DOCSLIB.ORG

Selective Effects of Paraherquamide on Ascaris Suum Nachr Subtypes

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Selective Effects of Paraherquamide on Ascaris Suum Nachr Subtypes Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1-1-2003 Selective effects of paraherquamide on Ascaris suum nAChR subtypes Hai Qian Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Recommended Citation Qian, Hai, "Selective effects of paraherquamide on Ascaris suum nAChR subtypes" (2003). Retrospective Theses and Dissertations. 19544. https://lib.dr.iastate.edu/rtd/19544 This Thesis is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. Selective effects of paraherquamide on Ascaris suum nAChR subtypes by Hai Qian A thesis submitted to the graduate faculty in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Major: Neuroscience Program of Study Committee: Richard Martin, Major Professor Alan Robertson Walter Hsu Tim Day Douglas Jones Iowa State University Ames, Iowa 2003 Copyright D Hai Qian, 2003. All rights reserved. 11 Graduate College Iowa State University This is to certify that the master's thesis of Hai Qian has met the thesis requirements of Iowa State University --, Signatures have been redacted for privacy 111 TABLE of CONTENTS LIST OF FIGURES vi LIST of TABLES Vlll ABSTRACT ix CHAPTER 1. GENERAL INTRCJDUCTIUN 1.1. Introduction 1 1.2. Thesis organization 1 CHAPTER 2. LITERATURE REVIEW 2.1. Parasites 3 2.1.1. Parasitic nematodes: ~iscaris suum and 14scaris lumbricordes 2.2. Nervous system of 14scaris 5 2.3. The somatic muscle cell of Ascaris 7 2.3.1. Belly 2.3.2. Arm 2.3.3. Spindle 2.3.4. Membrane potential of the muscle cell 2.3.5. Spontaneous electrical activity of the muscle cell 2.4. Neurotransmitters and pharmacology of the neuromuscular system 10 2.4.1. Acetylcholine 2.4.2. GABA 2.5. Anthelmintics: levamisole and paraherquamide 12 2.5.1. Levamisole 2.5.2. Paraherquamide 2.6. Structure of nicotinic acetylcholine receptors 14 2.6.1. The structure of Torpedo nACh receptors 2.6.2. Structural changes during ligand binding 1V 2.6.3. The amino acid sequences of Torpedo nicotinic acetylcholine receptors 2.7. Subunits of nicotinic acetylcholine receptors 20 2.7.1. The subunits of nAChRs in the nematode C. elegans a. Levamiso e receptors b. DEG-3-like c. ACR-8-like 2.7.2. The subunits of nAChRs in vertebrates 2.8. Pharmacological subtypes of nematode nAChRs 24 CHAPTER 3. MATERIALS AND METHODS 3.1. Collection and maintenance of ~4scaris suum 26 3.2. The vesicle preparation 26 3.3. Single-channel recording 28 3.3.1. Instruments a. Amplifier b . Digitizer c. Instrument setup 3.3.2. Electrodes 3.3.3. Measuring the pipette resistance 3.3.4. Reducing background noise 3.3.5. A giga-ohm seal 3.3.6. Recording ion channel currents 3.3.7. Application of paraherquamide 3.3.8. Storage of data 3.4. Data processing 3 3 3.4.1. Software tools 3.4.2. Event list s 3.4.3. Single-channel conductance 3.4.4 • Popen 3.4.5. Mean open time CHAPTER 4. SINGLE-CHANNEL CURRENTS FROM ASCARIS SUUM LEVAMISOLE-ACTIVATED RECEPTORS 4.1. The single-channel conductances show more than one level 3 9 4.2. The mean open time is correlative to the single-channel conductance 45 4.3. Discussion 48 CHAPTER 5. TAE SELECTIVE EFFECTS OF PARAHERQUAMIDE ON THE LEVAMISOLE-ACTIVATED RECEPTORS LOCATED ON ASCARIS SUUM MUSCLE CELLS 5.1. Paraherquamide is an antagonist of the nAChR located on Ascaris scum 50 muscle cells 5.2. The inhibitory effects of paraherquamide are selective on the nAChR 53 subtypes 5.3. Discussion 57 CHAPTER 6. GENERAL DISCUSSION 6.1. The mean level-Popen of the three nAChR subtypes and the %contribution 58 of each subtype to the whole cell current induced by 30 ~,M levamisole at +75 mV 6.2. Numbers of the three nAChR subtypes on Ascaris suum muscle cells 60 6.3 . Channel-Popen of the three nAChR subtypes 61 6.4. The paraherquamide effects on the whole cell currents 62 6.5. Do the conductance subtypes correspond to pharmacological subtypes? 62 CHAPTER 7. CONCLUSIONS 64 REFERENCES 66 ACKNOWLEDGEMENTS 76 V1 LIST OF FIGURES Figure 2.1. The life cycle of nematode Ascaris lumbricoides 4 Figure 2.2. The anterior part of the nervous system S Figure 2.3 . Transverse section of Ascaris 6 Figure 2.4. Diagram of the dorsal and ventral nerve cord in one segment of Ascaris 6 Figure 2.5. Schematic diagram of the muscle cell and the neuromuscular junction 8 Figure 2.6. An example of Spontaneous electrical activities recorded from the bag 9 region of Ascaris muscle cells Figure 2.7. Chemical structure of acetylcholine 11 Figure 2.8. Chemical structure of gamma-aminobutryic acid (GABA) 12 Figure 2.9. Chemical structure of levamisole 13 Figure 2.10. The chemical structure of the paraherquamide A 14 Figure 2.11. Diagram of the nicotinic acetylcholine receptor 16 Figure 2.12. The ACh binding of nAChRs in top view 17 Figure 2.13. The secondary structure of the nicotinic acetylcholine receptor subunit 17 Figure 2.14. The amino acid sequences of the Torpedo nAChR subunits 19 Figure 2.15. The diagram of the tree of the C. elegans nAChR subunits 21 Figure 3.1. Schematic diagram of the instrument setup 3 0 Figure 3.2. An example of the events list 34 Figure 3.3 . The Popen of the levamisole-activated receptor 3 6 Figure 4.1. The single-channel currents recorded at four different membrane 40 potentials Figure 4.2. The single-channel currents observed at +75 mV membrane potential on 41 a shorter time scale Figure 4.3. The amplitude histogram 41 Figure 4.4 . The I- T~ plot 42 Figure 4.5 . The histogram of collected conductances from 3 0 patches 44 Figure 4.6. The open dwell-time at +75 mV 45 Figure 4.7. The scatter plot of the mean open time vs. single-channel conductance 47 Figure 4.8. The mean open time for each conductance level 47 Vll Figure 4.9. Double-opening of single-channel current at +75 mV membrane 49 potential Figure S .1. The inhibitory effect of paraherquamide on the levamisole-activated single-channel currents of the ~4scaris suum nAChR 51 Figure 5.2. Paraherquamide reduces the patch-Popen of the levamisole-activated 52 receptor with aconcentration-dependant manner Figure 5.3. The selective effects of 1µM paraherquamide on the nAChR subtypes 54 Figure 5.4. The inhibitory effects of paraherquamide on the three subtypes 56 Figure 6.1. A model for calculating the contributions of the three subtypes nAChRs 60 to the transmembrane currents induced by 3 0 µM levamisole Vlll LIST OF TABLES Table 2.1. Hierarchy of the Ligand Gated Ion Channel 15 Table 3.1. Composition of solutions used in experiments 27 Table 4.1. The conductances and reversal potentials of the levamisole-activated 43 receptor Table 4.2. The mean open times at +75 mV 46 Table 5.1. The effects of 3µM paraherquamide on the conductance and the mean 53 open time Table 5.2. The effect of paraherquamide on the level-Pope s of the nAChR subtypes 5 5 Table 6.1. The level-Popen s observed from 30 patches 59 1X ABSTRACT Nematode parasites infest humans and animals causing morbidity and significant economic loss. Ascaris suum lives in the small intestine of the pig. Ascaris infestation of pigs can cause Ascariasis and poor growth rate. Another species, Ascaris lumbricoides infects humans. More than one billion people in the world suffer the Ascaris infestation (Crompton, 1984). Nicotinic anthelmintic compounds, which act on nematode nicotinic acetylcholine receptors (nAChRs), used to treat nematode infestation. However, the long-term repeated intake of one anthelmintic compound may cause the drug resistance. Robertson (1999) suggested that the resistance to anthelmintic compound levamisole may due to the loss of a levamisole-sensitive nAChR subtypes. Paraherquamide is a novel anthelmintic compound and is effective against strains of parasites that are resistant to the known broad-spectrum anthelmintic drugs (Shoop et al., 1990, 1991, 1992). The published data suggests that it behaves like a competitive antagonist of nematode nAChRs located on the nematode somatic musculature. In this research the effect of paraherquamide on the nematode Ascaris suum nAChRs was investigated at the single-channel level. Membrane vesicles were prepared from collagenase-treated Ascaris muscle flaps. The single-channel currents induced by 30 µM levamisole were recorded using inside-out patches isolated from the vesicles. The channels had conductances ranging from 18 pS to 52 pS. Paraherquamide was added to the bath chamber during recordings to give a final concentration of 0.3 -10 µM and its effects on the single-channel currents were monitored. Paraherquamide reduced the probability of channel being open (Popen) in a concentration-dependent manner. 1 µM paraherquamide selectively reduced the Popen values of the 45 pS channel; it had less effect on the Popen of the 3 5 pS channel, and the smallest effect on the 21 p S channel. This selectivity illustrates that the 21, 3 5 and 4 5 p S channels are pharmacologically distinct and suggests structural differences. The present study demonstrates that paraherquamide is an antagonist of the nAChRs located on the somatic musculature of parasitic nematodes and confirms at the single-channel level the selective effect of paraherquamide on the Ascaris nAChRs subtypes.
Load more

Recommended publications
  • Hybrid Ascaris Suum/Lumbricoides (Ascarididae) Infestation in a Pig
    Cent Eur J Public Health 2013; 21 (4): 224–226 HYBRID ASCARIS SUUM/LUMBRICOIDES (ASCARIDIDAE) INFESTATION IN A PIG FARMER: A RARE CASE OF ZOONOTIC ASCARIASIS Moreno Dutto1, Nicola Petrosillo2 1Department of Prevention, Local Health Unit, ASL CN1, Saluzzo (CN), Italy 2National Institute for Infectious Diseases “Lazzaro Spallanzani”, Rome, Italy SUMMARY We present a case of the 42 year old pig farmer from the province of Cuneo in Northwest Italy who was infected by the soil-transmitted nema- tode Ascaris sp. In November 2010 the patient found one worm in his stool, subsequently identified as female specimen of Ascaris sp. After a first anthelmintic treatment, another worm was found in his stool, that was later identified as male Ascaris sp. Blood tests prescribed by the patient’s family physician, as suggested by a parasitologist, found nothing abnormal. A chest x-ray was negative for Loeffler’s syndrome and an ultrasound of the abdomen was normal with no evidence of hepatic problems. The nematode collected from the patient was genetically characterized using the ribosomal nuclear marker ITS. The PCR-RFLP analysis showed a hybrid genotype, intermediate between A. suum/lumbricoides. It was subsequently ascertained that some pigs on the patient’s farm had A. suum infection; no other family member was infected. A cross- infestation from the pigs as source was the likely way of transmission. This conclusion is further warranted by the fact, that the patient is a confirmed nail-biter, a habit which facilitates oral-fecal transmission of parasites and pathogens. Key words: ascariasis, Ascaris suum, cross infection, pigs, zoonosis, hybrid genotype Address for correspondence: M.
    [Show full text]
  • High Heritability for Ascaris and Trichuris Infection Levels in Pigs
    Heredity (2009) 102, 357–364 & 2009 Macmillan Publishers Limited All rights reserved 0018-067X/09 $32.00 www.nature.com/hdy ORIGINAL ARTICLE High heritability for Ascaris and Trichuris infection levels in pigs P Nejsum1,2, A Roepstorff1,CBJrgensen2, M Fredholm2, HHH Go¨ring3, TJC Anderson3 and SM Thamsborg1 1Danish Centre for Experimental Parasitology, Department of Veterinary Pathobiology, Faculty of Life Sciences, University of Copenhagen, Copenhagen, Denmark; 2Genetics and Bioinformatics, Department of Animal and Veterinary Basic Sciences, Faculty of Life Sciences, University of Copenhagen, Copenhagen, Denmark and 3Department of Genetics, Southwest Foundation for Biomedical Research, San Antonio, TX, USA Aggregated distributions of macroparasites within their host 0.32–0.73 of the phenotypic variation for T. suis could be populations are characteristic of most natural and experi- attributed to genetic factors. For A. suum, heritabilities of mental infections. We designed this study to measure the 0.29–0.31 were estimated for log (FEC þ 1) at weeks 7–14 amount of variation that is attributable to host genetic factors p.i., whereas the heritability of log worm counts was 0.45. in a pig–helminth system. In total, 195 piglets were produced Strong positive genetic correlations (0.75–0.89) between after artificial insemination of 19 sows (Danish Landrace– T. suis and A. suum FECs suggest that resistance to both Yorkshire crossbreds) with semen selected from 13 indivi- infections involves regulation by overlapping genes. Our data dual Duroc boars (1 or 2 sows per boar; mean litter size: demonstrate that there is a strong genetic component in 10.3; 5–14 piglets per litter).
    [Show full text]
  • An Overview of Anthelmintic Drugs in Ascaris Suum Intestine
    Iowa State University Capstones, Theses and Creative Components Dissertations Spring 2019 An Overview of Anthelmintic Drugs in Ascaris suum Intestine Katie Tharaldson Follow this and additional works at: https://lib.dr.iastate.edu/creativecomponents Part of the Chemicals and Drugs Commons Recommended Citation Tharaldson, Katie, "An Overview of Anthelmintic Drugs in Ascaris suum Intestine" (2019). Creative Components. 262. https://lib.dr.iastate.edu/creativecomponents/262 This Creative Component is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Creative Components by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. Tharaldson Overview of anthelmintic drugs and their receptors Part 1 Abstract In part 1 of this paper, I will discuss Ascaris suum and Ascaris lumbricoides. Ascaris suum acts as a model organism for Ascaris lumbricoides, a parasitic nematode that impacts roughly 1.2 billion people worldwide (de Silva et al. 2003). I will then go into the anthelmintic drugs currently being used to treat these infection, as well as the receptors they act on. In part 2 of this paper, I will discuss the research I did with levamisole, an anthelmintic drug, on nicotinic acetylcholine receptors (nAChRs) in the intestine of Ascaris suum. There were 5 control worms, as well as 5 levamisole treated worms. In the past, the nAChRs have been studied predominantly on the muscle in all nematode species. However, in previous work in the lab, although unpublished, there was promising expression of nAChRs in Ascaris suum intestine.
    [Show full text]
  • Parasites 1: Trematodes and Cestodes
    Learning Objectives • Be familiar with general prevalence of nematodes and life stages • Know most important soil-borne transmitted nematodes • Know basic attributes of intestinal nematodes and be able to distinguish these nematodes from each other and also from other Lecture 4: Emerging Parasitic types of nematodes • Understand life cycles of nematodes, noting similarities and significant differences Helminths part 2: Intestinal • Know infective stages, various hosts involved in a particular cycle • Be familiar with diagnostic criteria, epidemiology, pathogenicity, Nematodes &treatment • Identify locations in world where certain parasites exist Presented by Matt Tucker, M.S, MSPH • Note common drugs that are used to treat parasites • Describe factors of intestinal nematodes that can make them emerging [email protected] infectious diseases HSC4933 Emerging Infectious Diseases HSC4933. Emerging Infectious Diseases 2 Readings-Nematodes Monsters Inside Me • Ch. 11 (pp. 288-289, 289-90, 295 • Just for fun: • Baylisascariasis (Baylisascaris procyonis, raccoon zoonosis): Background: http://animal.discovery.com/invertebrates/monsters-inside-me/baylisascaris- [box 11.1], 298-99, 299-301, 304 raccoon-roundworm/ Video: http://animal.discovery.com/videos/monsters-inside-me-the-baylisascaris- [box 11.2]) parasite.html Strongyloidiasis (Strongyloides stercoralis, the threadworm): Background: http://animal.discovery.com/invertebrates/monsters-inside-me/strongyloides- • Ch. 14 (p. 365, 367 [table 14.1]) stercoralis-threadworm/ Videos: http://animal.discovery.com/videos/monsters-inside-me-the-threadworm.html http://animal.discovery.com/videos/monsters-inside-me-strongyloides-threadworm.html Angiostrongyliasis (Angiostrongylus cantonensis, the rat lungworm): Background: http://animal.discovery.com/invertebrates/monsters-inside- me/angiostrongyliasis-rat-lungworm/ Video: http://animal.discovery.com/videos/monsters-inside-me-the-rat-lungworm.html HSC4933.
    [Show full text]
  • Diagnostic Notes
    DIAGNOSTIC NOTES Pig parasite diagnosis Robert M. Corwin, DVM, PhD arasites in swine have an impact on performance, with effects and the persistence or life span of the parasite. ranging from impaired growth and wasteful feed consumption Postmortem examination should reveal adult worms in their principal to clinical disease, debilitation, and perhaps even death. It is sites of infection, e.g., ascarids in the small intestine. Lesions associ- particularly important to diagnose subclinical parasitism, which can ated with larval infection, such as nodules of Oesophagostomum in have serious economic consequences and which should be treated the colon may not have larvae present or apparent. Lungworms also with ongoing preventive measures. have rather specific sites at least in young worm populations, viz., the Internal parasitism is caused by nematode roundworms and coccidia bronchioles of the diaphragmatic lobes of the lungs. in the gastrointestinal tract, lungworms in the respiratory tract, and by All of these parasites are directly transmissible from the environment ectoparasites. The most commonly encountered gastrointestinal para- with ingestion of eggs or larvae. Strongyloides may also be passed in sites are the large roundworm Ascaris suum, the threadworm Stron- the colostrum or penetrate skin, and transmission of the lung worm gyloides ransomi, the whipworm Trichuris suis, the nodular worm and the kidney worm may involve earthworms. Oesophagostomum dentatum, and the coccidia, especially lsospora suis and Cryptosporidium parvum in neonates and Eimeria spp at Ascaris suum --”large roundworm” weaning. (Figure 1A) Diagnosis of internal parasites is best accomplished by fecal examina- egg: 45-60 µm, yellowish brown, spherical, mammillated (Figure 1B) tion using a flotation technique and/or by necropsy.
    [Show full text]
  • Ascaris Suum Eggs from Naturally Infected Sows
    Original research Peer reviewed Effect of fenbendazole on shedding and embryonation of Ascaris suum eggs from naturally infected sows Jeremy S. Pittman, DVM, MS, Diplomate ABVP; Gil H. Myers, PhD; Kenneth J. Stalder, PhD; Locke A. Karriker, DVM, MS, Diplomate ACVPM Summary were isolated and incubated (embryonation controls (P < .05), but not from each other. Objectives: To determine reduction of study) to determine embryonation rates. Embryonation rates were lower for treat- Ascaris suum egg shedding and ovicidal Groups were compared for time-to-negative ments than controls at 6 and 8 DPT effects in naturally infected commercial (Kaplan-Meier survival analysis); percent (P < .001). negative (chi-square analysis); environ- female breeding swine treated with fenben- Implications: Fenbendazole at various dos- mental burden (analysis of variance); and dazole. ages is effective againstA suum infections in embryonation rates (analysis of variance). Materials and methods: Five shedding sows. Treatment should begin 14 days prior and three embryonation experiments across Results: Time-to-negative ranges were 9.3- to movement into clean farrowing facilities. three commercial sow farms were conducted. 13.1, 8.9-13.1, and 9.8 days post treatment Under the conditions of this study, fenben- Ascaris suum-infected sows were allocated to (DPT) for treatments 1, 2, and 3, respec- dazole demonstrates ovicidal activity against four treatments: untreated controls; 545.5 mg tively; control ranges were 13.4-28.2 DPT. A suum at 4-8 DPT. Treatment sows were 90%-100% negative, fenbendazole, 1 day (Treatment 1); 545.5 mg Received: July 2, 2014 compared to 0.0%-28.6% of controls.
    [Show full text]
  • Ascaris Lumbricoides/Ascaris Suum Genesig Standard
    Primerdesign TM Ltd Ascaris lumbricoides/Ascaris suum NADH dehydrogenase subunit 5 (nad5) gene genesig® Standard Kit 150 tests For general laboratory and research use only Quantification of Ascaris lumbricoides/Ascaris suum genomes. 1 genesig Standard kit handbook HB10.04.10 Published Date: 09/11/2018 Introduction to Ascaris lumbricoides/Ascaris suum Ascaris suum, also known as large roundworm of pigs, is a parasitic nematode that causes ascariasis in pigs. While roundworms in pigs and humans are today considered as two species, A. suum and A. lumbricoides, with different hosts, cross infection between humans and pigs is possible, so researchers have argued they are the same species, e.g.; Ascaris lumbricoides is the largest nematode (roundworm) parasitizing the human intestine. (Adult females: 20 to 35 cm; adult male: 15 to 30 cm.) The A.suum genome is estimated to be 272.8Mbp long and has a GCcontent of 37.9%. This genome has low repeat content (4.4%) and encodes about 18,500 protein-coding genes. Adult worms live in the lumen of the small intestine. A female may produce approximately 200,000 eggs per day, which are passed with the faeces . Unfertilized eggs may be ingested but are not infective. The female produces as many as 200,000 eggs per day for a year. These fertilized eggs become infectious after two weeks in soil; they can persist in soil for 10 years or more. The eggs have a lipid layer which makes them resistant to the effects of acids and alkalis, as well as other chemicals. Fertile eggs begin developing and become infective after 18 days to several weeks depending on the environmental conditions (e.g.
    [Show full text]
  • Anthelmintic Properties of Traditional African and Caribbean
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Copenhagen University Research Information System Anthelmintic properties of traditional African and Caribbean medicinal plants identification of extracts with potent activity against Ascaris suum in vitro Williams, Andrew R.; Soelberg, Jens; Jäger, Anna Published in: Parasite DOI: 10.1051/parasite/2016024 Publication date: 2016 Document version Publisher's PDF, also known as Version of record Document license: CC BY Citation for published version (APA): Williams, A. R., Soelberg, J., & Jäger, A. (2016). Anthelmintic properties of traditional African and Caribbean medicinal plants: identification of extracts with potent activity against Ascaris suum in vitro. Parasite, 23, [24]. https://doi.org/10.1051/parasite/2016024 Download date: 08. Apr. 2020 Parasite 2016, 23,24 Ó A.R. Williams et al., published by EDP Sciences, 2016 DOI: 10.1051/parasite/2016024 Available online at: www.parasite-journal.org RESEARCH ARTICLE OPEN ACCESS Anthelmintic properties of traditional African and Caribbean medicinal plants: identification of extracts with potent activity against Ascaris suum in vitro Andrew R. Williams1,*, Jens Soelberg2, and Anna K. Jäger2 1 Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, 1870 Copenhagen, Denmark 2 Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark Received 6 April 2016, Accepted 2 June 2016, Published online 14 June 2016 Abstract – Ascariasis affects more than 1 billion people worldwide, mainly in developing countries, causing sub- stantial morbidity. Current treatments for Ascaris infection are based on mass drug administration (MDA) with syn- thetic anthelmintic drugs such as albendazole, however continual re-infection and the threat of drug resistance mean that complementary treatment options would be highly valuable.
    [Show full text]
  • So the Butcher Won't Let You Keep Your Pig Livers…Here's
    So the Butcher won’t let you keep your pig livers…here’s why Your Animals are Infected with Large roundworms (Ascaris) Most hogs have Ascaris infections during their lifetimes. These roundworms are usually found in greatest numbers in pigs up to 2 to 3 months of age with a few in older pigs. Sows usually are not clinically affected, but serve as carriers. Roundworms are long (6 to 12 inches), stout, pinkish worms, sometimes with curved tails. The adults live in the small intestine, grazing on the gut lining and ingesting particulate and liquid materials from digesting food. The adult females deposit round, microscopic eggs. Each female lays thousands per day beginning about two months after the pig becomes infected. Eggs may survive for 10 or more years and are quite resistant to cold and disinfectants. They can be destroyed by high-pressure steam heat and sunlight. Because they are sticky, eggs are easily transported by cockroaches, beetles, flies, birds and workers' boots and clothing. Eggs become infective after being outside the pig for one month. When another pig swallows them, they hatch in the stomach or small intestine. The tiny larva that emerges penetrates the gut wall and is carried to the liver through the bloodstream. In the liver, larvae migrate for one-half to one week and then are swept through the bloodstream to the lungs. From there, the larvae are coughed up, swallowed and returned to the small intestine, where they grow and mature within two months. Thus pigs may be 1-1/2 to 2 months of age before eggs can be detected in fecal samples, but immature adult worms may be passed earlier.
    [Show full text]
  • Sustainable Control of Gastrointestinal Parasite Infections in Ruminants
    Sustainable control of gastrointestinal parasite infections in ruminants Word count: "< 28.533 >" Laurens Zwanenburg Student number: 01509101 Supervisor: Prof. dr. Edwin Claerebout Supervisor: Prof. dr. Stig Thamsborg A dissertation submitted to Ghent University in partial fulfilment of the requirements for the degree of Master of Veterinary Medicine Academic year: 2017 - 2018 Ghent University, its employees and/or students, give no warranty that the information provided in this thesis is accurate or exhaustive, nor that the content of this thesis will not constitute or result in any infringement of third-party rights. Ghent University, its employees and/or students do not accept any liability or responsibility for any use which may be made of the content or information given in the thesis, nor for any reliance which may be placed on any advice or information provided in this thesis. Acknowledgements First of all, many thanks to Prof. dr. E. Claerebout and Prof. dr. S. Thamsborg for their supervision and guidance with the development and implementation of this master thesis. Both supervisors allowed me to work independently within their departments and provided helpful feedback on the results of the study. Furthermore, I would like to thank Prof. dr. Peter Geldhof and O. Paerewijck for their technical support with the resazurin-reduction assay, which was conducted at the University of Ghent. For the larval- migration-inhibition assay, which was conducted at the University of Copenhagen, I would like to thank Prof. dr. A. Williams for his technical support. Finally, I would like to acknowledge both universities and the Erasmus+ Programme for making the international exchange possible.
    [Show full text]
  • Early Developmental Stages of Nematodes Occurring in Swine
    EARLY DEVELOPMENTAL STAGES OF NEMATODES OCCURRING IN SWINE By JOSEPH E. ALICATA Junior Zoolofllst Zoological Division Bureau of Animal Industry UNITED STATES DEPARTMENT OF AGRICULTURE, WASHINGTON, D. C. Technical Bulletin No. 489 December 1935 UNITED STATES DEPARTMENT OF AGRICULTURE WASHINGTON, D. C. EARLY DEVELOPMENTAL STAGES OF NEMATODES OCCURRING IN SWINE By JOSEPH E. ALICATA Junior zoologist, Zoological Division, Bureau of Animal Industry CONTENTS Page Morphological and experimental data—Con. Page Introduction 1 Ascaridae. _ 44 Historical résumé 2 Ascaris suum Goeze, 1782 44 General remarks on life histories of groups Trichuridae 47 studied _. 4 Trichuris suis (Schrank, 1788) A. J. Abbreviations and symbols used in illus- Smith, 1908 47 trations __ 5 Trichostrongylidae 51 Morphological and experimental data 5 HyostrongylîLS rubidus (Hassall and Spiruridae 5 Stiles, 1892) HaU,.1921 51 Gongylonema pulchrum Molin, 1857.. 5 Strongylidae. _— — .-. 68 Oesophagostomum dentatum (Ru- Ascarops strongylina (Rudolphi, 1819) dolphi, 1803) Molin, 1861 68 Alicata and Mclntosh, 1933 21 Stephanurus dentatus Diesing, 1839..- 73 Physocephalus sexalatus (Molin, 1860) Strongyloididae 79 Diesing, 1861 27 Strongyloides ransomi Schwartz and Metastrongyhdae 33 AUcata, 1930. 79 Metastrongylus salmi Gedoelst, 1923— 33 Comparative morphology of eggs and third- Metastrongylus elongattbs (Dujardin, stage larvae of some nematodes occurring 1845) Railliet and Henry, 1911 37 in swine 85 Choerostrongylus pudendotectus (Wos- Summary 87 tokow, 1905) Skrjabin, 1924 41 Literature cited 89 INTRODUCTION The object of this bulletin is to present the result^ of an investiga- tion on the early developmental stages of nematodes of common occur- rence in domestic swine. Observations on the stages in the definitive host of two of the nematodes, Gongylonema pulchrum and Hyostrongy- lus rubidus, are only briefly given, however, since little is known of these stages in these nematodes.
    [Show full text]
  • Are Ascaris Lumbricoides and Ascaris Suum a Single Species? Daniela Leles1, Scott L Gardner2, Karl Reinhard3, Alena Iñiguez4 and Adauto Araujo5*
    Leles et al. Parasites & Vectors 2012, 5:42 http://www.parasitesandvectors.com/content/5/1/42 REVIEW Open Access Are Ascaris lumbricoides and Ascaris suum a single species? Daniela Leles1, Scott L Gardner2, Karl Reinhard3, Alena Iñiguez4 and Adauto Araujo5* Abstract Since the original description and naming of Ascaris lumbricoides from humans by Linnaeus in 1758 and later of Ascaris suum from pigs by Goeze 1782, these species have been considered to be valid. Four hypotheses relative to the conspecificity or lack thereof (and thus origin of these species) are possible: 1) Ascaris lumbricoides (usually infecting humans) and Ascaris suum (recorded mostly from pigs) are both valid species, with the two species originating via a speciation event from a common ancestor sometime before the domestication of pigs by humans, or 2) Ascaris lumbricoides in humans is derived directly from the species A. suum found in pigs with A. suum then existing as a persistent ancestor after formation of A. lumbricoides,or3)Ascaris suum is derived directly from A. lumbricoides with the persistent ancestor being A. lumbricoides and A. suum being the newly derived species, and finally, 4) Ascaris lumbricoides and A. suum are the same species, this hypothesis being supported by studies showing both low morphological and low genetic divergence at several genes. We present and discuss paleoparasitological and genetic evidence that complement new data to evaluate the origin and evolution of Ascaris spp. in humans and pigs, and the uniqueness of the species in both hosts. Finally, we conclude that Ascaris lumbricoides and A. suum are a single species and that the name A.
    [Show full text]