Parasitology Commons^™

The Biochemical Assessment Of Two Secreted Acid Phosphatases From Leishmania Tarentolae, Their Response To Electric Fields, Glycosidase Incubation, And / Or Vanadium, Benjamin M. Dorsey

Theses and Dissertations

Leishmaniasis, as defined by the Center for Disease Control and Prevention, is a neglected tropical disease with 1.6 million new cases reported each year. However, there is yet to be safe, effective, and affordable treatments provided to those affected by this disease1. Still underappreciated as a potential pharmaceutical targets, especially for cutaneous leishmaniasis infections, are the two isozymes of secreted acid phosphatase (SAP); secreted acid phosphatase 1 (SAP1) and secreted acid phosphatase 2 (SAP2). These enzymes are involved in the survival of the parasite in the sand fly vector, and the prevention of host macrophages from forming parasitophorous vacuole and …

Molecular And Functional Analysis Of The Pixb Gene In Xenorhabdus Nematophila, John Lucas

Theses and Dissertations

Xenorhabdus nematophila and the entomopathogenic nematode Steinernema carpocapsae form a mutualistic relationship facilitating the infection, death and consumption of an insect host. The infective juvenile (IJ) form of S. carpocapsae invades the insect host through natural openings and proceeds to the hemocoel where exposure to hemolymph stimulates the release of X. nematophila from the anterior vesicle. Excreted X. nematophila releases immunosuppressive compounds and insect toxins into the insect hemolymph that facilitates death of the host. As X. nematophila reaches high cell density it secretes exoenzymes that degrade insect tissues and produces antibiotics that reduce microbial competition. S. carpocapsae utilizes the …

Inhibitory Effects Of Unique Sulfonamides On Leishmania Tarentolae And Potential Pathway Of Inhibition, Jade M. Katinas

Theses and Dissertations

Leishmaniasis is an endemic disease caused by the protozoan parasite Leishmania. Current treatments for the parasite are limited by cost, availability, and drug resistance as the worldwide occurrence of leishmaniasis continues to be more prevalent. Sulfonamides are a class of compounds with medicinal properties that have been used to treat bacterial and parasitic diseases via various pathways. In this study, newly synthesized, unique structural analogs of sulfonamide compounds were assessed for their impact on Leishmania cell viability and potential pathways for inhibition were evaluated. Leishmania tarentolae (ATCC Strain 30143) axenic promastigote cells were grown in BHI medium and treated with …

Genomic Comparisons And Genome Architecture Of Divergent Trypanosoma Species, Katie Bradwell

Theses and Dissertations

Virulent Trypanosoma cruzi, and the non-pathogenic Trypanosoma conorhini and Trypanosoma rangeli are protozoan parasites with divergent lifestyles. T. cruzi and T. rangeli are endemic to Latin America, whereas T. conorhini is tropicopolitan. Reduviid bug vectors spread these parasites to mammalian hosts, within which T. rangeli and T. conorhini replicate extracellularly, while T. cruzi has intracellular stages. Firstly, this work compares the genomes of these parasites to understand their differing phenotypes. Secondly, genome architecture of T. cruzi is examined to address the effect of a complex hybridization history, polycistronic transcription, and genome plasticity on this organism, and study its highly …

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

Theses and Dissertations

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

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

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

Theses and Dissertations

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

Endoparasites Of Cats In Two Central Utah Communities, Thomas W. Sawyer

Theses and Dissertations

A survey of the endoparasites of 100 stray cats in central Utah was conducted. Each cat was euthanized, and the entire alimentary tract, gall bladder, bile duct, heart, respiratory and excretory systems were excised and examined for endoparasites. Fecal samples were examined by a sugar flotation technique. Parasites identified and number of cats infected were: Isospora felis 5; I. rivolta, 4; Dipylidium caninum, 1; Hydatigera taeniaformis, 10; Toxocara mystax, 43; and Physaloptera sp., 2. One ectoparasite, Cheyletiella parasitivorax, was identified in the feces of 4 cats. Dipylidium caninum and T. mystax are known to cause accidental infection in humans and …

Efficacy Of Bunamidine Hydrochloride Against Immature And Mature Stages Of Echinococcus Granulosus, Lauritz A. Jensen

Theses and Dissertations

A study was conducted to determine the efficacy of bunamidine hydrochloride against the immature and mature stages of Echinococcus granulosus found in Utah. Twenty-seven dogs were obtained from local animal shelters and experimentally infected with the parasite. The drug was given at dosage levels of 25 mg/kg to 50 mg/kg of bodyweight. It was from 85.9 to 98.8% effective against the immature stage, and 100% effective against the adult stage. The results suggest that this drug can feasibly be used under field conditions where hydatid disease is endemic.

Cinemicrography Of Selected Parasites Of Fishes And Of Free-Living Stages Of Haemonchus Contortus, Stephen Homer Hilton

Theses and Dissertations

Two 16 mm color films were made to help fill a general need for instructional motion pictures in the area of Parasitology. One film "Haemonchus contortus, a Sheep Stomach Worm," deals with a nematode parasite of sheep, showing all stages of its external development and including a time-lapse sequence of the embryonation of the egg. The other film, "Some Parasites of Freshwater Fishes," shows six parasites; Ichthyophthirius multifiliis, Cotylurus erraticus, Dactylogyrus sp., Lernaea cyprinacea, Trichodina sp., and Diplostomum spathaceum for the first time in motion pictures. The films were photographed through a Wild dissecting scope and a Reichert Universal Camera …

The Effects Of Temperature On The Oocysts Of Isospora Canis, Ray Loveless

Theses and Dissertations

Oocysts of Isospora canis, an important protozoan parasite of dogs, must sporulate in the external environment in order to become infective. To determine the tolerance of these oocysts to different temperatures, oocysts ware collected from freshly passed feces, cleaned, and subsequently stored in unsporulated, partially sporulated, and completely sporulated conditions at temperatures ranging from +50 C to -50 C. Observations on survival for each group were determined periodically thereafter at intervals up to 64 days. The rate of sporulation was followed at 6 hr intervals for temperatures of 20, 25, 30, and 38 C. Completely sporulated oocysts ware more resistant …

The Effect Of Haloxon And Thiabendazole On The Free-Living Stages Of Haemonchus Contortus, Gary Mccallister

Theses and Dissertations

This study was undertaken to determine the effect of thiabendazole and haloxon on the free-living stages of Haemonchus contortus and to determine the suitability of the free-living stages for their use in primary drug evaluation for chemotherapy or for chemical control of free-living stages. Cleaned unembryonated ova, embryonated ova, first-, second-, third-, and exsheathed third-stage larvae were exposed to suspensions of 5.0%, 1.0%, 0.5%, 0.25%, 0.12%, 0.05%, and water soluble concentrations of each drug for exposure times of 0.25, 0.50, 1.0, 2.0, 4.0, 8.0, and 16.0 hours at pH 7.0 and 25° C. Survival was assessed by observing any subsequent …

A Proposed Mechanism Of Action For In Vitro Excystation Of Two Species Of Coccidia, William Ronald Jolley

Theses and Dissertations

Excystation of coccidian oocysts is accomplished in vitro by altering wall permeability with CO2 and a reducing agent, then activating the enclosed sporozoites with a solution of trypsin and bile. Elucidation of the mechanism of action of the CO2-reducing agent treatment was the basic intent of this study. Oocysts of Eimeria stiedae (rabbit) and E. tenella (chicken) were tested for the presence of an excystation-associated enzyme by incubating sporulated oocysts in fluids extracted from variously treated oocysts, and by carbon-14 labelling; the effect of CO2 -reducing agent treatment on oocyst walls was investigated by titration with acid or base for …

The Effects Of Different Gases On Excystation Of Coccidian Oocysts, James B. Jensen

Theses and Dissertations

Excystation of coccidian oocysts is a diphasic process where CO2 and suitable reducing agents cause changes in oocyst wall permeability (phase I) allowing the entrance of trypsin and bile which activate the sporozoites (phase II). This project was an indirect study of the mechanism of CO2 action by the substitution of NO, NO2, N2O, H2S, SO2 , CH4, NH3 and 8M urea in place of CO2. Changes in oocyst wall permeability of Eimeria stiedae, E. bovis and E. tenella were determined by incubation with the reagents and cysteine HCl followed by treatment with trypsin and bile to initiate activation of …

The Effects Of Temperatures And Chemicals On The Oocysts Of Eimeria Stiedae, Charles Larry Keehner

Theses and Dissertations

A study was made of the effects of temperatures and chemicals on the unsporulated and sporulated oocysts of Eimeria stiedae. In general, oocysts were affected by temperatures lower than -10 C and above +39 C, while normal development occurred between these temperatures. Unsporulated oocysts were more tolerant to temperature extremes, as they survived up to 8 days at 39 C and 12 days at -28 C. Sporulated oocysts were killed after 24 hours storage at 39 C and 4 days at -28 C. Oocyst resistance to low temperatures was not improved if unsporulated and sporulated oocysts were conditioned before and …

The Reproductive Biology Of The Leech Helobdella Stagnalis (Linnaeus) In Utah Lake, David L. Tillman

Theses and Dissertations

The reproductive biology of the brooding leech Helobdella stagnalis (Linnaeus) in Utah Lake was studied for an 18 month period from June 1970 to December 1971. In determining the annual reproductive cycle, the number of adult leeches carrying eggs or young were counted at weekly intervals during the reproductive season and monthly during the rest of the year. Gonadal staging data from histological sections were correlated with the field collection data. It was found that two broods of young were produced by the adult animals during the reproductive season. Continuous water temperatures were recorded at the study site throughout the …

Post-Mortem Examination Of Cattle And Sheep For Parasitic Helminths, Phil Duke Wright

Theses and Dissertations

A survey of helminth parasites of sheep and cattle was conducted to determine the incidence and distribution of these parasites that could be detected by post-mortem examination. Animals were obtained from local abattoirs within the valley, and the viscera were examined for the presence of helminth parasites. Parasites identifies from sheep in order of highest incidence were: Haemonchus contorus, Ostertagia cicumcinta, Chabertia ovina, Nematodirus spathiger, Trichostongylus colubriformis, Thysanosoma actinioides, Trichuris ovis, N. filicollis, Echinococcus granulosus, Strongyloides papillosus, O. ostertagi, Cooperia oncophora, Cysticercus tenuicollis, Fasciola hepatica, Oesophagostomum venulosum, Moniezia expansa, and M. benedieni. Those recovered from cattle in order of highest …

The Effect Of The Parasite Hymenolepis Diminuta On Iodine Economy In The Rat, David Gourdon Holmes

Theses and Dissertations

A balance of iodine within the rats is important for the maintenance of normal thyroid function. Because of Hymenolepis d[imi]nuta's affinity for certain nutrients, it may upset norma[l] iodine balance in the rat. To determine this, tapeworm-infected and non-infected rats were given 125Iodide orally and the percent uptake of iodide by the thyroid and the amount of radioac[tiv]ity in the tapeworms was determined. The percent distribution of the radio-iodinated compounds in the thyroid, tapeworms and feces was also determined. These procedures were repeated except 125Thyroxine was administered orally. There was a decrease in percent iod[id]e uptake by thyroids of tapeworm-infected …

A Survey Of The Helminth Parasites And Coccidia Of Cattle And Sheep In Utah Valley, Joseph Carl Fox

Theses and Dissertations

A survey of gastro-intestinal parasites in cattle and sheep in Utah Valley was conducted. Cattle in the valley were not seriously parasitized by helminths, whereas sheep usually had heavy helminth infections. Ten genera of helminths and 8 species of coccidia were identified in cattle in the valley, and 14 genera of helminths and 8 species of coccidia were identified in sheep. In conjunction with the survey, meteorologic studies were conducted May through September, 1909, to ascertain the effects which irrigation had upon micro-environments on grass pastures in relation to the development of free-Iiving stages of gastro-intestinal nematodes of ruminants. The …

Ticks Of The Genus Haemaphysalis In The Western United States, Joe M. Merino

Theses and Dissertations

Two species of Haemaphysalis occurring in the western United States were studied with respect to geographical distribution, seasonal occurrence, host-parasite association and external anatomy and morphology. H. leporispalustris is widely distributed in the west. Abundant records for some states are lacking and should be provided to extend the knowledge of this tick's distribution.

A Morphological Study Of Some Larval Ticks Of The Genus Dermacentor With Emphasis On Structures Of Possible Taxonomic Importance, Richard Grant Robertson

Theses and Dissertations

This study was undertaken to evaluate and determine morphological characteristics which might prove valuable in the identification of the larvae of the following species of ticks of the genus Dermacentor Koch: D. albipictus Packard, D. andersoni Stiles, D. hunteri Bishop, D. parumapertus Neuman, and D. variabilis Say. A taxonomic key for the identification of all of the Canadian and United States species of the larvae of the genus Dermacentor Koch cannot be constructed until specimens of D. halli and D. occidentalis have been examined. However, the followng conclusions were reached regarding the species studied: 1. Position of setae is of …

Identification Of Larval Ticks Of The Genus Ixodes Known To Occur In Utah, Leland D. White

Theses and Dissertations

The purpose of this study is to present an analysis and key to the larvae of the nine species of Ixodes known to occur in Utah. These are I. kingi, I. muris, I. texanus, I. pacificus, I. spinipalpis, I. marmotae, I. ochotonoe, I angustus, and I. sculptus. Larvae from the first five of these nine species used in this study were reared in the laboratory by worked cited in the secion on Analysis of Species. those of the remaining four were identified on the basis of their presence with identifiable numphal and adult forms. Host specificity, although certainly variable with …

Oviposition Habits Of The Tick Dermacentor Parumapertus Neumann And Factors Influencing Egg Development, Clive D. Jorgensen

Theses and Dissertations

This paper includes data concerning the influence of relative humidity, temperature, and percentage of engorgement on the pre-oviposition period, oviposition period, post-oviposition period, and incubation period of the tick Dermacentor parumapertus Neumann. The influence of the percentage of engorgement on the oviposition period, oviposition rate, and egg number is considered. Data on the disposition and number of eggs in nature are discussed.