Open Access. Powered by Scholars. Published by Universities.®

Parasitology Commons™

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 14 of 14

Full-Text Articles in Parasitology

Potency Of Novel Anti-Toxoplasmic Compounds, Matthias Walters May 2023

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 …


Investigating Novel Chemotherapeutics Against The Parasite Toxoplasma Gondii, Braydon Dreher May 2023

Investigating Novel Chemotherapeutics Against The Parasite Toxoplasma Gondii, Braydon Dreher

Theses/Capstones/Creative Projects

Toxoplasma gondii, an intracellular protozoan, is a globally prevalent parasite due to the infectivity of T. gondii with nearly 2.5 billion people affected worldwide. Toxoplasma gondii can cause toxoplasmosis, which is a disease acquired through the consumption of undercooked meat or found in the feces of felines, and often leads to profound neuropathology and potentially death. Currently, acute toxoplasmosis is treated with pyrimethamine and sulfadiazine, which is a combination of an antiprotozoal and a sulfonamide. This combination of drugs directly targets the acute stage of infection but has failed to eliminate or impact the chronic carriage of bradyzoites while …


Investigating Granulopoiesis Of Neutrophils From Myeloblasts In The Bone Marrow Post Novel Anti-Schistosoma Compound Treatment, Sarah Alsuleiman, Paul Davis Aug 2022

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 …


A Mechanistic Study On The Immunological Effects Of A Novel Anti-Schistosomal Compound, Caleb M. Sandall, Paul H. Davis May 2022

A Mechanistic Study On The Immunological Effects Of A Novel Anti-Schistosomal Compound, Caleb M. Sandall, Paul H. Davis

Theses/Capstones/Creative Projects

Schistosomiasis is a condition caused by a parasitic worm infection that is one of the primary neglected tropical diseases. It infects approximately 250 million people every year, and it causes the second largest economic impact from any parasitic disease. There exists a treatment for Schistosomiasis; however, it is ineffective against the juvenile stages of the worm. A novel drug has been developed that has been illustrated to have efficacy against all stages of worm infection. However, before this drug can be utilized, its method of action must be determined. Preliminary single cell transcriptomic data from our lab suggests that our …


Exploring Anti-Schistosoma Analog Sa01, Sarah Alsuleiman Mar 2021

Exploring Anti-Schistosoma Analog Sa01, Sarah Alsuleiman

UNO Student Research and Creative Activity Fair

Schistosomiasis is a waterborne parasitic worm infection able to infect in the larval stage through direct skin penetration. This disease affects approximately 270 million people worldwide and is widespread in tropical as well as subtropical regions with higher distribution in areas lacking sufficient sanitation and safe drinking water. 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. Furthermore, Schistosoma is developing resistance to this drug as reduced efficacy has been noted. As a result, …


Elucidating The Mechanism Of Action Of Experimental Compound Sw33 In Toxoplasma Gondii, Sean Watson May 2019

Elucidating The Mechanism Of Action Of Experimental Compound Sw33 In Toxoplasma Gondii, Sean Watson

Theses/Capstones/Creative Projects

In recent years, antimicrobial drug resistance has become widespread and thus triggered an ever-growing need for the development of new, efficacious drug treatments. As an antimicrobial drug is developed, its mechanism of action is often identified before it becomes a potential candidate for clinical use. One potential method for identifying mechanism of action is chemical mutagenesis, in which induction of drug-resistant populations is followed by whole-genome sequencing of several clonal isolates. The subsequent observation of identical point mutations in the same gene across multiple drug-resistant populations can indicate a likely molecular target. However, this technique lacks the capacity to facilitate …


Investigation Of Bradyzoite Differentiation Initiation In Toxoplasma Gondii, Harim I. Won, Paul H. Davis Ph.D. May 2018

Investigation Of Bradyzoite Differentiation Initiation In Toxoplasma Gondii, Harim I. Won, Paul H. Davis Ph.D.

Theses/Capstones/Creative Projects

Like other eukaryotic organisms, Toxoplasma gondii promoters feature both constitutive and life-stage regulated cis-elements. Using a transcriptomic microarray approach, a cluster of transcripts upregulated early during bradyzoite differentiation was identified. Computational analysis of the promoter regions of these “up-early” transcripts identified a shared upstream consensus motif, a putative transcription factor binding site. Using a dual luciferase assay adapted for recombinational cloning and reporter gene quantification by qPCR, we demonstrate developmental stage-specific expression of the luciferase reporter gene inserted downstream of the transcription factor binding site. The shared consensus motif was found to be an autonomous cis-element by conversion …


Towards A Mechanism Of Action Of An Antischistosomal Drug: Measuring Granulocytic Activity, Samantha Sack Mar 2018

Towards A Mechanism Of Action Of An Antischistosomal Drug: Measuring Granulocytic Activity, Samantha Sack

UNO Student Research and Creative Activity Fair

Schistosomiasis is a neglected tropical disease caused by a family of schistosome parasites which leads to vital organ damage. Praziquantel (PZ) is the only available treatment, but it is effective only against the adult worm. Partner labs have tested an antischistosomal drug which has been shown to have a higher efficacy against both juvenile and mature parasites in mice and monkeys compared to PZ. This effectiveness does not transfer to in vitro experiments; it kills the parasite outside of its host only at extremely high concentrations. This indicates that its efficacy is host-dependent, but the mechanism by which it functions …


The Evaluation Of Carbon Dioxide-Independent Media For Toxoplasma Gondii Growth, Matthew C. Martens Mar 2017

The Evaluation Of Carbon Dioxide-Independent Media For Toxoplasma Gondii Growth, Matthew C. Martens

UNO Student Research and Creative Activity Fair

Toxoplasma gondii is a human pathogen that plays a role as the causative agent of toxoplasmosis, a disease that produces many deleterious effects for immunocompromised individuals and infants. Current research involving this intracellular parasite requires the use and continues maintenance of costly cell incubators attached to bulky carbon dioxide canisters. To reduce laboratory costs and space requirements, we, therefore, propose a novel procedure by which human foreskin fibroblasts, as well as Toxoplasma gondii tachyzoites, may be grown in a commercially available carbon dioxide-independent media. Growth assays utilizing resazurin dye or relative fluorescence from parasites modified with a red fluorescent protein …


Alternative Life Cycle Strategies And Colonization Of Young Anurans By Gorgoderina Attenuata In Nebraska, Matthew G. Bolek, Scott D. Snyder, John J. Janovy Jr. Jun 2009

Alternative Life Cycle Strategies And Colonization Of Young Anurans By Gorgoderina Attenuata In Nebraska, Matthew G. Bolek, Scott D. Snyder, John J. Janovy Jr.

Biology Faculty Publications

Studies on life cycles and epizootiology of North American frog bladder flukes indicate that adult frogs become infected predominantly by ingesting tadpoles or other frogs that serve as second intermediate hosts for gorgoderid metacercariae. Other studies have indicated that newly metamorphosed frogs are rarely infected with these parasites because they are gape-limited predators that cannot feed on large intermediate hosts such as tadpoles and other frogs. We examined the role of potential intermediate hosts in the recruitment of the frog bladder fluke, Gorgoderina attenuata, to metamorphosed northern leopard frogs, Woodhouse’s toads, and bullfrogs from western Nebraska. We completed the …


Redescription Of The Frog Bladder Fluke Gorgoderina Attenuata From The Northern Leopard Frog, Rana Pipiens, Matthew G. Bolek, Scott D. Snyder, John J. Janovy Jr. Jun 2009

Redescription Of The Frog Bladder Fluke Gorgoderina Attenuata From The Northern Leopard Frog, Rana Pipiens, Matthew G. Bolek, Scott D. Snyder, John J. Janovy Jr.

Biology Faculty Publications

Morphological characters used to differentiate North American bladder flukes, Gorgoderina spp., are problematic and different authors use different morphological characteristics for distinguishing species. More importantly, no type specimens exist for four of the 12 North American species infecting anuran and caudatan hosts. A redescription of Gorgoderina attenuata (Stafford, 1902) Stafford, 1905 is based on new collections from 6 species of anurans from Arkansas, Nebraska, New York, and Wisconsin. Morphological comparisons between gravid G. attenuata recovered from bullfrogs and northern leopard frogs indicated statistically significant differences in 11 of 28 morphological characters examined. However, there was overlap among all of these …


Evolutionary Constraints On Population Structure: The Parasites Of Fundulus Zebrinus (Pisces: Cyprinodontidae) In The South Platte River Of Nebraska, John J. Janovy Jr., Scott D. Snyder, Richard E. Clopton Aug 1997

Evolutionary Constraints On Population Structure: The Parasites Of Fundulus Zebrinus (Pisces: Cyprinodontidae) In The South Platte River Of Nebraska, John J. Janovy Jr., Scott D. Snyder, Richard E. Clopton

Biology Faculty Publications

Population and community descriptor values (parasites per host, prevalence per parasite species, variance/mean ratios, species density, and diversity indices) for the 7-species parasite community of 61 relatively homogeneous samples of Fundulus zebrinus (Pisces: Cyprinodontidae) in the South Platte River of Nebraska, U.S.A., taken over a 14-yr period, are reported. South Platte River streamflow fluctuates over two orders of magnitude on several time scales-monthly, annually, and over multiple year wet-dry cycles. Relatively homogeneous sampling of a single host species with several parasite species provided a system that allowed assessment of the contribution of evolved parasite life cycles to population structure in …


Behavioral Basis Of Second Intermediate Host Specificity Among Four Species Of Haematoloechus (Digenea: Haematoloechidae), Scott D. Snyder, John J. Janovy Jr. Feb 1996

Behavioral Basis Of Second Intermediate Host Specificity Among Four Species Of Haematoloechus (Digenea: Haematoloechidae), Scott D. Snyder, John J. Janovy Jr.

Biology Faculty Publications

Cercarial behavior patterns were examined in four species of frog lung flukes (Haematoloechus spp.). Cercariae of Haematoloechus complexus, Haematoloechus medioplexus, Haematoloechus longiplexus, and Haematoloechus varioplexus were exposed to three species of experimental arthropods and an inanimate control. The number of cercariae attached to an experimental host at 5 min postexposure was recorded. Haematoloechus longiplexus and H. complexus cercariae attached to experimental hosts at higher rates than cercariae of H. medioplexus and H. varioplexus. Cercariae of H. longiplexus attached to experimental hosts in approximately the same numbers as H. complexus, but H. longiplexus penetrated only damselfly naiads, …


Second Intermediate Host-Specificity Of Haematoloechus Complexus And Haematoloechus Medioplexus (Digenea: Haematoloechidae), Scott D. Snyder, John J. Janovy Dec 1994

Second Intermediate Host-Specificity Of Haematoloechus Complexus And Haematoloechus Medioplexus (Digenea: Haematoloechidae), Scott D. Snyder, John J. Janovy

Biology Faculty Publications

Second intermediate host-specificity was examined for two species of the frog lung fluke genus Haematoloechus. Nine species of freshwater arthropods were exposed to cercariae of H. complexus and H. medioplexus. Metacercariae of H. complexus developed in all arthropod species used. Metacercariae of H. medioplexus developed only in anisopteran odonate naiads. This difference in host utilization may have epizootiological implications. The potential development of H. complexus in a greater number of arthropods than H. medioplexus may increase the chances of ingestion of H. complexus by an anuran host. The range of arthropods parasitized by H. complexus indicates that host-specificity …