DOCSLIB.ORG

STUDIES on the CHARACTERISATION and DETECTION of Piscirickettsia Salmonis By

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

STUDIES ON THE CHARACTERISATION AND DETECTION OF Piscirickettsia salmonis By Sema Yuksel BSc Aquaculture, MSc Living Marine Resources Thesis submitted for the degree of Doctor of philosophy University of Stirling 2003 To Tayfun and my family for their endless love and support DECLARATION I hereby declare that this thesis has been composed entirely by myself and is the result of my own investigations. It has not been previously submitted or accepted for any other degrees. Serna Yuksel I ACKNOWLEDMENTS I would like to express my sincere gratitude to the following people for their contribution in the completion of this thesis. First of all, I would like deeply thank to my supervisors, Dr. Kimberly D. Thompson, Dr. Alexandra Adams and Dr. Anthony Ellis, for their continuing support, encouragement, valuable guidance, endless help and kindness throughout the period of my study. My special gratitude is given everyone in Institute of Aquaculture who provided valuable help and advise through these studies, especially to Miss Fiona Muir, Mr. Linton Brown, Dr. Margaret Caimey, Dr. John Taggart, Prof. Hugh W. Ferguson, Dr. William Starkey, Mr. Richard Collins, Mrs. Gillian Dreczkowski, Dr. Janet A. O’Flynn, Dr. David John Morris, Mr. Iain Elliot, Mrs. Debbie Faichney, Mrs. Maureen Menzies, Mrs. Hilary McEwan, Mrs. Karen Snedden, Mr. Stuart D. Millar, Dr. Marianne D. Pearson, Mr. James Dick, Mr. Alan Porter , Mr. Niale Avchinachie and Dr. Ruth Campell. Also many thanks to everyone at the Animal House Unit. I would like also thank to Dr. Roy Palmer and everyone in Aquatic Veterinary Group, National Diagnostics Centre, University of College Ireland for their valuable time to help me learn the cell culture techniques and IFAT. Many thanks to everyone in FRS Marine Laboratory in Aberdeen for their help in carrying out the experimental challenges, especially to Mr. Benjamin E. Williamson in Behaviour and Aquarium Services. Many special thanks go to all of my friends for being supportive and for making my time in Stirling memorable, especially to Emine Turgut, Nirattisai Petchsupa, David Miles, Ioannis Vatsos, Nelly Isyagi, James Neary, Suppalak Puttinaowarat, Md. Ali Reza Faruk, Manual Fuentes, Nick Taylor and all my housemates in Fairview. My love goes to my husband Tayfun Yuksel. Thanks for his endless love, support and patience. Many special thanks to my family for being supportive and always being there for me. I am truly indebted to Turkish Government and Aquaculture Vaccines Limited (AVL) for providing financial support for my studies. II ABSTRACT Piscirickettsia salmonis, the aetiological agent of piscirickettsiosis, has recently been responsible for significant disease outbreaks in a variety of economically important freshwater and seawater fish species cultured worldwide. The development of effective control strategies for the disease has been limited due to a lack of knowledge about the physiology, intracellular growth, transmission and pathogenesis of the organism. It is also notknown how P. salmonis isolates differ when isolated from different locations and from different fish species. The aim of the present study was to characterise phenotypic and serological differences between various P. salmonis isolates. The growth of these isolates in vitro was also examined together with their virulence and their pathogenesis. The antibody response of fish to live and killed P. salmonis was examined in an attempt to understand the antigenicity of the organism, and various diagnostic techniques were developed as a means of controlling the disease. A simple and effective method for the purification of P. salmonis from fish cells to examine the antigenic properties of P. salmonis was developed. P. salmonis purified using differential pelleting and 30% Percoll (v/v) gradient gave yields with the highest purity and the highest infectivity. Fish cell lines were used to examine growth characteristics of P. salmonis isolates in vitro. It appears that P. salmonis has a 3-5 days (d) lag-phase and an 8 d log-phase of exponential growth in CHSE-214 cells. When the susceptibility of different fish cell lines to different P. salmonis isolates were compared, the highest TCID50 ml-1 was obtained in CHSE- 214, SHK-1 and EPC cells. The antigenic structure of the ten P. salmonis isolates was analysed using SDS-PAGE. P. salmonis isolates shared many bands but did appear to have differences in the low molecular weight regions of their profiles. Silver staining of Proteinase-K digested P. salmonis isolates showed that all isolates contained carbohydrate moieties below 30 kDa. Further characterisation of these was performed using a glycoprotein determination kit and a number of different biotin-labelled lectins. The SDS-PAGE profile of isolate R-29 appeared different when passaged three times through fish cell lines. The bacteria grown in CHSE-214, EPC and SBL cells, which showed a higher susceptibility to the bacterium, had more material in the lower region of the gel than bacteria recovered from less susceptible BF-2 and RTG-2 cells where the bands in this region had disappeared. A nested polymerase chain reaction (N-PCR) was used to differentiate different P. salmonis isolates. Isolate R-29 was the only isolate which resulted in a PCR product different to that of the other isolates examined. Ill A whole cell preparation of purified P. salmonis (type strain LF-89) was used to prepare a rabbit polyclonal antibody and six monoclonal antibodies. These antibody probes were used to compare the antigenicity between P. salmonis isolates. Major antigens of P. salmonis were observed at 95, 72, 60, 36, 32 and 20 kDa in Western blot (WB) analysis. The antibodies were also used to develop a variety of antibody-based tests for the more specific determination of the pathogen. A number of staining methods was also tried in an attempt to establish a rapid diagnostic method for piscirickettsiosis. The virulence of P. salmonis isolates was compared in an experimental infection of Atlantic salmon. It was possible to re-isolate the bacterium from infected kidney tissue during the first 4 weeks post-inoculation (wpi) and to detect by ELISA in the kidney of fish sampled 8 wpi. The histopathology observed was similar to that seen during natural outbreaks of piscirickettsiosis. No obvious difference was seen in the pathology between the different isolates used in the experimental infection. Atlantic salmon were immunised with heat-killed preparation of various P. salmonis isolates. The highest antibody response was obtained in sera raised against P. salmonis isolate R-29. This was also found to be the case in fish infected with live R-29 compared with other P. salmonis isolates. Sera from fish either challenged with live bacteria or immunised with heat-killed bacteria were examined in WB analysis. Proteins between 30-60 kDa appeared to be recognised with sera raised against live P. salmonis, unlike the sera raised against heat-killed P. salmonis, except for a strong reaction with the band seen at 60 kDa with sera from fish immunised with isolate R-29. Other bands at 95,72 and 20 kDa were recognised by the fish sera raised against either heat-killed P. salmonis or the live bacteria. For the first time, phage particles were observed to be associated with rickettsia infecting fish. Attempts were made to identify and characterise the phages in this study with a view to using them in the control of P. salmonis. The significance of the characterisation of P. salmonis isolates and the development of tests to detect and identify the pathogen carried out in this study is discussed within this thesis, together with further research which may lead to the development of successful control strategies for piscirickettsiosis. IV ABBREVIATIONS Mg Microgram /il Microlitre ¡im Micrometre /¿M Micromolar 16S rDNA 16 small subunit ribosomal deoxyribonucleic acid 16S rRNA 16 small subunit ribosomal ribonucleic acid 23 S rDNA 23 large subunit ribosomal deoxyribonucleic acid 23S rRNA 23 large subunit ribosomal ribonucleic acid ABP Avidin-biotin-peroxidase complex ATCC American Tissue Culture Collection bp Base pair BF-2 Bluegill, Lepomus macrochirus Rafinesque fry cell line BSA Bovine serum albumine BS-1 Bandeiraea simplicifolia CHSE-214 Chinook salmon, Oncorhynchus tshawytscha embryo cell line Con A Jack bean (Canavalia ensiformes) CPE Cytopathic effect cpm Count per minute CSS Chromogenic substrate solution CTA Coral tree (Erythrina cristagalli) d Days DBI Dot blot immunobinding assay dpi Days post-inoculation dpif Days post-infection DMDS Diatrizoate meglumine and diatrizoate sodium DMEM Dulbecco’s Modified Eagle’s Medium DMSO Dimethyl sulfoxide DNA Deoxyribonucleic acid EDTA Ethylenediaminetetraacetic acid ELISA Enzym-linked immunosorbent assay EM Electron microscopy EPC Epithelioma papulosum cyprini Cyprinus carpió cell line FAT Fluorescent antibody technique V FBS : Foetal bovine serum FCS : Foetal calf serum FITC : Fluorescein isothiocyanate h : Hours HAT : Hypoxanthine aminopterin thymidine media supplement H&E : Haematoxylin and Eosin HGA : Horse gram (Dolichos biflorus) HRP : Horseradish peroxidase HSWB : High salt wash buffer Hsp : Heat shock protein IFAT : Indirect fluorescent antibody technique ICU : Infected cell counting units IgG : Immunoglobulin G IGS : Immuno-gold staining m e : Immunohistochemistry M : Intramuscular IOA : Institute of Aquaculture, University of Stirling IP : Intraperitoneal US : Internal transcribed spacer IU : International units IV : Intravaneous kbp : Kilo base
Recommended publications
  • Metabolic and Genetic Basis for Auxotrophies in Gram-Negative Species

    Metabolic and Genetic Basis for Auxotrophies in Gram-Negative Species

    Metabolic and genetic basis for auxotrophies in Gram-negative species Yara Seifa,1 , Kumari Sonal Choudharya,1 , Ying Hefnera, Amitesh Ananda , Laurence Yanga,b , and Bernhard O. Palssona,c,2 aSystems Biology Research Group, Department of Bioengineering, University of California San Diego, CA 92122; bDepartment of Chemical Engineering, Queen’s University, Kingston, ON K7L 3N6, Canada; and cNovo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Lyngby, Denmark Edited by Ralph R. Isberg, Tufts University School of Medicine, Boston, MA, and approved February 5, 2020 (received for review June 18, 2019) Auxotrophies constrain the interactions of bacteria with their exist in most free-living microorganisms, indicating that they rely environment, but are often difficult to identify. Here, we develop on cross-feeding (25). However, it has been demonstrated that an algorithm (AuxoFind) using genome-scale metabolic recon- amino acid auxotrophies are predicted incorrectly as a result struction to predict auxotrophies and apply it to a series of the insufficient number of known gene paralogs (26). Addi- of available genome sequences of over 1,300 Gram-negative tionally, these methods rely on the identification of pathway strains. We identify 54 auxotrophs, along with the corre- completeness, with a 50% cutoff used to determine auxotrophy sponding metabolic and genetic basis, using a pangenome (25). A mechanistic approach is expected to be more appropriate approach, and highlight auxotrophies conferring a fitness advan- and can be achieved using genome-scale models of metabolism tage in vivo. We show that the metabolic basis of auxotro- (GEMs). For example, requirements can arise by means of a sin- phy is species-dependent and varies with 1) pathway structure, gle deleterious mutation in a conditionally essential gene (CEG), 2) enzyme promiscuity, and 3) network redundancy.
  • Yersinia Ruckeri Sp. Nov., the Redmouth (RM) Bacterium

    Yersinia Ruckeri Sp. Nov., the Redmouth (RM) Bacterium

    0020-7713/78/0028-0037$02-00/0 INTERNATIONALJOURNAL OF SYSTEMATICBACTERIOLOGY, Jan. 1978, p. 37-44 Vol. 28, No. 1 Copyright 0 1978 International Association of Microbiological Societies Printed in U.S. A. Yersinia ruckeri sp. nov., the Redmouth (RM) Bacterium W. H. EWING,? A. J. ROSS,?t DON J. BRENNER,??? AND G. R. FANNING Division of Biochemistry, Walter Reed Army Institute of Research, Washington, D.C. 20012 Cultures of the redmouth (RM) bacterium, one of the etiological agents of redmouth disease in rainbow trout (Salmo gairdneri) and certain other fishes, were characterized by means of their biochemical reactions, by deoxyribonucleic acid (DNA) hybridization, and by determination of guanine-plus-cytosine(G+C) ratios in DNA. The DNA relatedness studies confirmed the fact that the RM bacteria are members of the family Enterobacteriaceae and that they comprise a single species that is not closely related to any other species of Enterobacteri- aceae. They are about 30% related to species of both Serratia and Yersinia. A comparison of the biochemical reactions of RM bacteria and serratiae indicated that there are many differences between these organisms and that biochemically the RM bacteria are most closely related to yersiniae. The G+C ratios of RM bacteria were approximated to be between 47.5 and 48.5% These values are similar to those of yersiniae but markedly different from those of serratiae. On the basis of their biochemical reactions and their G+C ratios, the RM bacteria are considered to be a new species of Yersinia, for which the name Yersinia ruckeri is proposed.
  • Piscirickettsiosis and Piscirickettsia Salmonis in Fish: a Review

    Piscirickettsiosis and Piscirickettsia Salmonis in Fish: a Review

    Journal of Fish Diseases 2014, 37, 163–188 doi:10.1111/jfd.12211 Review Piscirickettsiosis and Piscirickettsia salmonis in fish: a review M Rozas1,2 and R Enrıquez3 1 Faculty of Veterinary Sciences, Graduate School, Universidad Austral de Chile, Valdivia, Chile 2 Laboratory of Fish Pathology, Pathovet Ltd., Puerto Montt, Chile 3 Laboratory of Aquatic Pathology and Biotechnology, Faculty of Veterinary Sciences, Animal Pathology Institute, Universidad Austral de Chile, Valdivia, Chile prevention of and treatment for piscirickettsiosis Abstract are discussed. The bacterium Piscirickettsia salmonis is the aetio- Keywords: control, epidemiology, pathogenesis, logical agent of piscirickettsiosis a severe disease pathology, Piscirickettsia salmonis, piscirickettsiosis, that has caused major economic losses in the transmission. aquaculture industry since its appearance in 1989. Recent reports of P. salmonis or P. salmonis-like organisms in new fish hosts and geographical regions have increased interest in the bacterium. Introduction Because this gram-negative bacterium is still poorly understood, many relevant aspects of its Piscirickettsia salmonis was the first rickettsia-like life cycle, virulence and pathogenesis must be bacterium to be known as a fish pathogen (Fryer investigated before prophylactic procedures can be et al. 1992). Since the first reports of pisciricketts- properly designed. The development of effective iosis in Chile at the end of the 1980s, Piscirickett- control strategies for the disease has been limited sia-like bacteria have been frequently recognized due to a lack of knowledge about the biology, in various fish species farmed in fresh water and intracellular growth, transmission and virulence of sea water and have significantly affected the pro- the organism. Piscirickettsiosis has been difficult ductivity of aquaculture worldwide (Mauel & to control; the failure of antibiotic treatment is Miller 2002).
  • International Response to Infectious Salmon Anemia: Prevention, Control, and Eradication: Proceedings of a Symposium; 3Ð4 September 2002; New Orleans, LA

    International Response to Infectious Salmon Anemia: Prevention, Control, and Eradication: Proceedings of a Symposium; 3Ð4 September 2002; New Orleans, LA

    United States Department of Agriculture International Response Animal and Plant Health to Infectious Salmon Inspection Service Anemia: Prevention, United States Department of the Interior Control, and Eradication U.S. Geological Survey United States Department of Commerce National Marine Fisheries Service Technical Bulletin No. 1902 The U.S. Departments of Agriculture (USDA), the Interior (USDI), and Commerce prohibit discrimination in all their programs and activities on the basis of race, color, national origin, sex, religion, age, disability, political beliefs, sexual orientation, or marital or family status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA’s TARGET Center at (202) 720–2600 (voice and TDD). To file a complaint of discrimination, write USDA, Director, Office of Civil Rights, Room 326–W, Whitten Building, 1400 Independence Avenue, SW, Washington, DC 20250–9410 or call (202) 720–5964 (voice and TDD). USDA, USDI, and Commerce are equal opportunity providers and employers. The opinions expressed by individuals in this report do not necessarily represent the policies of USDA, USDI, or Commerce. Mention of companies or commercial products does not imply recommendation or endorsement by USDA, USDI, or Commerce over others not mentioned. The Federal Government neither guarantees nor warrants the standard of any product mentioned. Product names are mentioned solely to report factually on available data and to provide specific information. Photo credits: The background illustration on the front cover was supplied as a photo micrograph by Michael Opitz, of the University of Maine, and is reproduced by permission.
  • 1.2.13 Piscirickettsiosis - 1

    1.2.13 Piscirickettsiosis - 1

    1.2.13 Piscirickettsiosis - 1 1.2.13 Piscirickettsiosis Marcia L. House and John L. Fryer Center for Salmon Disease Research Department of Microbiology Oregon State University Corvallis, OR 97331-3804 [email protected] [email protected] A. Name of Disease and Etiological Agent 1. Name of Disease Piscirickettsiosis, salmonid rickettsial septicemia, coho salmon septicemia, and Huito disease. 2. Etiological Agent Piscirickettsia salmonis This organism is an intracellular rickettsial-like pathogen of fish that replicates within membrane- bound cytoplasmic vacuoles of infected cells. The bacterium is fastidious and does not grow on any known artificial media. It is distantly related to the genera Coxiella and Francisella, and is grouped with the gamma subdivision of the proteobacteria. J. L. Fryer and C. N. Lannan have suggested this bacterium be included in a new family Piscirickettsiaceae and the proposal for the family with the formal description will appear in volume 2, second edition of Bergey’s Manual of Systematic Bacteriology (expected publication date in 2002). B. Known Geographical Range and Host Species of the Disease 1. Geographical Range Isolated from salmonid fish in Chile, Ireland, Norway, and both the west and east coasts of Canada. 2. Host Species Piscirickettsiosis has been observed in or isolated from coho salmon (Oncorhynchus kisutch), chinook salmon (O. tshawytscha), sakura salmon (O. masou), rainbow trout (O. mykiss), pink salmon (O. gorbuscha), and Atlantic salmon (Salmo salar). Coho salmon appear most susceptible. Other species of fish may also be susceptible to this bacterium. August 2001 1.2.13 Piscirickettsiosis - 2 C. Epizootiology Piscirickettsiosis was initially described in 1989 from infected salmonids in Chile.
  • Mouse Anti-Bacteria Yersinia Ruckeri Monoclonal Antibody, Clone 8G6/G7 (DMAB6804) This Product Is for Research Use Only and Is Not Intended for Diagnostic Use

    Mouse Anti-Bacteria Yersinia Ruckeri Monoclonal Antibody, Clone 8G6/G7 (DMAB6804) This Product Is for Research Use Only and Is Not Intended for Diagnostic Use

    Mouse anti-Bacteria Yersinia Ruckeri Monoclonal antibody, clone 8G6/G7 (DMAB6804) This product is for research use only and is not intended for diagnostic use. PRODUCT INFORMATION Product Overview Mouse anti-bacteria yersinia ruckeri monoclonal antibody. Yersinia Ruckeri IgG fraction obtained by immunizing mice with five Chilean isolates of Yersinia ruckeri (whole bacterial cells). The IgG fraction was purified using Protein G-Sepharose. Antigen Description Y. ruckeri is a Gram-negative, rod-shaped bacterium that shows a variable motility due to the presence of flagella. These flagella are not always observed. It is the causative agent of enteric redmouth disease (ERM) which is characterized by a chronic or acute enterosepticemia with high morbidity and mortality rates in salmonids and non-salmonids species. Six serovars have been described according to whole-cell serological typing. Isotype IgG2b Source/Host Mouse Clone 8G6/G7 Conjugate Unconjugated Applications ELISA, WB, IF Stability Stable at least one year at -20oC. Avoid repeated freezing and thawing. Format Solution at 1.0 mg/ml in PBS. Size 100 μg Preservative None Storage Store at -20ºC. BACKGROUND Introduction Yersinia is a genus of bacteria in the family Enterobacteriaceae. Yersinia are Gram-negative rod shaped bacteria, a few micrometers long and fractions of a micrometer in diameter, and are facultative anaerobes. Some members of Yersinia are pathogenic in humans; in particular, Y. 45-1 Ramsey Road, Shirley, NY 11967, USA Email: [email protected] Tel: 1-631-624-4882 Fax: 1-631-938-8221 1 © Creative Diagnostics All Rights Reserved pestis is the causative agent of the plague.
  • Unraveling the Biotechnological Potential of the Secretome of Burkholderia Cepacia Complex, with Focus on Its Antimicrobial Activity

    Unraveling the Biotechnological Potential of the Secretome of Burkholderia Cepacia Complex, with Focus on Its Antimicrobial Activity

    Unraveling the biotechnological potential of the secretome of Burkholderia cepacia complex, with focus on its antimicrobial activity Carina Andreia Ribeiro Galhofa Thesis to obtain the Master of Science Degree in Biotechnology Supervisors: Prof. Doctor Isabel Maria de Sá Correia Leite de Almeida; Doctor Patrick de Oliveira Freire Examination Committee Chairperson: Doctor Arsénio do Carmo Sales Mendes Fialho Supervisor: Prof. Doctor Isabel Maria de Sá Correia Leite de Almeida Members of the Committee: Doctor Inês Batista Guinote December 2017 Acknowledgements The wish to become a future microbiologist and to study the “little bugs” that were able to cause diseases in individuals way bigger than them has been present since I was a child. As such, I would like to acknowledge those that helped me from the beginning to the end of this work, making this possible. To Prof. Dr.Isabel Sá Correia, I would like to express my gratitude not only for advising, but also for accepting me in this project which I enjoyed to do so much. To Dr. Patrick Freire, my advisor within BioMimetx, not only for all the guidance and patience but, most of all, for the motivation and believing in my work and Dr. Carla Coutinho for the support, for bearing my inexperience and for all the tips given that prevented me from exploding the laboratory…and the centrifuge. To the funding of IBB (Institute for Bioengineering and Biosciences) and BioMimetx, that gave me all the resources and conditions that enabled the conduction of my work. To Amir Hassan, for staying up late at the lab waiting for me to finish my work and for the “Goooooodddd woooorkkkkk” motivational screams.
  • A Further Characterization of Yersinia Ruckeri (Enteric Redmouth Bacterium)

    A Further Characterization of Yersinia Ruckeri (Enteric Redmouth Bacterium)

    ‹›•aŒ¤‹† Fish Pathology 14 (2) 71-78, 1979. 9 A further Characterization of Yersinia ruckeri (Enteric Redmouth Bacterium) P. J. O'LEARY, J. S. ROHOVEC and J. L. FRYER Department of Microbiology, Oregon State University, Corvallis, OR 97331 (Received May 22, 1979) Seventeen cultures of Enteric Redmouth Bacterium were examined biochemically at selected temperatures. Incubation temperature altered the motility of the bacterium. At 9•Ž non functional peritrichous flagella were produced, while at 18, 22, and 27•Ž the bacterium was motile. The cells were nonmotile at 37•Ž due to a lack of flagellar production. The percent guanine plus cytosine was determined to be 47.95•}0.45 (P=0.05). This work supports the proposal of Yersinia ruckeri as the genus and species designation of the Entric Redmouth Bacterium. hynchus tshawytscha) and coho (O. kisutch) Introduction salmon, and rainbow trout (Salmo gairdneri). In the early 1950's, Rucker isolated a gram Each isolate was stored on Brain Heart In- negative, oxidase negative, motile bacterium fusion (BHI: Difco) slants under sterile mineral from moribund rainbow trout (Salmo gaird oil. neri). The first publication concerning this Biochemical tests bacterium did not appear until 1966 (Ross et The methods used to study most of the al., 1966) in which the definitive taxonomic biochemical properties of this organism have position of the bacterium could not be defined, been described previously (EDWARDSand EWING although it was placed in the family Entero 1972; LENETTE et al., 1974). For carbohydrate bacteriaceae. Hence the name Enteric Red utilization tests, sugars were incorporated into mouth Bacterium (ERMB) arose.
  • Scientific Opinion

    Scientific Opinion

    SCIENTIFIC OPINION ADOPTED: 29 April 2021 doi: 10.2903/j.efsa.2021.6651 Role played by the environment in the emergence and spread of antimicrobial resistance (AMR) through the food chain EFSA Panel on Biological Hazards (BIOHAZ), Konstantinos Koutsoumanis, Ana Allende, Avelino Alvarez-Ord onez,~ Declan Bolton, Sara Bover-Cid, Marianne Chemaly, Robert Davies, Alessandra De Cesare, Lieve Herman, Friederike Hilbert, Roland Lindqvist, Maarten Nauta, Giuseppe Ru, Marion Simmons, Panagiotis Skandamis, Elisabetta Suffredini, Hector Arguello,€ Thomas Berendonk, Lina Maria Cavaco, William Gaze, Heike Schmitt, Ed Topp, Beatriz Guerra, Ernesto Liebana, Pietro Stella and Luisa Peixe Abstract The role of food-producing environments in the emergence and spread of antimicrobial resistance (AMR) in EU plant-based food production, terrestrial animals (poultry, cattle and pigs) and aquaculture was assessed. Among the various sources and transmission routes identified, fertilisers of faecal origin, irrigation and surface water for plant-based food and water for aquaculture were considered of major importance. For terrestrial animal production, potential sources consist of feed, humans, water, air/dust, soil, wildlife, rodents, arthropods and equipment. Among those, evidence was found for introduction with feed and humans, for the other sources, the importance could not be assessed. Several ARB of highest priority for public health, such as carbapenem or extended-spectrum cephalosporin and/or fluoroquinolone-resistant Enterobacterales (including Salmonella enterica), fluoroquinolone-resistant Campylobacter spp., methicillin-resistant Staphylococcus aureus and glycopeptide-resistant Enterococcus faecium and E. faecalis were identified. Among highest priority ARGs blaCTX-M, blaVIM, blaNDM, blaOXA-48- like, blaOXA-23, mcr, armA, vanA, cfr and optrA were reported. These highest priority bacteria and genes were identified in different sources, at primary and post-harvest level, particularly faeces/manure, soil and water.
  • Commercial Vaccines Do Not Confer Protection Against Two Genetic Strains of 2 Piscirickettsia Salmonis, LF-89-Like and EM-90-Like, in Atlantic Salmon

    Commercial Vaccines Do Not Confer Protection Against Two Genetic Strains of 2 Piscirickettsia Salmonis, LF-89-Like and EM-90-Like, in Atlantic Salmon

    bioRxiv preprint doi: https://doi.org/10.1101/2021.01.07.424493; this version posted January 8, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 1 Commercial vaccines do not confer protection against two genetic strains of 2 Piscirickettsia salmonis, LF-89-like and EM-90-like, in Atlantic salmon. 3 Carolina Figueroa1, Débora Torrealba1, Byron Morales-Lange2, Luis Mercado2, Brian Dixon3, 4 Pablo Conejeros4, Gabriela Silva5, Carlos Soto5, José A. Gallardo1* 5 1Laboratorio de Genética y Genómica Aplicada, Escuela de Ciencias del Mar, Pontificia Universidad 6 Católica de Valparaíso, Valparaíso, Chile 7 2Grupo de Marcadores Inmunológicos en Organismos Acuáticos, Instituto de Biología, Pontificia 8 Universidad Católica de Valparaíso, Valparaíso, Chile 9 3Centro de Investigación y Gestión de Recursos Naturales (CIGREN), Instituto de Biología, Facultad 10 de Ciencias, Universidad de Valparaíso, Valparaíso, Chile 11 4Department of Biology, Faculty of Science, University of Waterloo, Waterloo, Ontario, Canada 12 5Salmones Camanchaca, Diego Portales 2000, Puerto Montt, Chile 13 * Correspondence: 14 José A. Gallardo 15 [email protected] 16 Keywords: pentavalent vaccine, live attenuated vaccine, Piscirickettsiosis, Salmo salar, 17 cohabitation, sea lice, vaccine efficacy. 18 Abstract 19 In Atlantic salmon, vaccines have failed to control and prevent Piscirickettsiosis, for reasons that 20 remain elusive. In this study, we report the efficacy of a commercial vaccine developed with the 21 Piscirickettsia salmonis isolate AL100005 against other two isolates which are considered highly and 22 ubiquitously prevalent in Chile: LF-89-like and EM-90-like.
  • PADLS User Guide

    PADLS User Guide

    PADLS User Guide Updated - 01/01/2017 [Type text] [Type text] Table of Contents Message from the Secretary .......................................................................................................................................................................... 3 Foreword ...................................................................................................................................................................................................... 4 Animal Health and Diagnostic Commission ..................................................................................................................................................... 5 PA Dept of Agriculture ................................................................................................................................................................................... 6 General information ...................................................................................................................................................................................... 8 Submission information ............................................................................................................................................................................... 13 Results and reports ...................................................................................................................................................................................... 20 Fees and Billing...........................................................................................................................................................................................
  • The Impact of Co-Infections on Fish: a Review

    The Impact of Co-Infections on Fish: a Review

    Kotob et al. Vet Res (2016) 47:98 DOI 10.1186/s13567-016-0383-4 REVIEW Open Access The impact of co‑infections on fish: a review Mohamed H. Kotob1,2, Simon Menanteau‑Ledouble1, Gokhlesh Kumar1, Mahmoud Abdelzaher2 and Mansour El‑Matbouli1* Abstract Co-infections are very common in nature and occur when hosts are infected by two or more different pathogens either by simultaneous or secondary infections so that two or more infectious agents are active together in the same host. Co-infections have a fundamental effect and can alter the course and the severity of different fish diseases. How‑ ever, co-infection effect has still received limited scrutiny in aquatic animals like fish and available data on this subject is still scarce. The susceptibility of fish to different pathogens could be changed during mixed infections causing the appearance of sudden fish outbreaks. In this review, we focus on the synergistic and antagonistic interactions occur‑ ring during co-infections by homologous or heterologous pathogens. We present a concise summary about the pre‑ sent knowledge regarding co-infections in fish. More research is needed to better understand the immune response of fish during mixed infections as these could have an important impact on the development of new strategies for disease control programs and vaccination in fish. Table of contents 1 Introduction 1 Introduction The subject of co-infections of aquatic animals by differ- 2 Co‑infections with homologous pathogens ent pathogens has received little attention even though such infections are common in nature. Co-infections are 2.1 Bacterial co‑infections defined by infection of the host by two or more geneti- 2.2 Viral co‑infections cally different pathogens where each pathogen has patho- 2.3 Parasitic co‑infections genic effects and causes harm to the host in coincidence 3 Co‑infections with heterologous pathogens with other pathogens [1, 2].