1
|
Knoben W, Graf S, Borutta F, Tegegne Z, Ningler M, Blom A, Dam H, Evers K, Schonenberg R, Schütz-Trilling A, Veerbeek J, Arnet R, Fretz M, Revol V, Valentin T, Bridges CR, Schulz SK, van Kerkhof J, Leenstra A, Orujov F, van Middendorp H. An Integrated Photonic Biosensing Platform for Pathogen Detection in Aquaculture. SENSORS (BASEL, SWITZERLAND) 2024; 24:5241. [PMID: 39204936 PMCID: PMC11358904 DOI: 10.3390/s24165241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2024] [Revised: 07/20/2024] [Accepted: 07/24/2024] [Indexed: 09/04/2024]
Abstract
Aquaculture is expected to play a vital role in solving the challenge of sustainably providing the growing world population with healthy and nutritious food. Pathogen outbreaks are a major risk for the sector, so early detection and a timely response are crucial. This can be enabled by monitoring the pathogen levels in aquaculture facilities. This paper describes a photonic biosensing platform based on silicon nitride waveguide technology with integrated active components, which could be used for such applications. Compared to the state of the art, the current system presents improvements in terms of miniaturization of the Photonic Integrated Circuit (PIC) and the development of wafer-level processes for hybrid integration of active components and for material-selective chemical and biological surface modification. Furthermore, scalable processes for integrating the PIC in a microfluidic cartridge were developed, as well as a prototype desktop readout instrument. Three bacterial aquaculture pathogens (Aeromonas salmonicida, Vagococcus salmoninarum, and Yersinia ruckeri) were selected for assay development. DNA biomarkers were identified, corresponding primer-probe sets designed, and qPCR assays developed. The biomarker for Aeromonas was also detected using the hybrid PIC platform. This is the first successful demonstration of biosensing on the hybrid PIC platform.
Collapse
Affiliation(s)
- Wout Knoben
- Surfix Diagnostics, Agro Business Park 2, 6708 PW Wageningen, The Netherlands (R.S.)
| | - Siegfried Graf
- CSEM, Untere Gründlistrasse 1, 6055 Alpnach, Switzerland
| | - Florian Borutta
- TunaTech GmbH, Merowingerplatz 1A, 40225 Düsseldorf, Germany; (F.B.)
| | - Zerihun Tegegne
- PHIX Photonics Assembly, Hengelosestraat 525, 7521 AG Enschede, The Netherlands; (Z.T.)
| | - Michael Ningler
- LRE Medical GmbH, Georg-Brauchle-Ring 89, 80992 München, Germany;
| | - Arthur Blom
- Surfix Diagnostics, Agro Business Park 2, 6708 PW Wageningen, The Netherlands (R.S.)
| | - Henk Dam
- Surfix Diagnostics, Agro Business Park 2, 6708 PW Wageningen, The Netherlands (R.S.)
| | - Kevin Evers
- Surfix Diagnostics, Agro Business Park 2, 6708 PW Wageningen, The Netherlands (R.S.)
| | - Rens Schonenberg
- Surfix Diagnostics, Agro Business Park 2, 6708 PW Wageningen, The Netherlands (R.S.)
| | - Anke Schütz-Trilling
- Surfix Diagnostics, Agro Business Park 2, 6708 PW Wageningen, The Netherlands (R.S.)
| | - Janneke Veerbeek
- Surfix Diagnostics, Agro Business Park 2, 6708 PW Wageningen, The Netherlands (R.S.)
| | - Roman Arnet
- CSEM, Untere Gründlistrasse 1, 6055 Alpnach, Switzerland
| | - Mark Fretz
- CSEM, Untere Gründlistrasse 1, 6055 Alpnach, Switzerland
| | - Vincent Revol
- CSEM, Untere Gründlistrasse 1, 6055 Alpnach, Switzerland
| | | | | | - Stephan K. Schulz
- TunaTech GmbH, Merowingerplatz 1A, 40225 Düsseldorf, Germany; (F.B.)
| | - Joost van Kerkhof
- PHIX Photonics Assembly, Hengelosestraat 525, 7521 AG Enschede, The Netherlands; (Z.T.)
| | - Anne Leenstra
- PHIX Photonics Assembly, Hengelosestraat 525, 7521 AG Enschede, The Netherlands; (Z.T.)
| | - Farid Orujov
- PHIX Photonics Assembly, Hengelosestraat 525, 7521 AG Enschede, The Netherlands; (Z.T.)
| | - Henk van Middendorp
- Surfix Diagnostics, Agro Business Park 2, 6708 PW Wageningen, The Netherlands (R.S.)
| |
Collapse
|
2
|
Sun XN, Wang Q, Wang YF, Tao Y, Zheng CL, Wang MH, Che MY, Cui ZH, Li XL, Zhang Q, Xu MX, Wang S, Nie P, Sun YL. Isolation and identification of vapA-absent Aeromonas salmonicida in diseased snakehead Channa argus in China. Int Microbiol 2024; 27:1137-1150. [PMID: 38062211 DOI: 10.1007/s10123-023-00455-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 11/10/2023] [Accepted: 11/13/2023] [Indexed: 08/06/2024]
Abstract
Aeromonas salmonicida is the typical pathogen causing furunculosis, reported widely in salmonids. Because of multiple serotypes, the control of A. salmonicida-caused disease has increasingly received much attention. Recently, A. salmonicida infection was reported in non-salmonid fish species. Here, a pathogenic A. salmonicida, named as As-s, was isolated from cultured snakehead (Channa argus) in a local fish farm in Shandong, China. As-s displayed clear hemolysis, amylase, and positive catalase activities, and grew at a wide range of temperatures (10-37 °C) and pH values (5.5-8.5). As-s was highly sensitive to cefuroxime sodium, ceftriaxone, ceftazidime, piperacillin, and cefoperazone and also apparently sensitive to chloramphenicol, erythromycin, and 25% cinnamaldehyde. The Virulence array protein gene cloning' results suggested that As-s has this gene compared with the other two vapA-containing strains, despite a close relationship of these strains via phylogenetic analysis. Severe ulcers on skin, muscle, and abnormal liver, and hemorrhage in pectoral/ventral fins and anal region were observed, and exophthalmos were also noticed in infected juvenile snakehead, as well as necrosis and infiltration of blood cells emerged in the internal organs using pathological section. In addition, As-s caused high mortality in snakehead, consistently with its immune gene response. This study reports the first isolation of vapA-absent A. salmonicida in snakehead.
Collapse
Affiliation(s)
- Xin Na Sun
- School of Marine Science and Engineering, Qingdao Agricultural University, 266237, Qingdao, Shandong, China
| | - Qing Wang
- School of Marine Science and Engineering, Qingdao Agricultural University, 266237, Qingdao, Shandong, China
| | - Ying Fei Wang
- School of Marine Science and Engineering, Qingdao Agricultural University, 266237, Qingdao, Shandong, China
| | - Ye Tao
- School of Marine Science and Engineering, Qingdao Agricultural University, 266237, Qingdao, Shandong, China
| | - Chao Li Zheng
- School of Marine Science and Engineering, Qingdao Agricultural University, 266237, Qingdao, Shandong, China
| | - Ming Hao Wang
- School of Marine Science and Engineering, Qingdao Agricultural University, 266237, Qingdao, Shandong, China
| | - Ming Yue Che
- School of Marine Science and Engineering, Qingdao Agricultural University, 266237, Qingdao, Shandong, China
| | - Zhen Hao Cui
- School of Marine Sciences, Ningbo University, 315832, Ningbo, Zhejiang, China
| | - Xin Long Li
- School of Marine Science and Engineering, Qingdao Agricultural University, 266237, Qingdao, Shandong, China
| | - Qian Zhang
- School of Marine Science and Engineering, Qingdao Agricultural University, 266237, Qingdao, Shandong, China
| | - Meng Xi Xu
- School of Marine Science and Engineering, Qingdao Agricultural University, 266237, Qingdao, Shandong, China
| | - Su Wang
- School of Marine Science and Engineering, Qingdao Agricultural University, 266237, Qingdao, Shandong, China
| | - Pin Nie
- School of Marine Science and Engineering, Qingdao Agricultural University, 266237, Qingdao, Shandong, China
| | - Yan Ling Sun
- School of Marine Science and Engineering, Qingdao Agricultural University, 266237, Qingdao, Shandong, China.
| |
Collapse
|
3
|
Smith P, Buba E, Desbois AP, Adams A, Verner-Jeffreys D, Joseph A, Light E, Le Devendec L, Jouy E, Larvor E, Boitard PM, Jamin M, Keck N, Le Breton A, Thuillier B, Ravaille C, Morin T, Baron S. Setting epidemiological cut-off values relevant to MIC and disc diffusion data for Aeromonas salmonicida generated by a standard method. DISEASES OF AQUATIC ORGANISMS 2024; 159:29-35. [PMID: 39087617 DOI: 10.3354/dao03798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/02/2024]
Abstract
The Clinical and Laboratory Standards Institute has published epidemiological cut-off values for susceptibility data generated at 22°°C and read after 44-48 h for florfenicol, oxolinic acid and oxytetracycline against Aeromonas salmonicida. The cut-off values for the minimum inhibitory concentration (MIC) and disc diffusion were derived from data obtained by 1 laboratory and 2 laboratories respectively. The present work reports the generation of susceptibility data from additional laboratories and the calculation of provisional cut-off values from aggregations of these data with previously published data. With respect to MIC data, the provisional cut-off values, derived from aggregations of the data from 4 laboratories, were ≤4 µg ml-1 for florfenicol, ≤0.0625 µg ml-1 for oxolinic acid and ≤1 µg ml-1 for oxytetracycline. For disc diffusion data, the provisional cut-off values derived from aggregations of the data from 5 laboratories were ≥30 mm for florfenicol, ≥32 mm for oxolinic acid and ≥25 mm for oxytetracycline. In addition, a cut-off value of ≥29 mm for ampicillin was derived from the aggregation of data from 4 laboratories.
Collapse
Affiliation(s)
- Peter Smith
- School of Natural Science, University of Galway, Galway H91 TK33, Ireland
| | - Elizabeth Buba
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling FK9 4LA, UK
- Veterinary Medicines Directorate (VMD), Woodham Lane, New Haw, Surrey KT15 3LS, UK
| | - Andrew P Desbois
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling FK9 4LA, UK
| | - Alexandra Adams
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling FK9 4LA, UK
| | - David Verner-Jeffreys
- Centre for Environment, Fisheries and Aquaculture Science, Weymouth DT4 8UB, UK
- UK FAO Reference Centre for AMR, Weymouth DT4 8UB, UK
| | - Andrew Joseph
- Centre for Environment, Fisheries and Aquaculture Science, Weymouth DT4 8UB, UK
- UK FAO Reference Centre for AMR, Weymouth DT4 8UB, UK
| | - Edel Light
- Veterinary Medicines Directorate (VMD), Woodham Lane, New Haw, Surrey KT15 3LS, UK
| | - Laëtitia Le Devendec
- Anses, Ploufragan-Plouzané-Niort Laboratory, Mycoplasmology-Bacteriology-Antibioresistance Unit, 22440 Ploufragan, France
| | - Eric Jouy
- Anses, Ploufragan-Plouzané-Niort Laboratory, Mycoplasmology-Bacteriology-Antibioresistance Unit, 22440 Ploufragan, France
| | - Emeline Larvor
- Anses, Ploufragan-Plouzané-Niort Laboratory, Mycoplasmology-Bacteriology-Antibioresistance Unit, 22440 Ploufragan, France
| | | | | | - Nicolas Keck
- Laboratoire Départemental Vétérinaire de l'Hérault, 34000 Montpellier, France
| | | | - Benoit Thuillier
- Labocéa, Microbiologie vétérinaire, site de Quimper, 29000 Quimper, France
| | | | - Thierry Morin
- Anses, Ploufragan-Plouzané-Niort Laboratory, Fish Virology, Immunology and Ecotoxicology Unit (VIMEP), 29280 Plouzané, France
| | - Sandrine Baron
- Anses, Ploufragan-Plouzané-Niort Laboratory, Mycoplasmology-Bacteriology-Antibioresistance Unit, 22440 Ploufragan, France
| |
Collapse
|
4
|
Chakraborty S, Gnanagobal H, Hossain A, Cao T, Vasquez I, Boyce D, Santander J. Inactivated Aeromonas salmonicida impairs adaptive immunity in lumpfish (Cyclopterus lumpus). JOURNAL OF FISH DISEASES 2024; 47:e13944. [PMID: 38523320 DOI: 10.1111/jfd.13944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 02/25/2024] [Accepted: 03/01/2024] [Indexed: 03/26/2024]
Abstract
Aeromonas salmonicida, a widely distributed aquatic pathogen causing furunculosis in fish, exhibits varied virulence, posing challenges in infectious disease and immunity studies, notably in vaccine efficacy assessment. Lumpfish (Cyclopterus lumpus) has become a valuable model for marine pathogenesis studies. This study evaluated several antigen preparations against A. salmonicida J223, a hypervirulent strain of teleost fish, including lumpfish. The potential immune protective effect of A. salmonicida bacterins in the presence and absence of the A-layer and extracellular products was tested in lumpfish. Also, we evaluated the impact of A. salmonicida outer membrane proteins (OMPs) and iron-regulated outer membrane proteins (IROMPs) on lumpfish immunity. The immunized lumpfish were intraperitoneally (i.p.) challenged with 104 A. salmonicida cells/dose at 8 weeks-post immunization (wpi). Immunized and non-immunized fish died within 2 weeks post-challenge. Our analyses showed that immunization with A. salmonicida J223 bacterins and antigen preparations did not increase IgM titres. In addition, adaptive immunity biomarker genes (e.g., igm, mhc-ii and cd4) were down-regulated. These findings suggest that A. salmonicida J223 antigen preparations hinder lumpfish immunity. Notably, many fish vaccines are bacterin-based, often lacking efficacy evaluation. This study offers crucial insights for finfish vaccine approval and regulations.
Collapse
Affiliation(s)
- Setu Chakraborty
- Marine Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Hajarooba Gnanagobal
- Marine Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Ahmed Hossain
- Marine Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Trung Cao
- Marine Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Ignacio Vasquez
- Marine Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Danny Boyce
- Department of Ocean Sciences, Dr. Joe Brown Aquatic Research Building, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Javier Santander
- Marine Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| |
Collapse
|
5
|
Bakiyev S, Smekenov I, Zharkova I, Kobegenova S, Sergaliyev N, Absatirov G, Bissenbaev A. Characterization of atypical pathogenic Aeromonas salmonicida isolated from a diseased Siberian sturgeon ( Acipenser baerii). Heliyon 2023; 9:e17775. [PMID: 37483743 PMCID: PMC10359828 DOI: 10.1016/j.heliyon.2023.e17775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 06/12/2023] [Accepted: 06/28/2023] [Indexed: 07/25/2023] Open
Abstract
Acipenser baerii (Siberian sturgeon) is native to Kazakhstan and is currently endangered and is listed within the first class of protected animals. Sturgeon aquaculture is becoming an important tool for the recovery of this endangered species. Nonetheless, diseases involving typical symptoms of skin ulceration and systemic bacterial hemorrhagic septicemia have occurred in cultured A. baerii on a fish farm located in Western Kazakhstan. In this study, an infectious strain of bacteria isolated from an ulcer of diseased A. baerii was identified as Aeromonas salmonicida (strain AB001). This identification involved analyses of 16S rRNA, gyrB, rpoD, and flaA genes' sequences. Even though strain AB001 belongs to A. salmonicida, it exhibited noticeable mobility and growth at temperatures of ≥37 °C. Profiling of virulence genes uncovered the presence of seven such genes related to pathogenicity. Antibiotic sensitivity testing showed that the strain is sensitive to aminoglycosides, amphenicols, nitrofurans, quinolones, and tetracyclines. Half-lethal doses (LD50) of strain AB001 for Oreochromis mossambicus and A. baerii were determined: respectively 1.7 × 108 and 7.2 × 107 colony-forming units per mL. The experimentally induced infection revealed that strain AB001 causes considerable histological lesions in O. mossambicus, including tissue degeneration, necrosis, and hemorrhages of varied severity.
Collapse
Affiliation(s)
- Serik Bakiyev
- Department of Molecular Biology and Genetics, Faculty of Biology and Biotechnology, al-Farabi Kazakh National University, Almaty 050040, Kazakhstan
- Scientific Research Institute of Biology and Biotechnology Problems, al-Farabi Kazakh National University, Almaty 050040, Kazakhstan
| | - Izat Smekenov
- Department of Molecular Biology and Genetics, Faculty of Biology and Biotechnology, al-Farabi Kazakh National University, Almaty 050040, Kazakhstan
- Scientific Research Institute of Biology and Biotechnology Problems, al-Farabi Kazakh National University, Almaty 050040, Kazakhstan
| | - Irina Zharkova
- Department of Biodiversity and Bioresources, Faculty of Biology and Biotechnology, al-Farabi Kazakh National University, Almaty 050040, Kazakhstan
| | - Saidina Kobegenova
- Department of Biodiversity and Bioresources, Faculty of Biology and Biotechnology, al-Farabi Kazakh National University, Almaty 050040, Kazakhstan
| | - Nurlan Sergaliyev
- Makhambet Utemisov West Kazakhstan University, Uralsk 090000, Kazakhstan
| | - Gaisa Absatirov
- West Kazakhstan Innovation and Technological University, Uralsk 090000, Kazakhstan
| | - Amangeldy Bissenbaev
- Department of Molecular Biology and Genetics, Faculty of Biology and Biotechnology, al-Farabi Kazakh National University, Almaty 050040, Kazakhstan
- Scientific Research Institute of Biology and Biotechnology Problems, al-Farabi Kazakh National University, Almaty 050040, Kazakhstan
| |
Collapse
|
6
|
Long M, Fan H, Gan Z, Jiang Z, Tang S, Xia H, Lu Y. Comparative genomic analysis provides insights into taxonomy and temperature adaption of Aeromonas salmonicida. JOURNAL OF FISH DISEASES 2023; 46:545-561. [PMID: 36861816 DOI: 10.1111/jfd.13767] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 02/06/2023] [Accepted: 02/07/2023] [Indexed: 06/18/2023]
Abstract
Aeromonas salmonicida has long been known as psychrophiles since it is mainly isolated from cold water fish, and recent reports have revealed the existence of mesophilic strains isolated from warm sources. However, the genetic differences between mesophilic and psychrophilic strains remain unclear due to few complete genomes of mesophilic strain are available. In this study, six A. salmonicida (2 mesophilic and 4 psychrophilic) were genome-sequenced, and comparative analyses of 25 A. salmonicida complete genomes were conducted. The ANI values and phylogenetic analysis revealed that 25 strains formed three independent clades, which were referred as typical psychrophilic, atypical psychrophilic and mesophilic groups. Comparative genomic analysis showed that two chromosomal gene clusters, related to lateral flagella and outer membrane proteins (A-layer and T2SS proteins), and insertion sequences (ISAs4, ISAs7 and ISAs29) were unique to the psychrophilic groups, while the complete MSH type IV pili were unique to the mesophilic group, all of which may be considered as lifestyle-related factors. The results of this study not only provide new insights into the classification, lifestyle adaption and pathogenic mechanism of different strains of A. salmonicida, but also contributes to the prevention and control of disease caused by psychrophilic and mesophilic A. salmonicida.
Collapse
Affiliation(s)
- Meng Long
- Guangdong Provincial Engineering Research Center for Aquatic Animal Health Assessment, and Shenzhen Public Service Platform for Evaluation of Marine Economic Animal Seedings, Shenzhen Institute of Guangdong Ocean University, Shenzhen, China
| | - Huimin Fan
- Guangdong Provincial Engineering Research Center for Aquatic Animal Health Assessment, and Shenzhen Public Service Platform for Evaluation of Marine Economic Animal Seedings, Shenzhen Institute of Guangdong Ocean University, Shenzhen, China
| | - Zhen Gan
- Guangdong Provincial Engineering Research Center for Aquatic Animal Health Assessment, and Shenzhen Public Service Platform for Evaluation of Marine Economic Animal Seedings, Shenzhen Institute of Guangdong Ocean University, Shenzhen, China
- Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, and Key Laboratory of Control for Disease of Aquatic Animals of Guangdong Higher Education Institute, College of Fishery, Guangdong Ocean University, Zhanjiang, China
| | - Zenghai Jiang
- College of Veterinary Medicine, Henan University of Animal Husbandry and Economy, Zhengzhou, China
| | - Shaoshuai Tang
- Guangdong Provincial Engineering Research Center for Aquatic Animal Health Assessment, and Shenzhen Public Service Platform for Evaluation of Marine Economic Animal Seedings, Shenzhen Institute of Guangdong Ocean University, Shenzhen, China
| | - Hongli Xia
- Guangdong Provincial Engineering Research Center for Aquatic Animal Health Assessment, and Shenzhen Public Service Platform for Evaluation of Marine Economic Animal Seedings, Shenzhen Institute of Guangdong Ocean University, Shenzhen, China
| | - Yishan Lu
- Guangdong Provincial Engineering Research Center for Aquatic Animal Health Assessment, and Shenzhen Public Service Platform for Evaluation of Marine Economic Animal Seedings, Shenzhen Institute of Guangdong Ocean University, Shenzhen, China
- Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, and Key Laboratory of Control for Disease of Aquatic Animals of Guangdong Higher Education Institute, College of Fishery, Guangdong Ocean University, Zhanjiang, China
| |
Collapse
|
7
|
Fu Q, Zhang H, Li Y, Zhang P, Gao C, Li J, Li X, Cao M, Li C. Transcriptomic characterization of Atlantic salmon (Salmo salar) head kidney following administration of Aeromonas salmonicida subsp. masoucida vaccine. FISH & SHELLFISH IMMUNOLOGY 2022; 126:150-163. [PMID: 35580798 DOI: 10.1016/j.fsi.2022.05.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Revised: 05/09/2022] [Accepted: 05/11/2022] [Indexed: 06/15/2023]
Abstract
Atlantic salmon is one of the most famous and economically important fish species globally. However, bacterial diseases constantly constrain salmon aquaculture. Thereinto, Aeromonas salmonicida subsp. masoucida (ASM), classified as atypical A. salmonicida, caused huge losses to salmonid industry in China. In this regard, we conducted transcriptome analysis in Atlantic salmon head kidney following the administration of ASM vaccination to reveal genes, their expression patterns, and pathways involved in immune responses. A total of 448.71 million clean reads were obtained, and 397.69 million reads were mapped onto the Atlantic salmon reference genome. In addition, 117, 1891, 741, 207, and 377 genes were significantly up-regulated, and 183, 1920, 695, 83, and 539 genes were significantly down-regulated post ASM vaccination at 12 h, 24 h, 1 m, 2 m, and 3 m, respectively. Furthermore, KEGG pathway analysis revealed that many differentially expressed genes (DEGs) following ASM vaccination were involved in cell adhesion molecules (H2-Aa-l and CD28-l),cytokine-cytokine receptor interaction (IL10, CXCL9, CXCL11, CXCR3, and CCL19), herpes simplex infection (IL1B, SOCS3-l, and C3-l), HTLV-I infection (Il1r2 and BCL2L1), influenza A (CXCL8 and Il12b), and PI3K-Akt signaling pathway (PIK3R3-l and Ddit4-l). Finally, the results of qRT-PCR showed a significant correlation with RNA-Seq results, suggesting the reliability of RNA-Seq for gene expression analysis. This study sets the foundation for further study on the vaccine protective mechanism in Atlantic salmon as well as other teleost species.
Collapse
Affiliation(s)
- Qiang Fu
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Hao Zhang
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Yuqing Li
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Pei Zhang
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Chengbin Gao
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Jie Li
- Key Laboratory of Maricultural Organism Disease Control, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
| | - Xingchun Li
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Min Cao
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Chao Li
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China.
| |
Collapse
|
8
|
Fu Q, Li Y, Zhang H, Cao M, Zhang L, Gao C, Cai X, Chen D, Yang Z, Li J, Yang N, Li C. Comparative Transcriptome Analysis of Spleen Reveals Potential Regulation of Genes and Immune Pathways Following Administration of Aeromonas salmonicida subsp. masoucida Vaccine in Atlantic Salmon (Salmo salar). MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2022; 24:97-115. [PMID: 35084599 PMCID: PMC8792528 DOI: 10.1007/s10126-021-10089-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 12/17/2021] [Indexed: 06/14/2023]
Abstract
Aeromonas salmonicida is a global fish pathogen. Aeromonas salmonicida subsp. masoucida (ASM) is classified as atypical A. salmonicida and caused huge losses to salmonid industry in China. Hence, it is of great significance to develop ASM vaccine and explore its protection mechanism in salmonids. In this regard, we conducted RNA-seq analysis with spleen tissue of Atlantic salmon after ASM vaccination to reveal genes, their expression patterns, and pathways involved in immune protections. In our results, a total of 441.63 million clean reads were obtained, and 389.37 million reads were mapped onto the Atlantic salmon reference genome. In addition, 1125, 2126, 1098, 820, and 1351 genes were significantly up-regulated, and 747, 2626, 818, 254, and 908 genes were significantly down-regulated post-ASM vaccination at 12 h, 24 h, 1 month, 2 months, and 3 months, respectively. Subsequent pathway analysis revealed that many differentially expressed genes (DEGs) following ASM vaccination were involved in cytokine-cytokine receptor interaction (TNFRSF11b, IL-17RA, CCR9, and CXCL11), HTLV-I infection (MR1 and HTLV-1), MAPK signaling pathway (MAPK, IL8, and TNF-α-1), PI3K-Akt signaling pathway (PIK3R3, THBS4, and COL2A1), and TNF signaling pathway (PTGS2, TNFRSF21-l, and CXCL10). Finally, the results of qRT-PCR showed a significant correlation with RNA-seq results, suggesting the reliability of RNA-seq for gene expression analysis. This study provided insights into regulation of gene expression and their involved pathways in Atlantic salmon spleen in responses to vaccine, and set the foundation for further study on the vaccine protective mechanism in Atlantic salmon as well as other teleost species.
Collapse
Affiliation(s)
- Qiang Fu
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Yuqing Li
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Hao Zhang
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Min Cao
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Lu Zhang
- Shandong Sinder Technology Co., Ltd, Zhucheng, 262200, China
| | - Chengbin Gao
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Xin Cai
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Defeng Chen
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Ziying Yang
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Jie Li
- Key Laboratory of Maricultural Organism Disease Control, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
| | - Ning Yang
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Chao Li
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China.
| |
Collapse
|
9
|
Papadopoulou A, Monaghan SJ, Bagwell N, Alves MT, Verner-Jeffreys D, Wallis T, Davie A, Adams A, Migaud H. Efficacy testing of an immersion vaccine against Aeromonas salmonicida and immunocompetence in ballan wrasse (Labrus bergylta, Ascanius). FISH & SHELLFISH IMMUNOLOGY 2022; 121:505-515. [PMID: 34673256 DOI: 10.1016/j.fsi.2021.09.044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 09/25/2021] [Accepted: 09/30/2021] [Indexed: 06/13/2023]
Abstract
The development of effective vaccines is a critical step towards the domestication of emerging fish species for aquaculture. However, traditional vaccine delivery through intraperitoneal (i.p.) injection requires fish to reach a minimum size and age and therefore cannot provide protection at early developmental stages when infection may occur. This study investigated the effectiveness of immersion vaccination with respect to immunocompetence in a cleaner fish species (ballan wrasse, Labrus bergylta, Ascanius) used in Atlantic salmon farming as an alternative means to control sea lice. The species is susceptible to atypical strains of Aeromonas salmonicida (aAs) at early life stages (<15 g), when i.p. vaccination is not applicable. While immersion vaccination is currently used in commercial hatcheries, the optimal fish size for vaccination, and efficacy of the vaccine delivered by this route has not yet been established. Importantly, efficacy depends on the capability of the species immune system to recognise antigens and process antigens to trigger and produce an adaptive immune response, (process known as immunocompetence). In this study, the efficacy of a polyvalent autogenous vaccine administered by immersion in juvenile ballan wrasse and the subsequent immune response induced was investigated after prime and booster vaccination regimes. In addition, temporal expression (0-150 days post hatch) of adaptive immune genes including major histocompatibility complex (MHC II CD74 molecule) and immunoglobulin M (IgM) was assessed using quantitative PCR (qPCR). Prime and/or boost vaccination by immersion of juvenile ballan wrasse (0.5 g and 1.5 g corresponding to 80 and 170 days post hatch (dph), respectively) did not provide significant protection against aAs vapA V after bath challenge under experimental conditions. Despite no evident protection >80 dph, MHC II and IgM transcripts were first reported at 35 and 75 dph, respectively, suggesting a window of immunocompetence. The results provide important new information on the onset of adaptive immunity in ballan wrasse and highlight that immersion vaccination in the species for protection against aAs should be performed at later developmental stages (>1.5 g) in the hatchery.
Collapse
Affiliation(s)
- Athina Papadopoulou
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, FK9 4LA, UK; Centre for Environment, Fisheries and Aquaculture Science, Barrack Road, the Nothe, Weymouth, Dorset, DT4 8UB, UK
| | - Sean J Monaghan
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, FK9 4LA, UK
| | - Nicola Bagwell
- Centre for Environment, Fisheries and Aquaculture Science, Barrack Road, the Nothe, Weymouth, Dorset, DT4 8UB, UK
| | - Mickael Teixeira Alves
- Centre for Environment, Fisheries and Aquaculture Science, Barrack Road, the Nothe, Weymouth, Dorset, DT4 8UB, UK
| | - David Verner-Jeffreys
- Centre for Environment, Fisheries and Aquaculture Science, Barrack Road, the Nothe, Weymouth, Dorset, DT4 8UB, UK
| | - Tim Wallis
- Ridgeway Biologicals Ltd. a Ceva Santé Animale Company, Units 1-3 Old Station Business Park, Compton, Berkshire, RG20 6NE, UK
| | - Andrew Davie
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, FK9 4LA, UK
| | - Alexandra Adams
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, FK9 4LA, UK
| | - Herve Migaud
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, FK9 4LA, UK.
| |
Collapse
|
10
|
To Be or Not to Be Mesophilic, That Is the Question for Aeromonas salmonicida. Microorganisms 2022; 10:microorganisms10020240. [PMID: 35208695 PMCID: PMC8879556 DOI: 10.3390/microorganisms10020240] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/15/2022] [Accepted: 01/20/2022] [Indexed: 02/05/2023] Open
Abstract
The bacterium Aeromonas salmonicida has long been known to be one of the most feared pathogens in fish farming. However, the more we discover about this bacterial species, the more we question whether it is really exclusively an aquatic pathogen. In recent years, it has become obvious that this bacterial species includes a myriad of strains with various lifestyle and ecological niches, including the well-known strict psychrophiles, the first bacteria known of the species, and the newly described mesophilic strains. The mesophiles are able to grow at low temperatures, but even better at temperatures of approximately 37 °C, which strict psychrophiles cannot do. In this perspective article, we address some aspects surrounding this dual lifestyle in A. salmonicida, including the impact of mobile genetic elements, and how future research around this bacterial species may focus on the psychrophilic/mesophilic dichotomy, which makes A. salmonicida an increasingly interesting and relevant model for the study of speciation.
Collapse
|
11
|
Comparative Genomics of Typical and Atypical Aeromonas salmonicida Complete Genomes Revealed New Insights into Pathogenesis Evolution. Microorganisms 2022; 10:microorganisms10010189. [PMID: 35056638 PMCID: PMC8780938 DOI: 10.3390/microorganisms10010189] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/05/2022] [Accepted: 01/12/2022] [Indexed: 02/04/2023] Open
Abstract
Aeromonas salmonicida is a global distributed Gram-negative teleost pathogen, affecting mainly salmonids in fresh and marine environments. A. salmonicida strains are classified as typical or atypical depending on their origin of isolation and phenotype. Five subspecies have been described, where A. salmonicida subsp. salmonicida is the only typical subspecies, and the subsp. achromogenes, masoucida, smithia, and pectinolytica are considered atypical. Genomic differences between A. salmonicida subsp. salmonicida isolates and their relationship with the current classification have not been explored. Here, we sequenced and compared the complete closed genomes of four virulent strains to elucidate their molecular diversity and pathogenic evolution using the more accurate genomic information so far. Phenotypes, biochemical, and enzymatic profiles were determined. PacBio and MiSeq sequencing platforms were utilized for genome sequencing. Comparative genomics showed that atypical strains belong to the subsp. salmonicida, with 99.55% ± 0.25% identity with each other, and are closely related to typical strains. The typical strain A. salmonicida J223 is closely related to typical strains, with 99.17% identity with the A. salmonicida A449. Genomic differences between atypical and typical strains are strictly related to insertion sequences (ISs) activity. The absence and presence of genes encoding for virulence factors, transcriptional regulators, and non-coding RNAs are the most significant differences between typical and atypical strains that affect their phenotypes. Plasmidome plays an important role in A. salmonicida virulence and genome plasticity. Here, we determined that typical strains harbor a larger number of plasmids and virulence-related genes that contribute to its acute virulence. In contrast, atypical strains harbor a single, large plasmid and a smaller number of virulence genes, reflected by their less acute virulence and chronic infection. The relationship between phenotype and A. salmonicida subspecies’ taxonomy is not evident. Comparative genomic analysis based on completed genomes revealed that the subspecies classification is more of a reflection of the ecological niche occupied by bacteria than their divergences at the genomic level except for their accessory genome.
Collapse
|
12
|
Kverme KO, Kallekleiv M, Larsen K, Rønneseth A, Wergeland HI, Samuelsen OB, Haugland GT. Antibacterial treatment of lumpfish (Cyclopterus lumpus) experimentally challenged with Vibrio anguillarum, atypical Aeromonas salmonicida and Pasteurella atlantica. JOURNAL OF FISH DISEASES 2022; 45:153-163. [PMID: 34719037 DOI: 10.1111/jfd.13545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 10/19/2021] [Accepted: 10/21/2021] [Indexed: 06/13/2023]
Abstract
Lumpfish is a novel farmed species used as cleaner fish for the removal of lice from farmed salmon. As often with new, farmed species, there are challenges with bacterial infections. The frequency of prescription of antibiotic agents to lumpfish is increasing, despite the lack of knowledge about appropriate doses, duration of treatment and application protocols for the various antibacterial agents. In the current study, we have tested the effect of medicated feed with florfenicol (FFC), oxolinic acid (OA) and flumequine (FLU) on lumpfish experimentally challenged with Vibrio anguillarum, atypical Aeromonas salmonicida and Pasteurella atlantica. We found that all three antibacterial agents efficiently treated lumpfish with vibriosis using 10 and 20 mg kg-1 day-1 of FFC, 25 mg kg-1 day-1 of OA and 25 mg kg-1 day-1 FLU, whereas only FFC (20 mg kg-1 day-1 ) had good effect on lumpfish with pasteurellosis. None of the antibacterial agents were efficient to treat lumpfish with atypical furunculosis. FFC 20 mg kg-1 day-1 showed promising results in the beginning of the experiment, but the mortality increased rapidly 14 days post-medication. Efficient treatment is important for the welfare of lumpfish and for reducing the risk of development of antibiotic-resistant bacteria. To our knowledge, this is the first study to establish protocols for antibacterial treatment of lumpfish.
Collapse
Affiliation(s)
- Karen O Kverme
- Department of Biological Sciences, University of Bergen, Bergen, Norway
| | | | - Kristina Larsen
- Department of Biological Sciences, University of Bergen, Bergen, Norway
| | - Anita Rønneseth
- Department of Biological Sciences, University of Bergen, Bergen, Norway
| | | | | | - Gyri T Haugland
- Department of Biological Sciences, University of Bergen, Bergen, Norway
| |
Collapse
|
13
|
Zhou S, Huang Q, Yu M, Li Y, Zheng X, Xiu Y. Rapid visual detection of Aeromonas salmonicida by loop-mediated isothermal amplification with hydroxynaphthol blue dye. JOURNAL OF FISH DISEASES 2021; 44:1993-2001. [PMID: 34411329 DOI: 10.1111/jfd.13513] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Revised: 07/26/2021] [Accepted: 07/28/2021] [Indexed: 06/13/2023]
Abstract
To make crucial prevention, reduce fish losses and minimize the economic damage of diseases on the fish farm owners, a rapid detection of fish pathogens is mandatory. In this study, a loop-mediated isothermal amplification assay combined with hydroxynaphthol blue dye (LAMP-HNB) was developed and used for the rapid detection of Aeromonas salmonicida that caused significant economic losses in fish farming. Firstly, a pair of outer and inner primers specific for conserved fragment of vapA gene in A. salmonicida were designed and synthesized. Secondly, by optimizing the reaction conditions including reaction temperature, time, Mg2+ concentration, dNTP concentration and primer ratio, a LAMP-HNB assay was successfully established for the detection of A. salmoncida. Thirdly, the assay showed good specificity with no false-positive and false-negative results, and good sensitivity with the detection limit of 3.077 × 10-6 ng/μl, which was 102 times more sensitive than the conventional PCR. Finally, the LAMP-HNB assay was validated by the fish samples inoculated with different concentrations of A. salmoncida. This is the first development of rapid visual detection of A. salmonicida based on LAMP-HNB assay, which has great application prospect and market for diagnostic testing, health certification and active surveillance programmers.
Collapse
Affiliation(s)
- Shun Zhou
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, China
| | - Qing Huang
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, China
| | - Mingming Yu
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, China
| | - Ying Li
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, China
| | - Xujia Zheng
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, China
| | - Yunji Xiu
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, China
| |
Collapse
|
14
|
Isolation of a Virulent Aeromonas salmonicida subsp. masoucida Bacteriophage and Its Application in Phage Therapy in Turbot ( Scophthalmus maximus). Appl Environ Microbiol 2021; 87:e0146821. [PMID: 34406829 DOI: 10.1128/aem.01468-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Aeromonas salmonicida is an aquatic pathogen that can infect a variety of fish. Phage therapy has been applied to treat bacterial infections. In this study, we obtained three A. salmonicida subsp. masoucida phage isolates from sewage, and one phage (vB_AsM_ZHF) exhibited the best antibacterial effect, based on in vitro kinetics experiments. Sequencing indicated that the vB_AsM_ZHF genome is 161,887 bp (41.24% C+G content) with 237 predicted open reading frames. No antibiotic resistance or virulence genes were detected in the complete genome, which is a requirement for phage therapy safety. Intraperitoneal injection of phage vB_AsM_ZHF into turbot at 8 × 104 PFU/fish rescued turbot from A. salmonicida subsp. masoucida injection and reduced the bacterial burden by 1 order of magnitude. Injection of vB_AsM_ZHF also decreased levels of inflammatory cell infiltration in muscle tissue, cytokines interleukin-1β (IL-1β), tumor necrosis factor alpha (TNF-α), and gamma interferon (IFN-γ) in serum and the expression of the inflammatory factors IL-1β, IL-6, IFN-γ, transforming growth factor β, TNF-α, and hepcidin in the liver, spleen, and head kidney of turbot. Phage vB_AsM_ZHF demonstrated antibacterial ability in vitro and in vivo and significantly reduced mortality in turbot challenged by A. salmonicida subsp. masoucida. This study revealed that phage vB_AsM_ZHF can effectively treat the infection caused by A. salmonicida subsp. masoucida in turbot. IMPORTANCE A. salmonicida is an aquatic pathogen that can infect different fish and causes economic loss to the global aquaculture industry. Clinical strains of A. salmonicida have developed multidrug resistance, and phage therapy is being evaluated for controlling bacterial infections. Phages are biological antibacterial agents and have the potential to be therapeutic agents against multidrug-resistant bacteria. In this study, three A. salmonicida subsp. masoucida phages were isolated from sewage, and their biological behaviors were characterized. The newly isolated phage vB_AsM_ZHF could inhibit A. salmonicida subsp. masoucida infection in vitro and in vivo, suggesting that it may be an alternative strategy to antibiotics for protecting fish against multidrug-resistant A. salmonicida subsp. masoucida in the aquaculture industry.
Collapse
|
15
|
Corrigendum. JOURNAL OF FISH DISEASES 2021. [PMID: 34114210 DOI: 10.1111/jfd.13399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
|
16
|
Papadopoulou A, Garvey K, Hill T, Ramirez-Paredes JG, Monaghan SJ, Baily JL, Davie A, Katsiadaki I, Verner-Jeffreys D, Wallis T, Migaud H, Adams A. Novel atypical Aeromonas salmonicida bath challenge model for juvenile ballan wrasse (Labrus bergylta, Ascanius). JOURNAL OF FISH DISEASES 2021; 44:823-835. [PMID: 33277726 DOI: 10.1111/jfd.13312] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 11/08/2020] [Accepted: 11/09/2020] [Indexed: 06/12/2023]
Abstract
Atypical Aeromonas salmonicida (aAs) is currently one of the most routinely recovered bacterial pathogens isolated during disease outbreaks in farmed cleaner fish, ballan wrasse (Labrus bergylta, Ascanius). Vibrionaceae family bacteria have also been isolated from ballan wrasse in Scotland. This study determined the infectivity, pathogenicity and virulence of aAs and Vibrionaceae isolates in juvenile farmed ballan wrasse (n = 50; approx. 2 g) using a bath challenge, and fish were monitored for a period of 16 days. Atypical As caused significant mortalities in contrast to Vibrionaceae isolates. Notably, differential virulence was observed between two aAs vapA type V strains at similar challenge doses. Diseased fish exhibited a systemic infection where aAs was detected in all analysed tissues (liver, spleen and kidney) by PCR and qPCR. Macroscopically, moribund and survivor fish exhibited hepatomegaly and splenomegaly. In moribund and surviving fish, histopathology showed granulomatous hepatitis with eosinophilic granular cells surrounding bacterial colonies and endocarditis along with splenic histiocytosis. This is the first report of a successful aAs bath challenge model for juvenile ballan wrasse which provides an important tool for future studies on vaccine efficacy and immunocompetence.
Collapse
Affiliation(s)
- Athina Papadopoulou
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, UK
| | - Kathryn Garvey
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, UK
| | - Tom Hill
- Centre for Environment, Fisheries and Aquaculture Science, Weymouth, UK
| | - Jose G Ramirez-Paredes
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, UK
- Ridgeway Biologicals Ltd. a Ceva Santé Animale company, Compton, UK
| | - Sean J Monaghan
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, UK
| | - Johanna L Baily
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, UK
| | - Andrew Davie
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, UK
| | - Ioanna Katsiadaki
- Centre for Environment, Fisheries and Aquaculture Science, Weymouth, UK
| | | | - Timothy Wallis
- Ridgeway Biologicals Ltd. a Ceva Santé Animale company, Compton, UK
| | - Herve Migaud
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, UK
| | - Alexandra Adams
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, UK
| |
Collapse
|
17
|
Papadopoulou A, Davie A, Monaghan SJ, Migaud H, Adams A. Development of diagnostic assays for differentiation of atypical Aeromonas salmonicida vapA type V and type VI in ballan wrasse (Labrus bergylta, Ascanius). JOURNAL OF FISH DISEASES 2021; 44:711-719. [PMID: 33493378 DOI: 10.1111/jfd.13334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 12/29/2020] [Accepted: 12/30/2020] [Indexed: 06/12/2023]
Abstract
Aeromonas salmonicida (As) is a highly heterogeneous bacterial species, and strains' host specificity has been reported. Ballan wrasse (Labrus bergylta Ascanius, 1767) is susceptible to atypical As (aAs) vapA type V and type VI in Scotland and Norway. Identification of the bacterium is achieved by culture and molecular techniques; however, the available methods used to distinguish the As types are costly and time-consuming. This paper describes the development of a PCR and a restriction enzyme assay for the detection of aAs vapA type V and type VI in ballan wrasse, respectively. Type V-specific primers were designed on conserved regions of the vapA gene, and the restriction enzyme assay was performed on the PCR products of the hypervariable region of vapA gene for the detection of type VI isolates. Amplification product was produced for type V (254 bp) and restriction bands (368 and 254 bp) for type VI isolates only. In addition, the assays detected type V and type VI isolates in spiked water samples and type V in diagnostic tissue samples. The assays are fast, specific and cost-effective and can be used as specific diagnostic tools for cleaner fish, to detect infectious divergence strains, and to manage and mitigate aAs disease outbreaks through vaccine development.
Collapse
Affiliation(s)
- Athina Papadopoulou
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, UK
| | - Andrew Davie
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, UK
| | - Sean J Monaghan
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, UK
| | - Herve Migaud
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, UK
| | - Alexandra Adams
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, UK
| |
Collapse
|
18
|
Characterization of bacteriophage T7-Ah reveals its lytic activity against a subset of both mesophilic and psychrophilic Aeromonas salmonicida strains. Arch Virol 2021; 166:521-533. [PMID: 33394168 DOI: 10.1007/s00705-020-04923-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 11/04/2020] [Indexed: 12/16/2022]
Abstract
Aeromonas salmonicida strains cause problematic bacterial infections in the aquaculture industry worldwide. The genus Aeromonas includes both mesophilic and psychrophilic species. Bacteriophages that infect Aeromonas spp. strains are usually specific for mesophilic or psychrophilic species; only a few bacteriophages can infect both types of strains. In this study, we characterized the podophage T7-Ah, which was initially found to infect the Aeromonas salmonicida HER1209 strain. The burst size of T7-Ah against its original host is 72 new virions per infected cell, and its burst time is 30 minutes. It has been found that this phage can lyse both mesophilic and psychrophilic A. salmonicida strains, as well as one strain of Escherichia coli. Its genome comprises 40,153 bp of DNA and does not contain any recognizable toxin or antibiotic resistance genes. The adsorption rate of the phage on highly sensitive bacterial strains was variable and could not be related to the presence or absence of a functional A-layer on the surface of the bacterial strains. The lipopolysaccharide migration patterns of both resistant and sensitive bacterial strains were also studied and compared to investigate the nature of the potential receptor of this phage on the bacterial surface. This study sheds light on the surprising diversity of lifestyles of the bacterial strains sensitive to phage T7-Ah and opens the door to the potential use of this phage against A. salmonicida infections in aquaculture.
Collapse
|
19
|
Huang L, Qi W, Zuo Y, Alias SA, Xu W. The immune response of a warm water fish orange-spotted grouper (Epinephelus coioides) infected with a typical cold water bacterial pathogen Aeromonas salmonicida is AhR dependent. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2020; 113:103779. [PMID: 32735958 DOI: 10.1016/j.dci.2020.103779] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Revised: 06/21/2020] [Accepted: 06/21/2020] [Indexed: 06/11/2023]
Abstract
The present study reported the first pathogenic Aeromonas salmonicida (SRW-OG1) isolated from the warm water fish orange-spotted grouper (Epinephelus coioides), and investigated the function of Aryl hydrocarbon receptor (AhR), a ligand-dependent transcriptional factor which has been recently found to be closely associated with immune response in mammals and E. coioides. Our results showed that AhR was activated by an unknown ligand in the spleen, intestine and macrophages. Meanwhile, ahr1a and ahr1b were significantly increased in the spleen, intestine and macrophages, whereas ahr2 was only increased in the intestine, which indicated that the contribution of AhR2 to the immune response may be less than that of AhR1a and AhR1b. Some key genes involved in the macrophage inflammatory response, bacterial recognition, and intestinal immunity were significantly up-regulated in the SRW-OG1 infected E. coioides. Nevertheless, declining macrophage ROS production and down-regulation of related genes were also observed, suggesting that SRW-OG1 utilized its virulence mechanisms to prevent macrophage ROS production. Furthermore, AhR inhibitor 3', 4'-DMF and the silence of ahr1a or ahr1b significantly rescued the increased IL-1β and IL-8 induced by SRW-OG1 infection, which proved that the induction of IL-1β and IL-8 in E. coioides macrophages was mediated by AhR. However, BPI/LBP, ROS production and related genes were not affected by AhR. The survival rate and immune escape rate of SRW-OG1 in the ahr1a/ahr1b knocked-down and 3', 4'-DMF treated macrophages were significantly increased compared with those in wild type macrophages. Taken together, it was preliminarily confirmed that ahr1a and ahr1b played an important role in the immune response against A. salmonicida SRW-OG1.
Collapse
Affiliation(s)
- Lixing Huang
- Fisheries College, Fujian Engineering Research Center of Aquatic Breeding and Healthy Aquaculture, Jimei University, Xiamen, Fujian, PR China.
| | - Weilu Qi
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, Fujian, PR China
| | - Yanfei Zuo
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, Fujian, PR China
| | - Siti Aisyah Alias
- Institute of Ocean and Earth Science (IOES), C308, Institute of Postgraduate Studies Building, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Wei Xu
- Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361005, PR China.
| |
Collapse
|
20
|
Ramirez-Paredes JG, Verner-Jeffreys DW, Papadopoulou A, Monaghan SJ, Smith L, Haydon D, Wallis TS, Davie A, Adams A, Migaud H. A commercial autogenous injection vaccine protects ballan wrasse (Labrus bergylta, Ascanius) against Aeromonas salmonicida vapA type V. FISH & SHELLFISH IMMUNOLOGY 2020; 107:43-53. [PMID: 33011432 DOI: 10.1016/j.fsi.2020.09.040] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 09/22/2020] [Accepted: 09/28/2020] [Indexed: 06/11/2023]
Abstract
Atypical Aeromonas salmonicida (aAs) and Vibrionaceae related species are bacteria routinely recovered from diseased ballan wrasse used as cleaner fish in the Atlantic salmon farming industry. Autogenous (i.e. farm specific inactivated) multivalent vaccines formulated from these microorganisms are widely used to protect farmed wrasse despite limited experimental proof that they are primary pathogens. In this study, the components of a commercial multivalent injection vaccine containing four strains of Aeromonas salmonicida and one strain of Vibrio splendidus previously isolated from ballan wrasse in Scotland, were tested for infectivity, pathogenicity and virulence via intra peritoneal injection at pre-deployment size (25-50 g) and the efficacy of the vaccine for protection against aAs assessed. Injection with 3.5 × 109, 8 × 109 1.8 × 109 and 5 × 109 cfu/fish of Vibrio splendidus, V. ichthyoenteri, Aliivibrio logeii and A. salmonicida, respectively, did not cause significant mortalities, lesions or clinical signs after a period of 14 days. IP injection with both aAs and Photobacterium indicum successfully reproduced the clinical signs and internal lesions observed during natural outbreaks of the disease. Differences in virulence (LD50 at day 8-post infection of 3.6 × 106 cfu/fish and 1.6 × 107 cfu/fish) were observed for two aAs vapA type V isolates. In addition, the LD50 for Photobacterium indicum was 2.2 × 107 cfu/fish. The autogenous vaccine was highly protective against the two aAs vapA type V isolates after 700-degree days of immunisation. The RPSFINAL values for the first isolate were 95 and 91% at 1 × 106 cfu/fish and 1 × 107 cfu/fish, respectively, and 79% at 1 × 107 cfu/fish for the second isolate tested. In addition, significantly higher anti aAs seral antibodies (IgM), were detected by ELISA in vaccinated fish in contrast with control (mock vaccinated) fish. These results suggest wrasse can be effectively immunised and protected against aAs infection by injection with oil adjuvanted vaccines prepared with inactivated homologous isolates.
Collapse
Affiliation(s)
- J G Ramirez-Paredes
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, Scotland, FK9 4LA, UK; Ridgeway Biologicals Ltd. a Ceva Santé Animale Company, Units 1-3 Old Station Business Park, Compton, Berkshire, England, RG20 6NE, UK
| | - D W Verner-Jeffreys
- Centre for Environment, Fisheries and Aquaculture Science, Barrack Road - the Nothe, Weymouth, Dorset, England, DT4 8UB, UK
| | - A Papadopoulou
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, Scotland, FK9 4LA, UK
| | - S J Monaghan
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, Scotland, FK9 4LA, UK
| | - L Smith
- Centre for Environment, Fisheries and Aquaculture Science, Barrack Road - the Nothe, Weymouth, Dorset, England, DT4 8UB, UK
| | - D Haydon
- Ridgeway Biologicals Ltd. a Ceva Santé Animale Company, Units 1-3 Old Station Business Park, Compton, Berkshire, England, RG20 6NE, UK
| | - T S Wallis
- Ridgeway Biologicals Ltd. a Ceva Santé Animale Company, Units 1-3 Old Station Business Park, Compton, Berkshire, England, RG20 6NE, UK
| | - A Davie
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, Scotland, FK9 4LA, UK
| | - A Adams
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, Scotland, FK9 4LA, UK
| | - H Migaud
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, Scotland, FK9 4LA, UK.
| |
Collapse
|
21
|
Wang P, Li J, He TT, Li N, Mo ZL, Nie P, Xie HX. Pathogenic characterization of Aeromonas salmonicida subsp. masoucida turbot isolate from China. JOURNAL OF FISH DISEASES 2020; 43:1145-1154. [PMID: 32720397 DOI: 10.1111/jfd.13224] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 07/01/2020] [Accepted: 07/02/2020] [Indexed: 06/11/2023]
Abstract
Aeromonas salmonicida is a gram-negative bacterium that is the causative agent of furunculosis. An A. salmonicida strain was isolated from diseased turbot (Scophthalmus maximus) with the sign of furunculosis from North China. Based on vapA gene, the strain was further classified as A. salmonicida subsp. masoucida RZ6S-1. Culturing RZ6S-1 strain at high temperature (28°C) obtained the virulence attenuated strain RZ6S. Genome sequence comparison between the two strains revealed the loss of the type IV secretion system (T4SS) and type III secretion system (T3SS) from the native plasmid pAsmB-1 and pAsmC-1 of wild-type strain RZ6S-1, respectively. Further study demonstrated that the wild-type strain RZ6S-1, but not its derivative mutant RZ6S, can stimulate apoptosis. Elevated protein level of cleaved caspase-3 was detected from epithelioma papulosum cyprinid (EPC) cells infected with wild-type strain RZ6S-1 as compared with that infected with RZ6S strain. Meanwhile, the invasion of the mutant strain RZ6S was about 17-fold higher than the wild-type strain RZ6S-1, suggesting that some protein(s) from A. salmonicida subsp. masoucida RZ6S-1 suppress its invasion. The RZ6S mutant strain was attenuated, since its LD50 is over 10,000 times higher compared to the wild-type strain as revealed in the turbot infection model.
Collapse
Affiliation(s)
- Ping Wang
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, China
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Jie Li
- Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
| | - Tian Tian He
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Nan Li
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Zhao Lan Mo
- Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
| | - Pin Nie
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, China
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, China
| | - Hai Xia Xie
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| |
Collapse
|
22
|
Papadopoulou A, Wallis T, Ramirez-Paredes JG, Monaghan SJ, Davie A, Migaud H, Adams A. Atypical Aeromonas salmonicida vapA type V and Vibrio spp. are predominant bacteria recovered from ballan wrasse Labrus bergylta in Scotland. DISEASES OF AQUATIC ORGANISMS 2020; 140:47-54. [PMID: 32614330 DOI: 10.3354/dao03489] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Healthy and/or moribund farmed and wild ballan wrasse Labrus bergylta (>0.5 to 900 g) were sampled from hatcheries (n = 2) and Atlantic salmon Salmo salar cage sites (n = 8) in Scotland between February 2016 and October 2018. Less than half of the sampled individuals (n = 43; 32.3%) had been vaccinated (autogenous polyvalent vaccine; dip and/or injection) against atypical furunculosis (type V and VI), while 20 (15.0%) fish were not vaccinated, and the rest (70 individuals, 52.7%) were of unknown vaccination status. Swab samples from skin lesions, gill, liver, spleen and kidney were inoculated onto a variety of bacteriological agar plates, and bacteriology identification and sequencing analysis was performed on significant bacterial colonies. Atypical Aeromonas salmonicida (aAs) vapA type V was the predominant bacterial species (70/215 bacterial isolates, 32.5% of bacterial samples; 43/117 positive individual fish, 36.8%) isolated in this survey followed by Vibrio species, which were the most geographically prevalent bacteria. Photobacterium indicum/profundum was also isolated from L. bergylta for the first time during this study. The collection of these bacterial isolates provides useful information for disease management. Identifying the aAs isolates involved in disease in ballan wrasse could provide vital information for improving/updating existing autogenous vaccines.
Collapse
Affiliation(s)
- A Papadopoulou
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling FK9 4LA, UK
| | | | | | | | | | | | | |
Collapse
|
23
|
Gulla S, Bayliss S, Björnsdóttir B, Dalsgaard I, Haenen O, Jansson E, McCarthy U, Scholz F, Vercauteren M, Verner-Jeffreys D, Welch T, Wiklund T, Colquhoun DJ. Biogeography of the fish pathogen Aeromonas salmonicida inferred by vapA genotyping. FEMS Microbiol Lett 2020; 366:5449007. [PMID: 30977802 PMCID: PMC6502549 DOI: 10.1093/femsle/fnz074] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 04/10/2019] [Indexed: 11/14/2022] Open
Abstract
A recently described typing system based on sequence variation in the virulence array protein (vapA) gene, encoding the A-layer surface protein array, allows unambiguous subtyping of Aeromonas salmonicida. In the present study, we compile A-layer typing results from a total of 675 A. salmonicida isolates, recovered over a 59-year period from 50 different fish species in 26 countries. Nine novel A-layer types (15–23) are identified, several of which display a strong predilection towards certain fish hosts, including e.g. Cyprinidae and Pleuronectidae species. Moreover, we find indications that anthropogenic transport of live fish may have aided the near global dissemination of two cyprinid-associated A-layer types. Comparison of whole genome phylogeny and A-layer typing for a subset of strains further resulted in compatible tree topologies, indicating the utility of vapA as a phylogenetic as well as an epizootiological marker in A. salmonicida. A Microreact project (microreact.org/project/r1pcOAx9m) has been created, allowing public access to the vapA analyses and relevant metadata. In sum, the results generated provide valuable insights into the global population structure of A. salmonicida, particularly in relation to its piscine host spectrum and the geographic distribution of these hosts.
Collapse
Affiliation(s)
- Snorre Gulla
- Fish Health Research Group, Norwegian Veterinary Institute, Oslo, Norway
| | - Sion Bayliss
- The Milner Centre for Evolution, Department of Biology & Biotechnology, University of Bath, Bath, England
| | | | - Inger Dalsgaard
- National Institute of Aquatic Resources, Technical University of Denmark, Lyngby, Denmark
| | - Olga Haenen
- NRL for Fish Diseases, Wageningen Bioveterinary Research, Lelystad, the Netherlands
| | - Eva Jansson
- Department of Animal Health and Antimicrobial strategies, National Veterinary Institute (SVA), Uppsala, Sweden
| | - Una McCarthy
- Marine Scotland Science, Marine Laboratory, Aberdeen, Scotland
| | | | - Maaike Vercauteren
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | | | - Tim Welch
- National Center for Cool and Cold Water Aquaculture, Agricultural Research Service, US Department of Agriculture, Kearneysville, West Virginia, USA
| | - Tom Wiklund
- Laboratory of Aquatic Pathobiology, Environmental and Marine Biology, Åbo Akademi University, Turku, Finland
| | - Duncan J Colquhoun
- Fish Health Research Group, Norwegian Veterinary Institute, Oslo, Norway.,Department of Biological Sciences, University of Bergen, Bergen, Norway
| |
Collapse
|
24
|
Vercauteren M, De Swaef E, Declercq AM, Aerts J, Ampe B, Gulla S, Haesebrouck F, Devriese L, Decostere A, Chiers K. Pinpointing the role of Aeromonas salmonicida in the development of skin ulcerations in common dab (Limanda limanda). JOURNAL OF FISH DISEASES 2020; 43:347-357. [PMID: 31918449 DOI: 10.1111/jfd.13133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 12/12/2019] [Accepted: 12/13/2019] [Indexed: 06/10/2023]
Abstract
Aeromonas salmonicida was isolated from ulcerations in common dab (Limanda limanda). An experiment was performed to pinpoint its role in ulceration development, considering the importance of the skin barrier and the pigmented and non-pigmented sides. The skin of dab was treated in three zones, one where scales and epidermis were removed, one where mucus was discarded and one non-treated zone. Fish were tagged to allow individual identification and challenged with A. salmonicida. Mortality and severity of the developing lesions were recorded for 21 days post-inoculation. Starting 12 days post-inoculation, mortality occurred gradually in challenged fish; however, no direct cause could be established. Both control fish and challenged fish developed ulcerations containing A. salmonicida. Sequencing of vapA gene revealed that isolates retrieved from both groups were distinct, suggesting the presence of A. salmonicida prior to the trial. Most ulcerations developed in zones where skin was removed, suggesting that abrasion might be a predisposing factor in ulceration development. Ulcerations were also observed at the insertion site of the tag, where exposed muscle tissue might have favoured the development of ulcerations. In conclusion, A. salmonicida seems to be involved in the development of skin ulcerations in dab, although the exact pathogenesis needs to be elucidated.
Collapse
Affiliation(s)
- Maaike Vercauteren
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Evelien De Swaef
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Annelies Maria Declercq
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Johan Aerts
- Stress Physiology Research Group, Ghent University and Flanders Research Institute for Agricultural and Fisheries and Food (ILVO), Green Bridge Science Park, Ostend, Belgium
| | - Bart Ampe
- Animal Husbandry, Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), Melle, Belgium
| | - Snorre Gulla
- Fish Health Research Group, Norwegian Veterinary Institute, Oslo, Norway
| | - Freddy Haesebrouck
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Lisa Devriese
- Flanders Marine Institute (VLIZ), InnovOcean site, Ostend, Belgium
- Research Institute for Agriculture, Fisheries and Food (ILVO), Ostend, Belgium
| | - Annemie Decostere
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Koen Chiers
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| |
Collapse
|
25
|
Zehady AK, Fordham BG, Ogg JG. Integrated species-phenon trees: visualizing infraspecific diversity within lineages. Sci Rep 2019; 9:18968. [PMID: 31831804 PMCID: PMC6908663 DOI: 10.1038/s41598-019-55435-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 10/25/2019] [Indexed: 12/03/2022] Open
Abstract
The unprecedented detail with which contemporary molecular phylogenetics are visualizing infraspecific relationships within living species and species complexes cannot as yet be reliably extended into deep time. Yet paleontological systematics has routinely dealt in (mainly) morphotaxa envisaged in various ways to have been components of past species lineages. Bridging these perspectives can only enrich both. We present a visualization tool that digitally depicts infraspecific diversity within species through deep time. Our integrated species-phenon tree merges ancestor-descendant trees for fossil morphotaxa (phena) into reconstructed phylogenies of lineages (species) by expanding the latter into "species boxes" and placing the phenon trees inside. A key programming strategy to overcome the lack of a simple overall parent-child hierarchy in the integrated tree has been the progressive population of a species-phenon relationship map which then provides the graphical footprint for the overarching species boxes. Our initial case has been limited to planktonic foraminfera via Aze & others' important macroevolutionary dataset. The tool could potentially be appropriated for other organisms, to detail other kinds of infraspecific granularity within lineages, or more generally to visualize two nested but loosely coupled trees.
Collapse
Affiliation(s)
- Abdullah Khan Zehady
- Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, IN, USA
| | - Barry G Fordham
- Research School of Earth Sciences, Australian National University, Canberra, ACT, Australia.
| | - James G Ogg
- Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, IN, USA
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu, Sichuan, China
| |
Collapse
|
26
|
McMurtrie J, Verner-Jeffreys DW, Cochrane-Dyet T, White P, van Aerle R, Ryder D, Stone D, Green M, Feist SW, Cano I. Health assessment of the cleaner fish ballan wrasse Labrus bergylta from the British south-west coast. DISEASES OF AQUATIC ORGANISMS 2019; 136:133-146. [PMID: 31621646 DOI: 10.3354/dao03394] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Wild-caught ballan wrasse Labrus bergylta are translocated en masse from the British south-west coast to Scotland for use as cleaner fish to tackle Atlantic salmon Salmo salar sea lice infestations; however, very little is known about the background health status of this species. This is the first health assessment of wild ballan wrasse from the British south-west. Wild-caught ballan wrasse (n = 75) from coastal populations off Dorset and Cornwall were subjected to a full health screen for viral, bacterial and parasitic infections and associated pathology. A range of metazoan and protozoan parasites were observed in histological sections, including copepods (sea lice Caligus centrodonti), nematodes, cestodes, digenean metacercariae, Cryptocaryon-like ciliates and an intestinal coccidian (Eimeria sp.) observed in 26.6% of the samples. The mycoplasma Acholeplasma laidlawii was associated with cytopathic effect in cell culture inoculated with tissue homogenates. The opportunistic pathogen Photobacterium damselae damselae was isolated from a single fish with a systemic infection. The isolate was confirmed to possess the virulence factors hlyAch and plpV, previously associated with cell toxicity and pathogenicity to fish. There are no immediate concerns for the continued mass translation of ballan wrasse, however careful monitoring of the population is recommended.
Collapse
Affiliation(s)
- Jamie McMurtrie
- Cefas Weymouth Laboratory, Centre for Environment, Fisheries and Aquaculture Science, Weymouth DT4 8UB, UK
| | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
4-Hydroxyphenylpyruvate Dioxygenase Thermolability Is Responsible for Temperature-Dependent Melanogenesis in Aeromonas salmonicida subsp. salmonicida. Appl Environ Microbiol 2019; 85:AEM.01926-18. [PMID: 30341077 DOI: 10.1128/aem.01926-18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 10/09/2018] [Indexed: 12/17/2022] Open
Abstract
Aeromonas salmonicida subsp. salmonicida is a major pathogen affecting fisheries worldwide and is a well-known pigmented member of the Aeromonas genus. This subspecies produces melanin at ≤22°C. However, melanogenesis decreases as the culture temperature increases and is completely suppressed at 30°C to 35°C, while bacterial growth is unaffected. The mechanism and biological significance of this temperature-dependent melanogenesis remain unclear. Heterologous expression of an A. salmonicida subsp. salmonicida 4-hydroxyphenylpyruvate dioxygenase (HppD), the most critical enzyme in the homogentisic acid (HGA)-melanin synthesis pathway, results in thermosensitive pigmentation in Escherichia coli, suggesting that HppD plays a key role in this process. In this study, we demonstrated that the thermolability of HppD is responsible for the temperature-dependent melanization of A. salmonicida subsp. salmonicida Substitutions of three residues, S18T, P103Q, and L119P, in A. salmonicida subsp. salmonicida HppD increased the thermostability of this enzyme and resulted in temperature-independent melanogenesis. Moreover, the replacement of the corresponding residues in HppD from Aeromonas media strain WS, which forms pigment independent of temperature, with those of A. salmonicida subsp. salmonicida HppD resulted in thermosensitive melanogenesis. A structural analysis suggested that mutations at these sites, especially at position P103, strengthen the secondary structure of HppD and greatly improve its thermal stability. Additionally, we found that the HppD sequences of all A. salmonicida subsp. salmonicida isolates were identical and that two of the three residues were clearly distinct from those of other Aeromonas strains.IMPORTANCE Aeromonas salmonicida subsp. salmonicida is the causative agent of furunculosis, a bacterial septicemia of cold-water fish of the Salmonidae family. Although other Aeromonas species can produce melanin, A. salmonicida subsp. salmonicida is the only member of this genus that has been reported to exhibit temperature-dependent melanization. Here, we demonstrated that thermosensitive melanogenesis in A. salmonicida subsp. salmonicida strains is due to the thermolability of 4-hydroxyphenylpyruvate dioxygenase (HppD). Additionally, we confirmed that this thermolabile HppD exhibited higher activity at low temperatures than its mesophilic homologues, suggesting this as an adaptive strategy of this enzyme to the psychrophilic lifestyle of A. salmonicida subsp. salmonicida The strictly conserved hppD sequences among A. salmonicida subsp. salmonicida isolates and the specific possession of P103 and L119 residues could be used as a reference for the identification of A. salmonicida subsp. salmonicida isolates.
Collapse
|
28
|
Brooker AJ, Papadopoulou A, Gutierrez C, Rey S, Davie A, Migaud H. Sustainable production and use of cleaner fish for the biological control of sea lice: recent advances and current challenges. Vet Rec 2018; 183:383. [DOI: 10.1136/vr.104966] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 06/26/2018] [Accepted: 07/06/2018] [Indexed: 11/04/2022]
Affiliation(s)
- Adam J Brooker
- Institute of Aquaculture, University of Stirling; Stirling UK
| | | | | | - Sonia Rey
- Institute of Aquaculture, University of Stirling; Stirling UK
| | - Andrew Davie
- Institute of Aquaculture, University of Stirling; Stirling UK
| | - Herve Migaud
- Institute of Aquaculture, University of Stirling; Stirling UK
| |
Collapse
|
29
|
Vercauteren M, De Swaef E, Declercq A, Bosseler L, Gulla S, Balboa S, Romalde JL, Devriese L, Polet H, Boyen F, Chiers K, Decostere A. First isolation of Vibrio tapetis and an atypical strain of Aeromonas salmonicida from skin ulcerations in common dab (Limanda limanda) in the North Sea. JOURNAL OF FISH DISEASES 2018; 41:329-335. [PMID: 29148593 DOI: 10.1111/jfd.12729] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 08/15/2017] [Indexed: 06/07/2023]
Abstract
Skin ulcerations rank amongst the most prevalent lesions affecting wild common dab (Limanda limanda) with an increase in prevalence of up to 3.5% in the Belgian part of the North Sea. A complex aetiology of these ulcerations is suspected, and many questions remain on the exact factors contributing to these lesions. To construct the aetiological spectrum of skin ulcerations in flatfish, a one-day monitoring campaign was undertaken in the North Sea. Fifteen fish presented with one or more ulcerations on the pigmented and/or non-pigmented side. Pathological features revealed various stages of ulcerations with loss of epidermal and dermal tissue, inflammatory infiltrates and degeneration of the myofibers bordering the ulceration, albeit in varying degrees. Upon bacteriological examination, pure cultures of Vibrio tapetis were retrieved in high numbers from five fish and of Aeromonas salmonicida in one fish. The V. tapetis isolates showed cross-reactivity with the sera against the representative strain of serotype O2 originating form a carpet-shell clam (Ruditapes descussatus). Moreover, the A. salmonicida isolates displayed a previously undescribed vapA gene sequence (A-layer type) with possible specificity towards common dab. Further research is necessary to pinpoint the exact role of these agents in the development of skin ulcerations in common dab.
Collapse
Affiliation(s)
- M Vercauteren
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - E De Swaef
- Department of Morphology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - A Declercq
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - L Bosseler
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - S Gulla
- Norwegian Veterinary Institute, Oslo, Norway
| | - S Balboa
- Department of Microbiology and Parasitology, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - J L Romalde
- Department of Microbiology and Parasitology, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - L Devriese
- Animal Sciences Unit - Aquatic Environment and Quality, Institute for Agricultural and Fisheries Research (ILVO), Ostend, Belgium
- Department of Environment and Health, Vrije Universiteit, Amsterdam, The Netherlands
| | - H Polet
- Animal Sciences Unit - Aquatic Environment and Quality, Institute for Agricultural and Fisheries Research (ILVO), Ostend, Belgium
| | - F Boyen
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - K Chiers
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - A Decostere
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| |
Collapse
|
30
|
Scholz F, Ruane NM, Morrissey T, Marcos-López M, Mitchell S, O'Connor I, Mirimin L, MacCarthy E, Rodger HD. Piscine myocarditis virus detected in corkwing wrasse (Symphodus melops) and ballan wrasse (Labrus bergylta). JOURNAL OF FISH DISEASES 2018; 41:147-152. [PMID: 28791724 DOI: 10.1111/jfd.12661] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 05/03/2017] [Accepted: 05/04/2017] [Indexed: 06/07/2023]
Affiliation(s)
- F Scholz
- FishVet Group Ireland, Oranmore, Co. Galway, Ireland
- Marine and Freshwater Research Centre, Galway-Mayo Institute of Technology, Galway, Ireland
| | - N M Ruane
- Fish Health Unit, Marine Institute, Oranmore, Co. Galway, Ireland
| | - T Morrissey
- Fish Health Unit, Marine Institute, Oranmore, Co. Galway, Ireland
| | - M Marcos-López
- FishVet Group Ireland, Oranmore, Co. Galway, Ireland
- Marine and Freshwater Research Centre, Galway-Mayo Institute of Technology, Galway, Ireland
| | - S Mitchell
- FishVet Group Ireland, Oranmore, Co. Galway, Ireland
| | - I O'Connor
- Marine and Freshwater Research Centre, Galway-Mayo Institute of Technology, Galway, Ireland
| | - L Mirimin
- Marine and Freshwater Research Centre, Galway-Mayo Institute of Technology, Galway, Ireland
| | - E MacCarthy
- Marine and Freshwater Research Centre, Galway-Mayo Institute of Technology, Galway, Ireland
| | - H D Rodger
- FishVet Group Ireland, Oranmore, Co. Galway, Ireland
| |
Collapse
|
31
|
Marcos-López M, Ruane NM, Scholz F, Bolton-Warberg M, Mitchell SO, Murphy O'Sullivan S, Irwin Moore A, Rodger HD. Piscirickettsia salmonis infection in cultured lumpfish (Cyclopterus lumpus L.). JOURNAL OF FISH DISEASES 2017; 40:1625-1634. [PMID: 28429818 DOI: 10.1111/jfd.12630] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 02/07/2017] [Accepted: 02/09/2017] [Indexed: 06/07/2023]
Abstract
A Piscirickettsia salmonis infection was diagnosed in lumpfish (Cyclopterus lumpus L.) juveniles held in a marine research facility on the west coast of Ireland. The main clinical signs and pathology included marked ascites, severe multifocal liver necrosis and severe diffuse inflammation and necrosis of the exocrine pancreas and peri-pancreatic adipose tissue. Numerous Piscirickettsia-like organisms were observed by histopathology in the affected organs, and the bacterial species was characterized by molecular analysis. Sequencing of the partial 16S rDNA gene and internal transcribed spacer region showed the lumpfish sequences to be closely related to previously identified Atlantic salmon (Salmo salar L.) sequences from Ireland. To the authors' knowledge, this is the first detection of P. salmonis in lumpfish worldwide. The infection is considered potentially significant in terms of lumpfish health and biosecurity.
Collapse
Affiliation(s)
| | - N M Ruane
- Fish Health Unit, Marine Institute, Oranmore, Co. Galway, Ireland
| | - F Scholz
- Fish Vet Group Ireland, Galway, Ireland
| | - M Bolton-Warberg
- Carna Research Station, Ryan Institute, NUIG, Carna, Co. Galway, Ireland
| | | | | | - A Irwin Moore
- Carna Research Station, Ryan Institute, NUIG, Carna, Co. Galway, Ireland
| | | |
Collapse
|
32
|
Rønneseth A, Haugland GT, Colquhoun DJ, Brudal E, Wergeland HI. Protection and antibody reactivity following vaccination of lumpfish (Cyclopterus lumpus L.) against atypical Aeromonas salmonicida. FISH & SHELLFISH IMMUNOLOGY 2017; 64:383-391. [PMID: 28344167 DOI: 10.1016/j.fsi.2017.03.040] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 03/01/2017] [Accepted: 03/22/2017] [Indexed: 06/06/2023]
Abstract
Atypical Aeromonas salmonicida is frequently associated with disease and mortality in farmed lumpfish (Cyclopterus lumpus L). Challenge experiments using different modes of exposure identified both high and low pathogenic isolates. Intraperitoneal vaccination induced production of high levels of specific antibodies particularly in fish given multiple injections. The immune sera contained antibodies cross reactive with both high and low pathogenic isolates. SDS-PAGE and LC/MSMS analyses showed that the highly virulent isolate expressed the virulence array protein (A-layer) while the less virulent isolate did not. Vaccines, containing the highly virulent isolate, formulated as a monovalent or as a trivalent vaccine, provided 73 and 60 relative percent survival (RPS) respectively, following intraperitoneal challenge. The detection of high levels of specific antibodies in immune sera and the protection provided by the test vaccines strongly indicate that it is possible to vaccinate lumpfish against atypical A. salmonicida and most probably also against other infectious bacterial diseases.
Collapse
Affiliation(s)
- Anita Rønneseth
- Department of Biology, University of Bergen, Bergen High-Technology Centre, PO Box 7803, NO-5020 Bergen, Norway.
| | - Gyri T Haugland
- Department of Biology, University of Bergen, Bergen High-Technology Centre, PO Box 7803, NO-5020 Bergen, Norway
| | - Duncan J Colquhoun
- Department of Biology, University of Bergen, Bergen High-Technology Centre, PO Box 7803, NO-5020 Bergen, Norway; Norwegian Veterinary Institute, Oslo, Norway
| | | | - Heidrun I Wergeland
- Department of Biology, University of Bergen, Bergen High-Technology Centre, PO Box 7803, NO-5020 Bergen, Norway
| |
Collapse
|
33
|
Bayliss SC, Verner-Jeffreys DW, Bartie KL, Aanensen DM, Sheppard SK, Adams A, Feil EJ. The Promise of Whole Genome Pathogen Sequencing for the Molecular Epidemiology of Emerging Aquaculture Pathogens. Front Microbiol 2017; 8:121. [PMID: 28217117 PMCID: PMC5290457 DOI: 10.3389/fmicb.2017.00121] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 01/17/2017] [Indexed: 01/23/2023] Open
Abstract
Aquaculture is the fastest growing food-producing sector, and the sustainability of this industry is critical both for global food security and economic welfare. The management of infectious disease represents a key challenge. Here, we discuss the opportunities afforded by whole genome sequencing of bacterial and viral pathogens of aquaculture to mitigate disease emergence and spread. We outline, by way of comparison, how sequencing technology is transforming the molecular epidemiology of pathogens of public health importance, emphasizing the importance of community-oriented databases and analysis tools.
Collapse
Affiliation(s)
- Sion C Bayliss
- The Milner Centre for Evolution, Department of Biology and Biochemistry, University of Bath Bath, UK
| | | | - Kerry L Bartie
- Institute of Aquaculture, University of Stirling Stirling, UK
| | - David M Aanensen
- Department of Infectious Disease Epidemiology, School of Public Health, Imperial College LondonLondon, UK; The Centre for Genomic Pathogen Surveillance, Wellcome Genome CampusCambridge, UK
| | - Samuel K Sheppard
- The Milner Centre for Evolution, Department of Biology and Biochemistry, University of Bath Bath, UK
| | - Alexandra Adams
- Institute of Aquaculture, University of Stirling Stirling, UK
| | - Edward J Feil
- The Milner Centre for Evolution, Department of Biology and Biochemistry, University of Bath Bath, UK
| |
Collapse
|
34
|
Biering E, Vaagnes Ø, Krossøy B, Gulla S, Colquhoun DJ. Challenge models for atypical Aeromonas salmonicida and Vibrio anguillarum in farmed Ballan wrasse (Labrus bergylta) and preliminary testing of a trial vaccine against atypical Aeromonas salmonicida. JOURNAL OF FISH DISEASES 2016; 39:1257-1261. [PMID: 26849912 DOI: 10.1111/jfd.12450] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 11/22/2015] [Accepted: 11/22/2015] [Indexed: 06/05/2023]
Affiliation(s)
- E Biering
- Norwegian Veterinary Institute, Norway
| | - Ø Vaagnes
- Norwegian Veterinary Institute, Norway
| | | | - S Gulla
- Norwegian Veterinary Institute, Norway
- Vaxxinova Norway, Bergen, Norway
| | | |
Collapse
|
35
|
Long M, Nielsen TK, Leisner JJ, Hansen LH, Shen ZX, Zhang QQ, Li A. Aeromonas salmonicidasubsp.salmonicidastrains isolated from Chinese freshwater fish contain a novel genomic island and possible regional-specific mobile genetic elements profiles. FEMS Microbiol Lett 2016; 363:fnw190. [DOI: 10.1093/femsle/fnw190] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/01/2016] [Indexed: 01/15/2023] Open
|
36
|
Gulla S, Duodu S, Nilsen A, Fossen I, Colquhoun DJ. Aeromonas salmonicida infection levels in pre- and post-stocked cleaner fish assessed by culture and an amended qPCR assay. JOURNAL OF FISH DISEASES 2016; 39:867-877. [PMID: 26514414 DOI: 10.1111/jfd.12420] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 08/28/2015] [Accepted: 08/28/2015] [Indexed: 06/05/2023]
Abstract
Due to increasing resistance to chemical therapeutants, the use of 'cleaner fish' (primarily wrasse, Labridae, species) has become popular in European salmon farming for biocontrol of the salmon louse, Lepeophtheirus salmonis (Krøyer). While being efficient de-licers, cleaner fish mortality levels in salmon cages are commonly high, and systemic bacterial infections constitute a major problem. Atypical furunculosis, caused by Aeromonas salmonicida A-layer types V and VI, is among the most common diagnoses reached in clinical investigations. A previously described real-time PCR (qPCR), targeting the A. salmonicida A-layer gene (vapA), was modified and validated for specific and sensitive detection of all presently recognized A-layer types of this bacterium. Before stocking and during episodes of increased mortality in salmon cages, cleaner fish (primarily wild-caught wrasse) were sampled and screened for A. salmonicida by qPCR and culture. Culture indicated that systemic bacterial infections are mainly contracted after salmon farm stocking, and qPCR revealed A. salmonicida prevalences of approximately 4% and 68% in pre- and post-stocked cleaner fish, respectively. This underpins A. salmonicida's relevance as a contributing factor to cleaner fish mortality and emphasizes the need for implementation of preventive measures (e.g. vaccination) if current levels of cleaner fish use are to be continued or expanded.
Collapse
Affiliation(s)
- S Gulla
- Norwegian Veterinary Institute, Oslo/Trondheim, Norway
- Vaxxinova Norway AS, Bergen, Norway
| | - S Duodu
- Norwegian Veterinary Institute, Oslo/Trondheim, Norway
| | - A Nilsen
- Norwegian Veterinary Institute, Oslo/Trondheim, Norway
| | - I Fossen
- Møreforskning AS, Kristiansund, Norway
| | - D J Colquhoun
- Norwegian Veterinary Institute, Oslo/Trondheim, Norway
- Institute for Biology, University of Bergen, Bergen, Norway
| |
Collapse
|
37
|
Gulla S, Sørum H, Vågnes Ø, Colquhoun DJ. Phylogenetic analysis and serotyping of Vibrio splendidus-related bacteria isolated from salmon farm cleaner fish. DISEASES OF AQUATIC ORGANISMS 2015; 117:121-131. [PMID: 26648104 DOI: 10.3354/dao02938] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Cleaner fish, i.e. various wrasse (Labridae) species and lumpsucker Cyclopterus lumpus, are to an increasing extent used for biocontrol of the salmon louse Lepeophtheirus salmonis in European salmon farming. Although efficient de-licers, cleaner fish mortality levels in salmon farms are often high. Bacterial infections are common, and Vibrio splendidus-related strains are frequently identified during diagnostic investigations. The population structure of 112 V. splendidus-related isolates, derived primarily from wrasse species, was investigated by means of multilocus sequence analysis using 5 housekeeping genes (rpoD, ftsZ, pyrH, rpoA and atpA). Most isolates were found to be closely related to the V. splendidus type strain, yet displayed extensive genetic microdiversity. Slide agglutination testing using polyclonal rabbit antisera further indicated O-antigen variability. Intra-outbreak genetic and antigenic diversity suggests direct infection from seawater, rather than fish-to-fish transmission, as the main route of infection. The variable nature of isolates involved complicates qualified selection of representative candidate strains, e.g. for infection and vaccine trials.
Collapse
Affiliation(s)
- Snorre Gulla
- Norwegian Veterinary Institute, PO Box 750 Sentrum, 0106 Oslo, Norway
| | | | | | | |
Collapse
|