the neuropeptides corazonin, eclosion hormone, and α and β bursicon. We found messages in a synganglion transcriptome from adult, female American dog ticks, Dermacentor variabilis (that do not molt), with a high similarity to the larval insect neuropeptides that control molting. The phylogenetic analysis of the tick putative neuropeptides compared to other arthropods is discussed in detail. The relative gene expression of these peptides was determined by quantitative PCR during the following adult developmental stages: (i) virgin, unfed 0–24 h after entering the adult …

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 …

Toxin-Like Proteins In The Venom Of Drosophila Parasitoids, Lady V. Cardenas

Dissertations and Theses

The figitid parasitoid wasps of Drosophila are gaining importance in agriculture due to their ability to kill the resilient soft-fruit pest Drosophila suzukii. Their success and infection strategies vary, and the mechanisms underlying these differences are largely unknown. Some of their venom proteins have been shown to be important in suppressing host defense. Here, we report that Ganaspis brasiliensis, a parasitoid of D. suzukii survives well on Drosophila yakuba, a host species with a strong cellular immunity, and infected flies are unable to mount a strong immune response. To predict possible toxin-like proteins in Ganaspis venoms that might suppress cellular …

Tick Responses To Diverse Chemical Attractants To Enhance Tick Surveillance Methods' Efficacy, Pamela Kelman, Tyler Chavers, Emily Owens Pickle, Daniel Sonenshine, Melissa S. Nolan, Holly Gaff

Biological Sciences Faculty Publications

Amblyomma maculatum Koch (Acari: Ixodidae), Ixodes scapularis Say, and Dermacentor variabilis Say are three hard-bodied ticks responsible for vectoring pathogens that cause most human tick-borne diseases in the United States of America (USA). Tick surveillance is critical to elucidate high-risk areas for targeted vector control and public health interventions. Despite tick-borne diseases having a higher annual incidence compared to mosquito-borne diseases in the USA, tick traps used for surveillance are grossly under-developed compared to the suite of sophisticated mosquito traps available on the commercial market. This study sought to identify potential prospective tick trap improvements by evaluating the relative attraction …

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 …

Helminth Parasites Of Galápagos Mammals: A New Cestode Of The Genus Raillietina From The Endemic Rice Rat Nesoryzomys Swarthi And A Summary Of Parasites From Both Endemic And Invasive Rodents, Scott Lyell Gardner, Emma K. Chesley, Michael C. Friedle, Altangerel Tsogtsaikhan Dursahinhan

Scott L. Gardner Publications

In this first report of endoparasites from endemic land-mammals of the Galápagos Islands, we describe a new species of cestode of the genus Raillietina (Cyclophyllidea: Davaineidae) from a species of Nesoryzomys and summarize the extent of helminth parasitism in both oryzomyine endemics and introduced species of Rattus. Up to the current time, no helminth parasites have been reported from rodents of the Galápagos, and little work has yet been done describing and synthesizing Galápagos parasite diversity. In historical times, several species of autochthonous rodents have occupied the islands including: Nesoryzomys narboroughi Heller 1904, N. fernandinae Hutterer and Hirsch …

Description Of All Stages Of A New Tick Species From California Haemaphysalis Vespertina (Acari: Ixodidae), With Redescription Of H. Leporispalustris Packard, 1869 Adults And Phylogenetic Relationships Among Related U.S. Taxa, Andrea Egizi, Santiago Nava, Angie Nakano, Megan E. M. Saunders, Lauren P. Maestas, Autumn D. Angelus, Bruce Noden, Robyn M. Nadolny, Waheed I. Bajwa, Charles Lubelcyzk, Chanakya R. Bhosale, Susan Paskewitz, Holly D. Gaff, Lorenza Beati

Biological Sciences Faculty Publications

All active stages of Haemaphysalis vespertina sp. nov. (Acari: Ixodidae), a tick previously identified as H. leporispalustris Packard, 1869, are described from specimens collected on the vegetation and from leporids in California and Oregon. The adults of H. leporispalustris Packard, 1969 are redescribed based on type material. Adults of the two species can be distinguished by their overall size, the dorsal shape of palpal segment II, the number and shape of dorsal and ventral setae on palpal segment II, the number of spurs on coxae II, the length of setae on scutum, legs and coxae, and the pattern of scutal …

Emotional Response In Working Memory Of Individuals With Latent Toxoplasmosis, Antonella Quimbayo

All HCAS Student Capstones, Theses, and Dissertations

Toxoplasma gondii is a prevalent parasite that infects about 30% of the world population. House cats and other felids serve as definitive hosts and acquire Toxoplasma by consuming infected prey, which are intermediate hosts. This includes rats and avians, but also large mammals such as wolves and deer. Toxoplasma gondii is known to manipulate prey behavior to enhance its transmission. For example, infected rodents demonstrates attraction to and curiosity around cat urine. Wolves infected with Toxoplasma were 11 times more likely to disperse from their pack and start a new pack. The manipulation of intermediate host behavior observed in rodents …

The Role Of Southern Red-Backed Voles, Myodes Gapperi, And Peromyscus Mice In The Enzootic Maintenance Of Lyme Disease Spirochetes In North Dakota, Usa, Michael W. Dougherty, Nathan M. Russart, Robert A. Gaultney, Emily Marie Gisi, Haley M. Cooper, Lindsey R. Kallis, Catherine A. Brissette, Jefferson A. Vaughan

Biology Faculty Publications

Lyme disease has expanded into the Great Plains of the USA. To investigate local enzootic transmission, small mammals were trapped in two forested tracts in northeastern North Dakota during 2012 and 2013. Peromyscus mice and southern red-backed voles, Myodes gapperi, comprised over 90% of all mammals captured. One site was dominated by Peromyscus (79% of 100 mammals captured). At the other site, M. gapperi (59% of 107 mammals captured) was more abundant than Peromyscus (36%). Immature stages of two tick species parasitized small mammals: Dermacentor variabilis and Ixodes scapularis. Larval I. scapularis ectoparasitism was significantly higher on Peromyscus (81% …

New Insights Into T Lymphocyte-Mediated Immunity To Toxoplasma Gondii, Claire Marie Doherty

Biology ETDs

With nearly a third of the global population infected with the protozoan, Toxoplasma gondii, this parasite sits at a unique, immune-mediated interface of health and disease. In healthy individuals, Toxoplasma results in a chronic yet asymptomatic infection of the central nervous system. This quiescent infection is the result of parasite exploitation of host immune barriers, yet Toxoplasma can quickly become an opportunistic pathogen when immunity is disrupted by illness or immunosuppressive therapies. During the HIV-AIDS pandemic, it was observed that once latent Toxoplasma infections became the cause of severe, even fatal, disease in the absence of an intact T …

Natural Enemies Of Varroa Destructor Identified From Eastern North America Honey Bee Colonies: A Biological Survey Of Candidates For Mite Control From Maryland, Usa, Francisco Posada-Flórez, Daniel Sonenshine, Jay Evans, Dawn Boncristiani, Monica Pava-Ripoll, Steven Cook

Biological Sciences Faculty Publications

A survey was conducted of microbes and arthropods associated with Varroa destructor (Acari: Varroidae) mites (hereafter, Varroa) collected from honey bee colonies in Maryland, USA. Live Varroa were challenged with samples of both microbes and arthropods and assessed for their potential as biocontrol agents against the mites. To our knowledge, this is the first survey of natural enemies of Varroa conducted in North American honey bee colonies. The survey revealed 21 fungi, 25 bacteria, one nematode, and 8 arthropod species associated with Varroa in honey bee colonies, and from challenge assays using 11 of these, including 4 species of …

The Effect Of Triaenophorus Crassus On The Condition Of Coregonus Artedi, Alexander Surma

Journal of Earth and Life Science

Cisco Coregonus artedi is, historically, the largest commercial fishery in the Great Lakes. The species is also important to commercial and recreational fisheries in inland lakes. Tapeworm Triaenophorus crassus larvae embed themselves into the flesh of Ciscoes, rendering the fish unmarketable to humans. Triaenophorus crassus is common in inland waters such as Leech Lake and Cass Lake, MN. One Canadian researcher has suggested that the parasite negatively affects the growth and weight of Ciscoes. Poor condition can reduce fecundity, leading to lower recruitment rates. This would mean a detrimental impact on not only individual fish, but the health of …

Human-Bat Interactions In A Disease Emergence Hotspot: Implications For Human Health And Bat Conservation, Reilly Tempest Jackson

Graduate Theses and Dissertations

Bats are an ecologically important taxon that can host zoonotic pathogens. Globally, many bat species are synanthropic and live closely with humans, often roosting in man-made structures. The spatial overlap between humans and bats creates opportunities for human-bat contact, which can lead to human exposure to bat-borne pathogens and conflicts that cause bat mortality. Despite this risk, little is known about the drivers and characteristics of these human-bat interactions in buildings and work is needed to understand this aspect of the wildlife-urban interface. In Chapter I, I present a literature review that identifies the geographic and taxonomic trends in reported …

Newer Surveillance Data Extends Our Understanding Of The Niche Of Rickettsia Montanensis (Rickettsiales: Rickettsiaceae) Infection Of The American Dog Tick (Acari: Ixodidae) In The United States, Catherine A. Lippi, Holly D. Gaff, Robyn M. Nadolny, Sadie J. Ryan

Biological Sciences Faculty Publications

Background: Understanding the geographic distribution of Rickettsia montanensis infections in Dermacentor variabilis is important for tick-borne disease management in the United States, as both a tick-borne agent of interest and a potential confounder in surveillance of other rickettsial diseases. Two previous studies modeled niche suitability for D. variabilis with and without R. montanensis, from 2002-2012, indicating that the D. variabilis niche overestimates the infected niche. This study updates these, adding data since 2012.

Methods: Newer surveillance and testing data were used to update Species Distribution Models (SDMs) of D. variabilis, and R. montanensis infected D. variabilis, in …

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 …

Promiscuous Feeding Across Multiple Honey Bee Hosts Amplifies The Vectorial Capacity Of Varroa Destructor, Zachary S. Lamas, Serhat Solmaz, Eugene V. Ryabov, Joseph Mowery, Matthew Heermann, Daniel Sonenshine, Jay D. Evans, David J. Hawthorne

Biological Sciences Faculty Publications

Varroa destructor is a cosmopolitan pest and leading cause of colony loss of the European honey bee. Historically described as a competent vector of honey bee viruses, this arthropod vector is the cause of a global pandemic of Deformed wing virus, now endemic in honeybee populations in all Varroa-infested regions. Our work shows that viral spread is driven by Varroa actively switching from one adult bee to another as they feed. Assays using fluorescent microspheres were used to indicate the movement of fluids in both directions between host and vector when Varroa feed. Therefore, Varroa could be in either …

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 …

Corrigendum: Characterization Of A Novel Transitional Group Rickettsia Species (Rickettsia Tillamookensis Sp. Nov.) From The Western Black-Legged Tick, Ixodes Pacificus, David T. Gauthier, Sandor E. Karpathy, Stephanie L. Grizzard, Dhwani Batra, Lori A. Rowe, Christopher D. Paddock

Biological Sciences Faculty Publications

No abstract provided.