DOCSLIB.ORG

Occurrence of the Myxosporean Emaciation Disease Caused by Enteromyxum Leei in Cultured Japanese Flounder Paralichthys Olivaceus

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Occurrence of the Myxosporean Emaciation Disease Caused by Enteromyxum Leei in Cultured Japanese Flounder Paralichthys Olivaceus ‹›•aŒ¤‹† Fish Pathology,40(4),175-180,2005.12 2005 The Japanese Society of Fish Pathology Occurrence of the Myxosporean Emaciation Disease Caused by Enteromyxum leei in Cultured Japanese Flounder Paralichthys olivaceus Hiroshi Yasuda1 ,Tsuyoshi Ooyama1, Atsushi Nakamura1, Kazuo Iwata1, Oswaldo Palenzuela2 and Hiroshi Yokoyama3* 1 Miyazaki Prefectural Fisheries Experimental Station,Miyazaki,889-2162,Japan 2Instituto de Acuicultura de Torre de la Sal(CSIC) ,12595 Ribera de Cabanes, Castellon, Spain 3 Department of Aquatic Bioscience , Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657,Japan (Received July 29,2005) ABSTRACT-The myxosporean emaciation disease has been recently found in Japanese flounder Paralichthys olivaceus cultured in land-based tanks in Miyazaki Prefecture, Japan. Affected fish showed external signs of distended abdomen, rectal prolapse, sunken eyes and a typical bony ridge on the skull. Parasitological and histopathological examinations revealed that the develop mental stages of Enteromyxum Ieei parasitized the intestinal epithelium of diseased fish. No other enteric myxozoans were observed in the affected fish. A molecular analysis of SSU rDNA con firmed that the causative myxozoan was identified as E. leei. Experimental transmission of E. leei was achieved to naive Japanese flounder and tiger puffer Takifugu rubripes by feeding with gut tissues taken from infected Japanese flounder. The present study indicates that the myxosporean emaciation disease of Japanese flounder is caused by E. leei. Key words: Enteromyxum leei, Myxozoa, emaciation disease , Paralichthys olivaceus, Japanese flounder, Takifugu rubripes, tiger puffer Since the mid-1990s, the myxosporean emaciation farm was situated in the vicinity of a tiger puffer farm, has occurred extensively in many farmsdisease of tiger where the myxosporean emaciation disease was puffer Takifugu rubripes in sites located in western enzootic. The first outbreak of this disease was in Japan. Affected fish showed external signs of severe November 2001, when water temperature was 21.5•Ž. emaciation including sunken eyes(enophthalmia),bony A preliminary observation showed that most of the ema ridges on the head and a tapered body(Tin Tun et al., ciated flounder(mean body length,25.8 cm;mean body 2000;Ogawa and Yokoyama,2001).By subsequent weight,150.3 g)were infected with enteric myxozoans. parasitological and molecular studies,three enteric In the present study, parasitological and molecular myxozoans,Enteromyxum fugu(=Myxidium fugu), analyses were conducted to identify the causative agent Enteromyxum leei(=Myxidium sp.TP)and Leptotheca (or agents)of flounder emaciation. In addition, fugu, were found from the intestine of diseased fish(Tin attempts of fish-to-fish transmission of the disease Tun et al.,2000;Yanagida et al.,2004; 2005).Subse among tiger puffer and Japanese flounder were carried quently, the latter two species were shown to be respon out. sible for the emaciation disease(Tin Tun et al.,2002). In recent years, a similar disease has been noticed Materials and Methods in Japanese flounder Paralichthys olivaceus farmed in Miyazaki Prefecture, Japan. Japanese flounder were Fish and disease diagnosis cultured in concrete tanks at a land-based site supplied Moribund cultured Japanese flounder(0-year-old; with flow-through sea water. The Japanese flounder mean body length,23.0 cm)were obtained from a com mercial fish farm located in Miyazaki Prefecture in Octo * Corresponding author ber2002.Following visual examination of symptoms, E-mail: [email protected] fish were dissected, and then the gut tissues were 176 H. Yasuda, T. Ooyama, A. Nakamura, K. Iwata, O. Palenzuela and H. Yokoyama excised. Fresh smears of intestinal scrapings were Transmission trial among Japanese flounder observed by light microscopy. Imprint slides of the As donor fish, three diseased Japanese flounder intestinal mucosa were prepared and stained with Diff (0-year-old; average body weight,241 g)were provided Quik (International Reagents Corp., Japan)for parasito- by the fish farm on January 6,2005.Myxosporean-free logical examination. For histology, pieces of the intesti juvenile Japanese flounder were purchased from a seed nal tissues were fixed in 10% buffeted formalin and production company and kept in acryl tanks(ca.140L) embedded in paraffin wax. Tissue sections(5ƒÊm) equipped with a closed re-circulating filtration system were stained with hematoxylin-eosin(H.E.)&Uvitex 2B, and a thermo-regulator adjusting the water temperature and observed by light or fluorescent microscopy.In to 23•Ž.Ten recipient Japanese flounder(average addition, the kidney was sampled and BHI agar plates total length,19.8 cm; average body weight,71.5g)were were inoculated for bacterial isolation. fed with pieces of the pooled chopped intestines(12.6g from the donors.While feeding the infected) gut tissue, Molecular analysis of myxozoan the filtration system of the tank was interrupted for one DNA cloning and sequencing of the parasite's small hour to guarantee the exposure.As a negative control, subunit ribosomal DNA gene(SSU rDNA)were done ten uninfected Japanese flounder(average total length, according to Palenzuela et al.(2002)and Yanagida et al. 19.8 cm; average body weight,71.9 g)were kept sepa (2004).Briefly, parasite DNA was extracted from rately in the same condition.All fish were fed daily with heavily infected intestinal mucosa scrapings using a commercial extruded pellet (EP).On 32 days PE,all commercial genomic DNA purification kit(Qiagen Gmbh, surviving fish were sampled.Following measurements Germany). Myxozoan nuclear SSU rDNA was ampli of body length, body weight and liver weight, the gut tis fied by PCR using the primers MM18Sf(ctggttgattctgcc sues were excised to examine for myxozoan infection as agtggtc)and MM18Sr (cggtactagcgacgggcg) (Palenzuela described above.In addition,Diff-Quik stained imprints et al.,2002).The products of two parallel reactions(20 were observed to evaluate semi-quantitatively the L each)were pooled and cleaned using a ƒÊspin-column progress of myxozoan development.The myxozoan cleanup kit(Qiagen).A subsample of the eluent was developmental stages within five visual fields under a checked for purity and concentration in an ethidium bro light microscope with a 400-fold magnification were mide-stained 1% agarose gel. The myxozoan product enumerated.All myxozoan plasmodia were classified was ligated into a cloning vector(pT7-Blue-T,Takara, into three stages; presporogonic,sporogonic and spore Japan)which was used to transform competent E.coli stages,and then their relative frequencies in appearance cells.Transformants were selected by the blue/white were recorded. screening method on plates containing ampicillin and X-Gal.Both DNA strands from two different clones Results were sequenced. Gross and bacteriological observations Transmission trial from Japanese flounder to tiger puffer Affected Japanese flounder showed external signs One emaciated Japanese flounder(0-year-old,353 of distended abdomen, rectal prolapse, sunken eyes and g)was obtained from the fish farm on May 23,2002,and a typical bony ridge on the skull(Fig. 1A).Ascites, served as a "donor fish".Myxosporean-free juvenile mucous liquid in the digestive tract and a flimsy intestinal tiger puffer(average body weight, 7.1g)were purchased wall were also evident.Occassionally,Edwardsiella from a seed production company and held in fiberglass tarda, the causative bacterium of edwardsiellosis, was reinforced plastics(FRP)tanks(1500 L)supplied with isolated from the kidney(about 20% of examined fish), flow-through filtered seawater in Miyazaki Prefectural but it was not found consistently in emaciated fish. Fisheries Experimental Station.The intestine of the donor fish was removed, weighed(1.6g)and finely Parasitological observation chopped.Fifty recipient tiger puffer were fed with Numerous myxozoans with different developmental this material, and they were subsequently sampled at stages were consistently detected both in fresh smears 23, 30,37and 44 days post-exposure(PE) (10fish and in Diff-Quik stained imprints of gut mucosa from per day except the final sampling when all survivors infected fish.In intestinal scrapings, trophozoites were sacrificed).Fifty tiger puffer from the same stock harboring one or two secondary cells exhibited a slow were kept as controls under equivalent conditions rotating and amoeboid movement on the spot.The Myxozoan infections were examined as described commonest stage in Diff-Quik stained intestinal imprints above. During the experimental period, the water tem was a pre-sporogonic plasmodium with a spherical pri perature ranged from 22 to 24•Ž.All fish were daily fed mary cell(10-20ƒÊm in diameter) having a pink nucleus with commercial pellets. and one or two deep blue secondary cells (Fig. 1B).Spore stages were rarely found and when present, they were mostly immature(Fig.1C).Spores Enteromyxum leei in Japanese flounder 177 Fig. 1. Myxosporean emaciation disease of Japanese flounder Paralichthys olivaceus. A: Gross appearance of affected Japanese flounder. Note a bony ridge on the skull. B: Developmental stages of Enteromyxum leei from Japanese flounder. Arrow and arrowhead show pre-sporogonic and sporogonic stages, respectively. Diff-Quik stain. Bar = 10 ƒÊm. C: An immature spore of E. leei observed in intestinal scraping. Bar = 10 ƒÊm. D & E: Histological sections of the infected intestine showing hyperplasia of the gut epithelium. H. E. stain. Bars = 50 ƒÊm. F: Histological section showing Uvitex 2B-positive E. leei parasitizing the gut epithelium. Uvitex 2B & H. E. stain. Double exposure with UV and normal light. Bar = 50 ƒÊm. were slightly spindle to crescent-shaped, measuring lium (Figs. 1D & 1E). Detachment and destruction of 15.6 (14-18) ƒÊm long and 8.8 (7-10) ƒÊm wide. Two the gut epithelia associated with proliferation of parasitic polar capsules with a size of 5.5 (4.5-6.5) ƒÊm long and stages were evident. It was noticed that plasmodia 2.7 (2-3) ƒÊm wide were elongated, tapered to their distal located in the gut epithelium were positive for Uvitex 2B ends and arranged obliquely in frontal view.
Load more

Recommended publications
  • Acquired Protective Immune Response in a Fish-Myxozoan Model
    Fish and Shellfish Immunology 90 (2019) 349–362 Contents lists available at ScienceDirect Fish and Shellfish Immunology journal homepage: www.elsevier.com/locate/fsi Full length article Acquired protective immune response in a fish-myxozoan model T encompasses specific antibodies and inflammation resolution Amparo Picard-Sánchez1, Itziar Estensoro1, Raquel del Pozo, M. Carla Piazzon, ∗ Oswaldo Palenzuela, Ariadna Sitjà-Bobadilla Fish Pathology Group, Instituto de Acuicultura Torre de la Sal (IATS-CSIC), Castellón, Spain ARTICLE INFO ABSTRACT Keywords: The myxozoan parasite Enteromyxum leei causes chronic enteritis in gilthead sea bream (GSB, Sparus aurata) Acquired immune response leading to intestinal dysfunction. Two trials were performed in which GSB that had survived a previous infection Fish IgM with E. leei (SUR), and naïve GSB (NAI), were exposed to water effluent containing parasite stages. Humoral Sparus aurata factors (total IgM and IgT, specific anti-E. leei IgM, total serum peroxidases), histopathology and gene expression Enteromyxum leei were analysed. Results showed that SUR maintained high levels of specific anti-E. leei IgM (up to 16 months), Parasite resistance expressed high levels of immunoglobulins at the intestinal mucosa, particularly the soluble forms, and were Gene expression resistant to re-infection. Their acquired-type response was complemented by other immune effectors locally and systemically, like cell cytotoxicity (high granzyme A expression), complement activity (high c3 and fucolectin expression), and serum peroxidases. In contrast to NAI, SUR displayed a post-inflammatory phenotype in the intestine and head kidney, characteristic of inflammation resolution (low il1β, high il10 and low hsp90α ex- pression). 1. Introduction causing different degrees of anorexia, delayed growth with weight loss, cachexia, reduced marketability and increased mortality [6].
    [Show full text]
  • Histopathological Changes Caused by Enteromyxum Leei Infection in Farmed Sea Bream Sparus Aurata
    Vol. 79: 219–228, 2008 DISEASES OF AQUATIC ORGANISMS Published May 8 doi: 10.3354/dao01832 Dis Aquat Org Histopathological changes caused by Enteromyxum leei infection in farmed sea bream Sparus aurata R. Fleurance1, C. Sauvegrain2, A. Marques3, A. Le Breton4, C. Guereaud1, Y. Cherel1, M. Wyers1,* 1Department of Veterinary Pathology, UMR 703 INRA/ENVN, Nantes Veterinary School, BP 40706, 44307 Nantes cedex 03, France 2Aquanord, Terre des marins, 59820 Gravelines, France 3DRIM Dept BEE, UM2, case 080 Université Montpellier, 34095 Montpellier cedex 5, France 4Fish Health Consultant, 31330 Grenade sur Garonne, France ABSTRACT: Histological examinations were carried out on the stomach, pyloric caeca and 4 differ- ent parts of the intestine, as well as the rectum, hepatopancreas, gall bladder and spleen of 52 sea bream Sparus aurata spontaneously infected by Enteromyxum leei. Fifteen fish from a non-infected farm were included as a control. Clinical signs appeared only in extensively and severely infected fish. We observed Enteromyxum leei almost exclusively in the intestinal tract, and very rarely in the intrahepatic biliary ducts or gall bladder. We observed heavily infected intestinal villi adjacent to par- asite-free villi. Histological changes indicated a parasite infection gradually extending from villus to villus, originating from an initial limited infected area probably located in the rectum. The parasite forms were exclusively pansporoblasts located along the epithelial basement membrane. Periodic acid-Schiff (PAS)–Alcian blue was the most useful histological stain for identifying the parasite and characterising the degree of intestinal infection. We observed severe enteritis in infected fish, with inflammatory cell infiltration and sclerosis of the lamina propria.
    [Show full text]
  • Diagnosis and Treatment of Multi-Species Fish Mortality Attributed to Enteromyxum Leei While in Quarantine at a US Aquarium
    Vol. 132: 37–48, 2018 DISEASES OF AQUATIC ORGANISMS Published December 11 https://doi.org/10.3354/dao03303 Dis Aquat Org Diagnosis and treatment of multi-species fish mortality attributed to Enteromyxum leei while in quarantine at a US aquarium Michael W. Hyatt1,5,*, Thomas B. Waltzek2, Elizabeth A. Kieran3,6, Salvatore Frasca Jr.3, Jan Lovy4 1Adventure Aquarium, Camden, New Jersey 08103, USA 2Wildlife & Aquatic Veterinary Disease Laboratory, University of Florida College of Veterinary Medicine, Gainesville, Florida 32611, USA 3Aquatic, Amphibian and Reptile Pathology Service, Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, Florida 32610, USA 4Office of Fish & Wildlife Health & Forensics, New Jersey Division of Fish & Wildlife, Oxford, New Jersey 07863, USA 5Present address: Wildlife Conservation Society, New York Aquarium, Brooklyn, NY 11224, USA 6Present address: Arizona Veterinary Diagnostic Laboratory, University of Arizona, Tucson, Arizona 85705, USA ABSTRACT: Enteromyxum leei is an enteric myxozoan parasite of fish. This myxozoan has low host specificity and is the causative agent of myxozoan emaciation disease, known for heavy mor- talities and significant financial losses within Mediterranean, Red Sea, and Asian aquaculture industries. The disease has rarely been documented within public aquaria and, to our knowledge, has never been confirmed within the USA. This case report describes an outbreak of E. leei in a population of mixed-species east African/Indo-Pacific marine fish undergoing quarantine at a public aquarium within the USA. Four of 16 different species of fish in the population, each of a different taxonomic family, were confirmed infected by the myxozoan through cloacal flush or intestinal wet mount cytology at necropsy.
    [Show full text]
  • A New Species of Myxidium (Myxosporea: Myxidiidae)
    University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln John Janovy Publications Papers in the Biological Sciences 6-2006 A New Species of Myxidium (Myxosporea: Myxidiidae), from the Western Chorus Frog, Pseudacris triseriata triseriata, and Blanchard's Cricket Frog, Acris crepitans blanchardi (Hylidae), from Eastern Nebraska: Morphology, Phylogeny, and Critical Comments on Amphibian Myxidium Taxonomy Miloslav Jirků University of Veterinary and Pharmaceutical Sciences, Palackého, [email protected] Matthew G. Bolek Oklahoma State University, [email protected] Christopher M. Whipps Oregon State University John J. Janovy Jr. University of Nebraska - Lincoln, [email protected] Mike L. Kent OrFollowegon this State and Univ additionalersity works at: https://digitalcommons.unl.edu/bioscijanovy Part of the Parasitology Commons See next page for additional authors Jirků, Miloslav; Bolek, Matthew G.; Whipps, Christopher M.; Janovy, John J. Jr.; Kent, Mike L.; and Modrý, David, "A New Species of Myxidium (Myxosporea: Myxidiidae), from the Western Chorus Frog, Pseudacris triseriata triseriata, and Blanchard's Cricket Frog, Acris crepitans blanchardi (Hylidae), from Eastern Nebraska: Morphology, Phylogeny, and Critical Comments on Amphibian Myxidium Taxonomy" (2006). John Janovy Publications. 60. https://digitalcommons.unl.edu/bioscijanovy/60 This Article is brought to you for free and open access by the Papers in the Biological Sciences at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in John Janovy Publications by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Authors Miloslav Jirků, Matthew G. Bolek, Christopher M. Whipps, John J. Janovy Jr., Mike L. Kent, and David Modrý This article is available at DigitalCommons@University of Nebraska - Lincoln: https://digitalcommons.unl.edu/ bioscijanovy/60 J.
    [Show full text]
  • In Vitro Studies on Viability and Proliferation of Enteromyxum Scophthalmi (Myxozoa), an Enteric Parasite of Cultured Turbot Scophthalmus Maximus
    DISEASES OF AQUATIC ORGANISMS Vol. 55: 133–144, 2003 Published July 8 Dis Aquat Org In vitro studies on viability and proliferation of Enteromyxum scophthalmi (Myxozoa), an enteric parasite of cultured turbot Scophthalmus maximus María J. Redondo, Oswaldo Palenzuela*, Pilar Alvarez-Pellitero Consejo Superior de Investigaciones Científicas, Instituto de Acuicultura Torre la Sal, 12595 Ribera de Cabanes, Castellón, Spain ABSTRACT: In vitro cultivation of the myxozoan Enteromyxum scophthalmi was attempted using dif- ferent culture media and conditions. The progress of the cultures was monitored using dye-exclusion viability counts, tetrazolium-based cell-proliferation assays, measuring the incorporation of BrdU during DNA synthesis, and by morphological studies using light and electron microscopes. In pre- liminary experiments, the persistence of viable stages for a few days was ascertained in both medium 199 (M199) and in seawater. An apparent initial proliferation was noticed in the culture media, with many young stages observed by Day 7 post-inoculation (p.i.). In contrast, fast degeneration occurred in seawater, with but a few living stages persisting to Day 1 p.i and none to Day 5 p.i. Both tetrazolium-based cell-proliferation assays and dye-exclusion viability counts demonstrated a pro- gressive degeneration of the cultures. Although M199 medium and neutral pH with the addition of sera appeared to provide the most favourable conditions during the first few hours, all cultures degenerated with time and no parasite proliferation or maintenance could be achieved in the long term in any of the conditions assayed, including attempts of co-cultivation with a turbot cell line. The ultrastructure of stages cultured for 15 d demonstrated complete degeneration of organelles and mitochondria, although the plasma membrane remained intact in many stages.
    [Show full text]
  • Effect of Epigallocatechin Gallate on Viability of Kudoa Septempunctata
    ISSN (Print) 0023-4001 ISSN (Online) 1738-0006 Korean J Parasitol Vol. 58, No. 5: 593-597, October 2020 ▣ BRIEF COMMUNICATION https://doi.org/10.3347/kjp.2020.58.5.593 Effect of Epigallocatechin Gallate on Viability of Kudoa septempunctata 1 2 1 1 2 1, Sang Phil Shin , Hyun Ki Hong , Chang Nam Jin , Hanchang Sohn , Kwang Sik Choi , Jehee Lee * 1Department of Marine Life Sciences & Marine Science Institute, Jeju National University, Jeju Self-Governing Province 63243, Korea; 2Department of Marine Life Science (BK FOUR) and Marine Science Institute, Jeju National University, Jeju Self-Governing Province 63243, Korea Abstract: Kudoa septempunctata have been reported as a causative agent for acute transient gastrointestinal troubles after eating raw olive flounder (Paralichthys olivaceus). It raised public health concerns and quarantine control in several countries. Quantitative evaluation on viability of K. septempunctata is crucial to develop effective chemotherapeutics against it. A cytometry using fluorescent stains was employed to assess effect of three compounds on viability of K. sep- tempunctata. Epigallocatechin gallate reduced markedly viability of K. septempunctata at 0.5 mM or more, and damaged K. septempunctata spores by producing cracks. Key words: Kudoa septempunctata, olive flounder, flow cytometry, epigallocatechin gallate Myxozoa (Cnidaria) include more than 2,100 species, most of [13,14]. However, any assay on the viability of the myxozoans which are coelozoic or histozoic parasites in fish [1]. Although was performed using flow cytometry. Aim of present study is most myxozoans do not cause a serious problem in fish, sever- to assay on effect of three chemicals compounds to the viability al species Enteromyxum leei, E.
    [Show full text]
  • First Report of Enteromyxum Leei (Myxozoa)
    魚病研究 Fish Pathology, 49 (2), 57–60, 2014. 6 © 2014 The Japanese Society of Fish Pathology Short communication Typical mature spores in the intestine and gall blad- der of infected fish were in an arcuate, almost semicircu- First Report of Enteromyxum leei lar shape (Fig. 1B–D). Polar capsules were elongated, (Myxozoa) in the Black Sea in a tapering to their distal ends, open at one side of the spore, diverging at an angle of about 90°. Polar Potential Reservoir Host filaments coiled 7 times on average (range 6–8). Chromis chromis Spore and polar capsule dimensions are provided in Table 1. Based on the overall morphology and spore dimentions, the parasite was identified as a myxozoan, Ahmet Özer*, Türkay Öztürk, Hakan Özkan Enteromyxum leei. and Arzu Çam The phylum Myxozoa is composed entirely of endo- parasites, including some that cause diseases which Sinop University, Faculty of Fisheries and Aquatic substantial impact on aquaculture and fisheries around Sciences, 57000 Sinop, Turkey the world (Kent et al., 2001). Myxosporean infection occurs in a wide range of both marine and freshwater (Received January 25, 2014) fish species. Some reviews have stressed the impor- tance of those species that are associated with pathol- ogy in mariculture (Alvarez-Pellitero and Sitjà-Bobadilla, ABSTRACT—Damselfish Chromis chromis collected from 1993; Alvarez-Pellitero et al., 1995) and in freshwater the Black Sea coasts of Sinop, Turkey, were examined for farming (El-Matbouli et al., 1992). Enteromyxum leei is myxosporeans in June and July 2013. One of 25 healthy certainly one species of such concern. To our knowl- fish and 2 dead fish had infections with Enteromyxum leei.
    [Show full text]
  • Studies on Transmission and Life Cycle of Enteromyxum Scophthalmi (Myxozoa), an Enteric Parasite of Turbot Scophthalmus Maximus
    FOLIA PARASITOLOGICA 51: 188–198, 2004 Studies on transmission and life cycle of Enteromyxum scophthalmi (Myxozoa), an enteric parasite of turbot Scophthalmus maximus María J. Redondo, Oswaldo Palenzuela and Pilar Alvarez-Pellitero Instituto de Acuicultura de Torre de la Sal (CSIC), Ribera de Cabanes, 12595 Castellón, Spain Key words: Myxozoa, Myxosporea, Enteromyxum, life cycle, transmission, turbot, intestinal explants, in vitro Abstract. In order to elucidate the transmission and dispersion routes used by the myxozoan parasite Enteromyxum scophthalmi Palenzuela, Redondo et Alvarez-Pellitero, 2002 within its host (Scophthalmus maximus L.), a detailed study of the course of natural and experimental infections was carried out. Purified stages obtained from infected fish were also used in in vitro assays with explants of uninfected intestinal epithelium. The parasites can contact and penetrate loci in the intestinal epithelium very quickly. From there, they proliferate and spread to the rest of the digestive system, generally in an antero-posterior pattern. The dispersion routes include both the detachment of epithelium containing proliferative stages to the intestinal lumen and the breaching of the subepithelial connective system and local capillary networks. The former mechanism is also responsible for the release of viable proliferative stages to the water, where they can reach new fish hosts. The finding of parasite stages in blood smears, haematopoietic organs, muscular tissue, heart and, less frequently, skin and gills, suggests the existence of additional infection routes in transmission, especially in spontaneous infections, and indicates the role of vascular system in parasite dispersion within the fish. The very high virulence of this species in turbot and the rare development of mature spores in this fish may suggest it is an accidental host for this parasite.
    [Show full text]
  • AN ABSTRACT of the DISSERTATION of Damien E
    AN ABSTRACT OF THE DISSERTATION OF Damien E. Barrett for the degree of Doctor of Philosophy in Microbiology presented on September 17, 2020. Title: What Makes a Fish Resistant? Comparative Genomics and Transcriptomics of Oncorhynchus mykiss with Differential Resistance to the Parasite Ceratonova shasta Abstract approved: ______________________________________________________ Jerri L. Bartholomew The myxozoan Ceratonova shasta is an intestinal parasite of salmon and trout that causes ceratomyxosis, a disease characterized by severe inflammation of the intestine that can lead to hemorrhaging, necrosis, and death of the fish host. The parasite is endemic to the Pacific Northwest of the United States and Canada, where it has been linked to the decline of wild fish stocks. The parasite exerts a strong selective force on its fish host, and fish populations from C. shasta endemic watersheds become genetically fixed for resistance to ceratomyxosis. This contrasts with fish from watersheds where the parasite is not established, who are highly susceptible the disease, with a single spore capable of causing a lethal infection. Management of the disease relies on selective stocking of resistant fish, however, even these fish can succumb to the infection. Understanding the genetic and immunological basis of resistance to this disease would provide the framework for the development of therapeutics and identification of genetic markers that could be used in selective breeding. In this project, we employed a comparative transcriptomics and genomics approach to understand how resistant and susceptible strains of Oncorhynchus mykiss (rainbow trout/steelhead) respond to C. shasta infection and identify the genomic loci conferring resistance. We found that infection by C.
    [Show full text]
  • Disease of Aquatic Organisms 89:209
    Vol. 89: 209–221, 2010 DISEASES OF AQUATIC ORGANISMS Published April 9 doi: 10.3354/dao02202 Dis Aquat Org OPEN ACCESS Light and electron microscopic studies on turbot Psetta maxima infected with Enteromyxum scophthalmi: histopathology of turbot enteromyxosis R. Bermúdez1,*, A. P. Losada2, S. Vázquez2, M. J. Redondo3, P. Álvarez-Pellitero3, M. I. Quiroga2 1Departamento de Anatomía y Producción Animal and 2Departamento de Ciencias Clínicas Veterinarias, Facultad de Veterinaria, Universidad de Santiago de Compostela, 27002 Lugo, Spain 3Instituto de Acuicultura de Torre la Sal, Consejo Superior de Investigaciones Científicas, 12595 Ribera de Cabanes, Castellón, Spain ABSTRACT: In the last decade, a new parasite that causes severe losses has been detected in farmed turbot Psetta maxima (L.), in north-western Spain. The parasite was classified as a myxosporean and named Enteromyxum scophthalmi. The aim of this study was to characterize the main histological changes that occur in E. scophthalmi-infected turbot. The parasite provoked catarrhal enteritis, and the intensity of the lesions was correlated with the progression of the infection and with the develop- ment of the parasite. Infected fish were classified into 3 groups, according to the lesional degree they showed (slight, moderate and severe infections). In fish with slight infections, early parasitic stages were observed populating the epithelial lining of the digestive tract, without eliciting an evident host response. As the disease progressed, catarrhal enteritis was observed, the digestive epithelium showed a typical scalloped shape and the number of both goblet and rodlet cells was increased. Fish with severe infections suffered desquamation of the epithelium, with the subsequent release of par- asitic forms to the lumen.
    [Show full text]
  • In Common Carp: a Pilot Study
    pathogens Article Natural Feed Additives Modulate Immunity and Mitigate Infection with Sphaerospora molnari (Myxozoa: Cnidaria) in Common Carp: A Pilot Study Vyara O. Ganeva 1, Tomáš Korytáˇr 1,2, Hana Pecková 1, Charles McGurk 3, Julia Mullins 3, Carlos Yanes-Roca 2, David Gela 2, Pavel Lepiˇc 2, Tomáš Policar 2 and Astrid S. Holzer 1,* 1 Biology Center of the Czech Academy of Sciences, Institute of Parasitology, 37005 Ceskˇ é Budˇejovice, Czech Republic; [email protected] (V.O.G.); [email protected] (T.K.); [email protected] (H.P.) 2 South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Faculty of Fisheries and Protection of Waters, University of South Bohemia, 37005 Ceskˇ é Budˇejovice,Czech Republic; [email protected] (C.Y.-R.); [email protected] (D.G.); [email protected] (P.L.); [email protected] (T.P.) 3 Skretting Aquaculture Research Centre, 4016 Stavanger, Norway; [email protected] (C.M.); [email protected] (J.M.) * Correspondence: [email protected]; Tel.: +420-38777-5452 Received: 26 October 2020; Accepted: 28 November 2020; Published: 2 December 2020 Abstract: Myxozoans are a diverse group of cnidarian parasites, including important pathogens in different aquaculture species, without effective legalized treatments for fish destined for human consumption. We tested the effect of natural feed additives on immune parameters of common carp and in the course of a controlled laboratory infection with the myxozoan Sphaerospora molnari. Carp were fed a base diet enriched with 0.5% curcumin or 0.12% of a multi-strain yeast fraction, before intraperitoneal injection with blood stages of S.
    [Show full text]
  • A Review of Toxins from Cnidaria
    marine drugs Review A Review of Toxins from Cnidaria Isabella D’Ambra 1,* and Chiara Lauritano 2 1 Integrative Marine Ecology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy 2 Marine Biotechnology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy; [email protected] * Correspondence: [email protected]; Tel.: +39-081-5833201 Received: 4 August 2020; Accepted: 30 September 2020; Published: 6 October 2020 Abstract: Cnidarians have been known since ancient times for the painful stings they induce to humans. The effects of the stings range from skin irritation to cardiotoxicity and can result in death of human beings. The noxious effects of cnidarian venoms have stimulated the definition of their composition and their activity. Despite this interest, only a limited number of compounds extracted from cnidarian venoms have been identified and defined in detail. Venoms extracted from Anthozoa are likely the most studied, while venoms from Cubozoa attract research interests due to their lethal effects on humans. The investigation of cnidarian venoms has benefited in very recent times by the application of omics approaches. In this review, we propose an updated synopsis of the toxins identified in the venoms of the main classes of Cnidaria (Hydrozoa, Scyphozoa, Cubozoa, Staurozoa and Anthozoa). We have attempted to consider most of the available information, including a summary of the most recent results from omics and biotechnological studies, with the aim to define the state of the art in the field and provide a background for future research. Keywords: venom; phospholipase; metalloproteinases; ion channels; transcriptomics; proteomics; biotechnological applications 1.
    [Show full text]