DOCSLIB.ORG

Speciation in the Genus Cloacina (Nematoda: Strongylida): Species flocks and Intra-Host Speciation

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Speciation in the Genus Cloacina (Nematoda: Strongylida): Species flocks and Intra-Host Speciation 1828 Speciation in the genus Cloacina (Nematoda: Strongylida): species flocks and intra-host speciation N. B. CHILTON1, M. A. SHUTTLEWORTH2, F. HUBY-CHILTON2,A.V.KOEHLER2, A. JABBAR2,R.B.GASSER2 and I. BEVERIDGE2* 1 Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada 2 Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia (Received 1 April 2017; revised 13 June 2017; accepted 13 June 2017; first published online 12 July 2017) SUMMARY Sequences of the first and second internal transcribed spacers (ITS1 + ITS2) of nuclear ribosomal DNA were employed to determine whether the congeneric assemblages of species of the strongyloid nematode genus Cloacina, found in the forest- omachs of individual species of kangaroos and wallabies (Marsupialia: Macropodidae), considered to represent species flocks, were monophyletic. Nematode assemblages examined in the black-striped wallaby, Macropus (Notamacropus) dor- salis, the wallaroos, Macropus (Osphranter) antilopinus/robustus, rock wallabies, Petrogale spp., the quokka, Setonix bra- chyurus, and the swamp wallaby, Wallabia bicolor, were not monophyletic and appeared to have arisen by host colonization. However, a number of instances of within-host speciation were detected, suggesting that a variety of methods of speciation have contributed to the evolution of the complex assemblages of species present in this genus. Key words: Cloacina, Nematoda, Strongylida, speciation, species flocks, internal transcribed spacers. INTRODUCTION differences in the distribution of species within the gastro-intestinal tract (Ogbourne, 1976;Mfitilodze The phenomenon of ‘species flocks’, that is the and Hutchinson, 1985; Bucknell et al. 1995; occurrence of numerous species of congeneric (or Stancampiano et al. 2010). Comparably detailed confamilial) parasites in the same host species, has studies on the strongyloid nematodes of elephants been the focus of a number of studies, particularly and rhinoceroces have not been conducted, but of parasitic nematodes. One of the best-known four genera and 49 species belonging to the related examples of the phenomenon is that of the oxyuroid strongyloid tribes Kiluluminea, Murshidinea and nematodes found in the colon of tortoises (Schad, Quiloninea are known to occur in their large intes- 1963; Petter, 1966). In this instance, each species tines (Chabaud, 1957; Round, 1968; Canaris and of tortoise harbours large numbers of congeneric or Gardner, 2003; Beveridge and Jabbar, 2013). In confamilial nematode species, all belonging to the the case of kangaroos and wallabies (family family Pharyngodonidae (Petter, 1966). However, Macropodidae) some 36 genera and 256 species of there are differences in the longitudinal and radial nematodes belonging to the sub-family Cloacininae distributions of these nematode species within the occur in the sacculated forestomach (Beveridge and colon of the host (Schad, 1963). Other examples of Chilton, 2001), frequently in large numbers species flocks of parasitic nematodes are those (Beveridge and Arundel, 1979), with again, some found in the large intestines of equids, elephants degree of spatial separation within the stomach and rhinoceroses, as well as those in the sacculated (Mykytowycz, 1964; Arundel et al. 1979; Pamment forestomachs of kangaroos and wallabies (Inglis, et al. 1994). 1971). All of these nematodes have direct life- In a critical review of the phenomenon of species cycles with the ingestion of eggs or third-stage flocks in parasitic helminths, Kennedy and Bush larvae from the environment (Anderson, 2000). (1992) indicated several difficulties in the application In the case of equids (horses, donkeys and zebras), of this appellation to the examples cited above. First 14 genera and 50 species of strongyloid nematodes of all, these authors noted that species flocks, accord- belonging to the tribe Cyathostominea are currently ing to classical definitions, could be defined either by recognized (Lichtenfels et al. 2008), with the ecological parameters such as co-occurrence (Mayr, common co-occurrence of many species (Bucknell 1984) and endemism (Ribbink, 1984) or could be et al. 1996; Anjos and Rodrigues, 2003;Buet al. circumscribed phylogenetically, with a species flock 2009; Kuzmina et al. 2009), but again with being a monophyletic assemblage (Greenwood, 1984). In the former case, such associations of mul- * Corresponding author: Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, tiple congeners could develop through a number of Parkville, Victoria, Australia. E-mail: ibeve@unimelb. host colonization events, while in the latter case, edu.au the communities could evolve through intra-host Parasitology (2017), 144, 1828–1840. © Cambridge University Press 2017 doi:10.1017/S0031182017001238 Downloaded from https://www.cambridge.org/core. University of Athens, on 30 Sep 2021 at 12:41:00, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0031182017001238 Nematode species flocks in kangaroos 1829 speciation. Intra-host speciation (Price, 1980; of host specificity (Beveridge et al. 2002). In add- Poulin, 2007) or even sympatric speciation (Kunz, ition, the study of a single genus (although the 2002) are considered to be potentially common monophyly of Cloacina has not yet been investigated modes of evolution in parasites. using molecular methods) overcomes the difficulty The phylogenetic definition of species flocks has of deciding whether species flocks should be consid- been successfully applied to cichlid fishes ered as being composed of congeners or whether the (Seehausen, 2006)andtorockfishes (Alesandrini concept should expand to con-sub- familiar or con- and Bernardi, 1999), but the paucity of rigorous familiar taxa (see Kennedy and Bush, 1992), a poten- phylogenetic studies of parasitic nematodes means tial complication in the studies of the nematode that this definition is often not applicable. In the assemblages of equids. Furthermore, studies to case of the cyathostomin nematodes of equids (Equus date of different species of kangaroos and wallabies spp.), available molecular evidence suggests that they (seven species of the currently recognized 54 host do indeed form a monophyletic assemblage (Hung species were studied by Beveridge et al. 2002) have et al. 2000;McDonnellet al. 2000). The same situ- shown that assemblages of nematode species range ation may apply to the strongyloid nematodes of ele- across a continuum, from three to 12. This spectrum phants as most species belong to two related tribes, of hosts with varying numbers of co-occurring con- the Murshidiinea and Quiloninea (Lichtenfels, geners is not represented in any other host-parasite 1980). This may well also apply to the Cloacininae system as there remain only five extant species of in macropodids. However, appropriate morphological equids (all with a very similar parasite fauna), three and molecular phylogenetic studies are lacking. A species of elephants and four species of rhinoceros, similar situation pertains, in the case of molecular all relicts of formerly more diverse faunas studies, to the oxyuroid nematodes in tortoises for (Franzen, 2010). In addition a number of the latter which molecular data are lacking. As a consequence, host species are endangered thereby imposing a limi- among nematodes, it appears that the phylogenetic tation on parasitological studies. definition of a species flock may only be applicable In an attempt to address the question of whether currently to the cyathostomin nematodes of equids. the species flocks of Cloacina seen in macropodids A molecular study of species of Onchocerca occurring are monophyletic, Beveridge et al. (2002) undertook in cattle also suggests within-host speciation in this a phylogenetic analysis based on morphological nematode genus, but the result is dependent upon characters. However, given that only a limited the inclusion of remaining congeners (Morales-Hojas number of morphological characters was available, et al. 2006). a common phenomenon for parasitic nematodes, In considering the ecological definition of a the resulting phylogeny exhibited a relatively low species flock, Kennedy and Bush (1992) pointed consistency index. In spite of this reservation, it out that the criterion of ‘co-occurrence’ was also was suggested that while several nematode species difficult to apply since, for several parasite groups, pairs could be identified in individual host species, relevant data were not available on the co-occurrence there was no strong evidence for the existence of of congeneric or confamilial parasites within an indi- monophyletic species flocks (Beveridge et al. 2002). vidual host; rather published data described the It was therefore tentatively suggested that the assem- meta-community. This ecological difference is also blages might have arisen through host switching. reflected in phylogenetic studies in which the criter- Given the difficulties encountered in the use of ion of sympatry in potential examples of intra-host morphological characters to establish phylogenetic speciation can be problematical (McCoy, 2003). relationships among nematodes, it was decided to Data on the co-occurrence of species of nematodes re-examine the problem using molecular methods. are however available for the cyathostomins of The combined first and second internal transcribed equids (Bucknell et al. 1996; Anjos and Rodrigues, spacers (ITS-1 and ITS-2) of nuclear ribosomal
Load more

Recommended publications
  • Fibre Couplings in the Placenta of Sperm Whales, Grows to A
    news and views Most (but not all) nematodes are small Daedalus and nondescript. For example, Placento- T STUDIOS nema gigantissima, which lives as a parasite Fibre couplings in the placenta of sperm whales, grows to a CS./HOL length of 8 m, with a diameter of 2.5 cm. The The nail, says Daedalus, is a brilliant and free-living, marine Draconema has elongate versatile fastener, but with a fundamental O ASSO T adhesive organs on the head and along the contradiction. While being hammered in, HO tail, and moves like a caterpillar. But the gen- it is a strut, loaded in compression. It must BIOP eral uniformity of most nematode species be thick enough to resist buckling. Yet has hampered the establishment of a classifi- once in place it is a tie, loaded in tension, 8 cation that includes both free-living and par- and should be thin and flexible to bear its asitic species. Two classes have been recog- load efficiently. He is now resolving this nized (the Secernentea and Adenophorea), contradiction. based on the presence or absence of a caudal An ideal nail, he says, should be driven sense organ, respectively. But Blaxter et al.1 Figure 2 The bad — eelworm (root knot in by a force applied, not to its head, but to have concluded from the DNA sequences nematode), which forms characteristic nodules its point. Its shaft would then be drawn in that the Secernentea is a natural group within on the roots of sugar beet and rice. under tension; it could not buckle, and the Adenophorea.
    [Show full text]
  • Epidemiology of Angiostrongylus Cantonensis and Eosinophilic Meningitis
    Epidemiology of Angiostrongylus cantonensis and eosinophilic meningitis in the People’s Republic of China INAUGURALDISSERTATION zur Erlangung der Würde eines Doktors der Philosophie vorgelegt der Philosophisch-Naturwissenschaftlichen Fakultät der Universität Basel von Shan Lv aus Xinyang, der Volksrepublik China Basel, 2011 Genehmigt von der Philosophisch-Naturwissenschaftlichen Fakult¨at auf Antrag von Prof. Dr. Jürg Utzinger, Prof. Dr. Peter Deplazes, Prof. Dr. Xiao-Nong Zhou, und Dr. Peter Steinmann Basel, den 21. Juni 2011 Prof. Dr. Martin Spiess Dekan der Philosophisch- Naturwissenschaftlichen Fakultät To my family Table of contents Table of contents Acknowledgements 1 Summary 5 Zusammenfassung 9 Figure index 13 Table index 15 1. Introduction 17 1.1. Life cycle of Angiostrongylus cantonensis 17 1.2. Angiostrongyliasis and eosinophilic meningitis 19 1.2.1. Clinical manifestation 19 1.2.2. Diagnosis 20 1.2.3. Treatment and clinical management 22 1.3. Global distribution and epidemiology 22 1.3.1. The origin 22 1.3.2. Global spread with emphasis on human activities 23 1.3.3. The epidemiology of angiostrongyliasis 26 1.4. Epidemiology of angiostrongyliasis in P.R. China 28 1.4.1. Emerging angiostrongyliasis with particular consideration to outbreaks and exotic snail species 28 1.4.2. Known endemic areas and host species 29 1.4.3. Risk factors associated with culture and socioeconomics 33 1.4.4. Research and control priorities 35 1.5. References 37 2. Goal and objectives 47 2.1. Goal 47 2.2. Objectives 47 I Table of contents 3. Human angiostrongyliasis outbreak in Dali, China 49 3.1. Abstract 50 3.2.
    [Show full text]
  • Managing Hookworms in the Landscape 1
    Archival copy: for current recommendations see http://edis.ifas.ufl.edu or your local extension office. ENY-017 Managing Hookworms in the Landscape 1 Robert A. Dunn and Ellis C. Greiner2 "Hookworms" properly refers to many genera of • A. tubaeforme is the common hookworm of nematodes in the Family Ancylostomatidae of the cats, distributed world-wide; similar to A. Order Strongylida, but this discussion addresses caninum, but generally smaller. primarily those in the genus Ancylostoma, which many animal health professionals consider to be the • Uncinaria stenocephala occurs in the small most important genus of hookworms. This genus intestine of dogs, cats, foxes, wolves, and related includes the most common hookworms of domestic carnivores. It is occasionally recovered from dogs and cats in tropical and warm temperate stray dogs in Florida, but may not occur climates, the hookworms with which most people in endemically here -- the infections that are Florida come into contact. The "northern carnivore detected may have occurred farther north, before hookworm," Uncinaria stenocephala, also occurs in the host animals came to Florida. Florida but much less frequently than Ancylostoma Importance as Animal and Human spp. Parasites Four species are significant in Florida; the three Ancylostoma spp. represent 90 - 95% of hookworms Widely distributed wherever dogs and cats are identified here: kept as pets, hookworms are found commonly in the small intestines of hosts in which they can complete • Ancylostoma caninum, the dog hookworm, is their life cycles. Hookworms suck blood from the found in the small intestine of dogs, foxes, intestinal wall. The degree of blood sucking varies coyotes, wolves, bears, and other wild carnivores among these hookworms.
    [Show full text]
  • The Biology of Strongyloides Spp.* Mark E
    The biology of Strongyloides spp.* Mark E. Viney1§ and James B. Lok2 1School of Biological Sciences, University of Bristol, Bristol, BS8 1TQ, UK 2Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104-6008, USA Table of Contents 1. Strongyloides is a genus of parasitic nematodes ............................................................................. 1 2. Strongyloides infection of humans ............................................................................................... 2 3. Strongyloides in the wild ...........................................................................................................2 4. Phylogeny, morphology and taxonomy ........................................................................................ 4 5. The life-cycle ..........................................................................................................................6 6. Sex determination and genetics of the life-cycle ............................................................................. 8 7. Controlling the life-cycle ........................................................................................................... 9 8. Maintaining the life-cycle ........................................................................................................ 10 9. The parasitic phase of the life-cycle ........................................................................................... 10 10. Life-cycle plasticity .............................................................................................................
    [Show full text]
  • The White-Nosed Coati (Nasua Narica) Is a Naturally Susceptible Definitive
    Veterinary Parasitology 228 (2016) 93–95 Contents lists available at ScienceDirect Veterinary Parasitology jou rnal homepage: www.elsevier.com/locate/vetpar Short communication The white-nosed coati (Nasua narica) is a naturally susceptible definitive host for the zoonotic nematode Angiostrongylus costaricensis in Costa Rica a,∗ b c a Mario Santoro , Alejandro Alfaro-Alarcón , Vincenzo Veneziano , Anna Cerrone , d d b b Maria Stefania Latrofa , Domenico Otranto , Isabel Hagnauer , Mauricio Jiménez , a Giorgio Galiero a Istituto Zooprofilattico Sperimentale del Mezzogiorno, Portici, Naples, Italy b Escuela de Medicina Veterinaria, Universidad Nacional, Heredia, Costa Rica c Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy d Dipartimento di Medicina Veterinaria, Università degli Studi di Bari, Valenzano, Bari, Italy a r t i c l e i n f o a b s t r a c t Article history: Angiostrongylus costaricensis (Strongylida, Angiostrongylidae) is a roundworm of rodents, which may Received 17 June 2016 cause a severe or fatal zoonosis in several countries of the Americas. A single report indicated that the Received in revised form 23 August 2016 white-nosed coati (Nasua narica), acts as a potential free-ranging wildlife reservoir. Here we investigated Accepted 24 August 2016 the prevalence and features of A. costaricensis infection in two procyonid species, the white-nosed coati and the raccoon (Procyon lotor) from Costa Rica to better understand their possible role in the epidemi- Keywords: ology of this zoonotic infection. Eighteen of 32 (56.2%) white-nosed coatis collected between July 2010 Abdominal angiostrongyliasis and March 2016 were infected with A.
    [Show full text]
  • Flatworms Have Lost the Right Open Reading Frame Kinase 3 Gene During Evolution
    OPEN Flatworms have lost the right open SUBJECT AREAS: reading frame kinase 3 gene during PARASITE BIOLOGY GENETICS evolution Bert Breugelmans1, Brendan R. E. Ansell1, Neil D. Young1, Parisa Amani4, Andreas J. Stroehlein1, Received Paul W. Sternberg2, Aaron R. Jex1, Peter R. Boag3, Andreas Hofmann1,4 & Robin B. Gasser1 28 November 2014 Accepted 1Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia, 2HHMI, Division of 26 February 2015 Biology, California Institute of Technology, Pasadena, California, USA, 3Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia, 4Structural Chemistry Program, Eskitis Institute, Griffith University, Brisbane, Australia. Published 15 May 2015 All multicellular organisms studied to date have three right open reading frame kinase genes (designated riok-1, riok-2 and riok-3). Current evidence indicates that riok-1 and riok-2 have essential roles in ribosome Correspondence and biosynthesis, and that the riok-3 gene assists this process. In the present study, we conducted a detailed bioinformatic analysis of the riok gene family in 25 parasitic flatworms (platyhelminths) for which extensive requests for materials genomic and transcriptomic data sets are available. We found that none of the flatworms studied have a riok- should be addressed to 3 gene, which is unprecedented for multicellular organisms. We propose that, unlike in other eukaryotes, the R.B.G. (robinbg@ loss of RIOK-3 from flatworms does not result in an evolutionary disadvantage due to the unique biology unimelb.edu.au) and physiology of this phylum. We show that the loss of RIOK-3 coincides with a loss of particular proteins associated with essential cellular pathways linked to cell growth and apoptosis.
    [Show full text]
  • Biology: Taxonomy, Identification, and Life Cycle of Angiostrongylus Cantonensis
    Biology: taxonomy, identification, and life cycle of Angiostrongylus cantonensis Robert H. Cowie Pacific Biosciences Research Center, University of Hawaii, Honolulu, Hawaii photo: Juliano Romanzini, courtesy of Carlos Graeff Teixeira RAT LUNG WORM DISEASE SCIENTIFIC WORKSHOP HONOLULU, HAWAII AUGUST 16 - 18, 2011 CLASSIFICATION AND DIVERSITY PHYLUM: Nematoda CLASS: Rhabditea ORDER: Strongylida SUPERFAMILY: Metastrongyloidea FAMILY: Angiostrongylidae • Around 19 species are recognized worldwide in the genus Angiostrongylus • Two species infect humans widely: - Angiostrongylus costaricensis Morera & Céspedes, 1971 causes abdominal angiostrongyliasis, especially a problem in South America - Angiostrongylus cantonensis (Chen, 1935) causes eosinophilic meningitis RAT LUNG WORM DISEASE SCIENTIFIC WORKSHOP HONOLULU, HAWAII AUGUST 16 - 18, 2011 NOMENCLATURE Angiostrongylus cantonensis (Chen, 1935) • First described by Chen (1935) as Pulmonema cantonensis • Also described as Haemostrongylus ratti by Yokogawa (1937) • Pulmonema subsequently synonymized with Angiostrongylus and ratti with cantonensis • Angiostrongylus cantonensis then widely accepted as the name of this species • Ubelaker (1986) split Angiostrongylus into five genera: Angiostrongylus (in carnivores), Parastrongylus (murids), Angiocaulus (mustelids), Gallegostrongylus (gerbils and one murid), Stefanskostrongylus (insectivores) • And placed cantonensis in the genus Parastrongylus • But this classification is not widely used and most people still refer to the species as Angiostrongylus
    [Show full text]
  • Identification of Protective Immune Responses and the Immunomodulatory Capacity of Litomosoides Sigmodontis
    Identification of protective immune responses and the immunomodulatory capacity of Litomosoides sigmodontis Dissertation zur Erlangung des Doktorgrades (Dr. rer. nat.) der Mathematisch-Naturwissenschaftlichen Fakultät der Rheinischen Friedrich-Wilhelms-Universität Bonn vorgelegt von JESUTHAS AJENDRA aus Dillingen/Saar Bonn 2016 i Angefertigt mit Genehmigung der Mathematisch-Naturwissenschaftlichen Fakultät der Rheinischen Friedrich-Wilhelms-Universität Bonn 1. Gutachter: Prof. Dr. Achim Hörauf 2. Gutachter: Prof. Dr. Waldemar Kolanus Tag der Promotion: 25.08.2016 ii Erscheinungsjahr: 2016 Erklärung Die hier vorgelegte Dissertation habe ich eigenständig und ohne unerlaubte Hilfsmittel angefertigt. Die Dissertation wurde in der vorgelegten oder in ähnlicher Form noch bei keiner anderen Institution eingereicht. Es wurden keine vorherigen oder erfolglosen Promotionsversuche unternommen. Bonn, 23.03.2016 Teile dieser Arbeit wurden vorab veröffentlicht in folgenden Publikationen: “ST2 deficiency does not impair type 2 immune responses during chronic filarial infection but leads to an increased microfilaremia due to an impaired splenic microfilarial clearance.” Ajendra J, Specht S, Neumann AL, Gondorf F, Schmidt D, Gentil K, Hoffmann WH, Taylor MJ, Hoerauf A, Hübner MP. PLoS One. 2014 Mar 24;9(3):e93072. doi: 10.1371/journal.pone.0093072. eCollection 2014. “Development of patent Litomosoides sigmodontis infections in semi-susceptible C57BL/6 mice in the absence of adaptive immune responses.” Layland LE, Ajendra J, Ritter M, Wiszniewsky A, Hoerauf A, Hübner MP. Parasit Vectors. 2015 Jul 25;8:396. doi: 10.1186/s13071-015-1011-2. “Combination of worm antigen and proinsulin prevents type 1 diabetes in NOD mice after the onset of insulitis.” Ajendra J, Berbudi A, Hoerauf A, Hübner MP. Clin Immunol. 2016 Feb 16; 164:119- 122.
    [Show full text]
  • Overview of the Order Strongylida
    Overview of the Order Strongylida Objectives: 1) Describe the general structure and function of the copulatory bursa of adult males of the Order Strongylida (“the bursate worms”). 2) Compare buccal area morphology of (a) Trichostrongyloidea, (b) Strongyloidea, (c) Ancylostomatoidea, and (d) Metastrongyloidea. 3) Describe the life cycle stages outside of the host for the four superfamilies listed below: (a) Trichostrongyloidea (includes the following eight genera: Trichostrongylus, Ostertagia, Haemonchus, Cooperia, Nematodirus [variation in life cycle], Dictyocaulus, Hyostrongylus, Ollulanus [variation in life cycle]); (b) Strongyloidea (includes the following five genera: Strongylus, Triodontophorus, cyathostomes [many different small strongyles], Oesophagostomum, Stephanurus [variation in life cycle]). (c) Ancylostomatoidea (includes the following three genera: Ancylostoma, Uncinaria, Bunostomum); (d) Metastrongyloidea (includes the following seven genera: Metastrongylus, Protostrongylus, Muellerius, Parelaphostrongylus, Crenosoma, Aelurostrongylus and Filaroides [variation in life cycle]). 4) Describe the pathogenesis and etiology of disease associated with Ostertagia in cattle, Haemonchus in sheep. 5) Outline the general control measures for trichostrongyles (Trichostrongylus, Ostertagia, Haemonchus and Cooperia) in cattle. 6) Outline the general control measures for trichostrongyles in sheep. 7) Describe the pathogenesis and etiology of pneumonia caused by Dictyocaulus. Outline: I. General morphology of the Order Strongylidea (bursate worms): distinctive copulatory bursa on adult males. A. Structure 1. Well-developed dorsal, ventral and lateral expansions of the surface cuticle at the posterior end, referred to as lobes. 2. Lobes supported by muscular rays. 3. Exception in the superfamily Metastrongyloidea where copulatory bursa is less well- developed. B. Function 1. To grasp the female worm at the vulvar site. 2. To facilitate male spicule insertion and movement of sperm from the male cloaca to the female vulva.
    [Show full text]
  • Helminths (Parasitic Worms)
    Helminths (Parasitic worms) Kingdom Animalia Phylum Platyhelminths Phylum Nematoda Trichurida Ascaridida Rhabditita Strongylida Spirurida Trichuris Trichinella Trichuris trichuria AKA: Whipworm - posterior end Definitive Host: Humans, pigs and monkeys Intermediate Host: None Geographic distribution: Approx 800 million infections/year Cosmopolitan, including southern U.S. Warm Climate High rainfall Unsanitary conditions Use of nightsoil as fertilizer Geophagy Trichuris trichuria Location: large intestine from cecum and appendix to rectum Burrows head into mucosa Transmission: Ingestion of embryonated eggs, usually in contaminated food Requires high humidity, warm climate and shade to develop properly. Early stage of development 1 Trichuris trichuria Life Cycle Eggs embryonate in soil (~ 21 days) Rectal prolapse Trichuris trichuria Pathology and Symptoms: Low-level infections (<100 worms) are asymptomatic Large infections can result in diarrhea, bloody stool, abdominal pain and rectal prolapse Prolonged infection in children may cause developmental retardation Often associated with Ascaris lumbricoides infections. Mode of transmission same Treatment: Mebendazole or albendazole. Rectal prolapse - surgery Trichuris trichuria Diagnosis: bipolar eggs in feces. Colonoscopy can also uncover worm infections Females may lay 3,000 to 20,000 eggs a day for many years. There are 60-70 species in this genus, all live in large intestine T. felis – cats T. discolor – cattle T. leporis – rabbits T. muris – rodents T. ovis – sheep T. vulpis – canids Occasionally infects humans T. suis – pigs 2 The Hygiene Hypothesis There has been a considerable increase in the diagnosis of autoimmune diseases and allergies over the second half of the 20th century Prevalence of allergies in urban areas appears higher than in rural environments Environmental factors like pollution, nutrition etc.
    [Show full text]
  • Zoonotic Helminths Affecting the Human Eye Domenico Otranto1* and Mark L Eberhard2
    Otranto and Eberhard Parasites & Vectors 2011, 4:41 http://www.parasitesandvectors.com/content/4/1/41 REVIEW Open Access Zoonotic helminths affecting the human eye Domenico Otranto1* and Mark L Eberhard2 Abstract Nowaday, zoonoses are an important cause of human parasitic diseases worldwide and a major threat to the socio-economic development, mainly in developing countries. Importantly, zoonotic helminths that affect human eyes (HIE) may cause blindness with severe socio-economic consequences to human communities. These infections include nematodes, cestodes and trematodes, which may be transmitted by vectors (dirofilariasis, onchocerciasis, thelaziasis), food consumption (sparganosis, trichinellosis) and those acquired indirectly from the environment (ascariasis, echinococcosis, fascioliasis). Adult and/or larval stages of HIE may localize into human ocular tissues externally (i.e., lachrymal glands, eyelids, conjunctival sacs) or into the ocular globe (i.e., intravitreous retina, anterior and or posterior chamber) causing symptoms due to the parasitic localization in the eyes or to the immune reaction they elicit in the host. Unfortunately, data on HIE are scant and mostly limited to case reports from different countries. The biology and epidemiology of the most frequently reported HIE are discussed as well as clinical description of the diseases, diagnostic considerations and video clips on their presentation and surgical treatment. Homines amplius oculis, quam auribus credunt Seneca Ep 6,5 Men believe their eyes more than their ears Background and developing countries. For example, eye disease Blindness and ocular diseases represent one of the most caused by river blindness (Onchocerca volvulus), affects traumatic events for human patients as they have the more than 17.7 million people inducing visual impair- potential to severely impair both their quality of life and ment and blindness elicited by microfilariae that migrate their psychological equilibrium.
    [Show full text]
  • Rat Lungworm Angiostrongylus Cantonensis (Chen, 1935) (Nematoda: Strongylida: Metastrongylida)1 John Capinera and Heather S
    EENY570 Rat Lungworm Angiostrongylus cantonensis (Chen, 1935) (Nematoda: Strongylida: Metastrongylida)1 John Capinera and Heather S. Walden2 The Featured Creatures collection provides in-depth profiles tamarin in Alabama (Kottwitz et al. 2004). Various species of insects, nematodes, arachnids and other organisms of rats are the definitive hosts, and the only hosts in which relevant to Florida. These profiles are intended for the use of the adult stage of the nematode occurs. However, third- interested laypersons with some knowledge of biology as well stage larvae are infective to humans if they are accidentally as academic audiences. consumed. Ingested worms migrate to the central nervous system of humans and cause eosinophilic meningitis, Introduction and Distribution which often is manifested by fever, headache, stiff neck, nausea, vomiting, fatigue, body ache, skin irritations, and Like many pest and disease problems, rat lungworm photophobia (Slom et al. 2002). The signs and symptoms (Angiostrongylus cantonensis) has been slowly spreading may persist for weeks or months. around the world. First described by Chen (1935) from rats in China, the medical significance of this parasite was overlooked until 1944 when it was found infecting humans in Taiwan. Even then, because the report was published in Japanese, its importance remained largely unknown. In 1955, Mackerras and Sandars found this nematode among rats in Brisbane, Australia, and described its life cycle, including the importance of its molluscan intermediate hosts. It was found in Hawaii in 1960, and Tahiti in 1961. It has since been detected in many regions of the world, including Cuba (1981), Puerto Rico (1986), New Orleans (1988), and Florida (2003).
    [Show full text]