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Santibáñez N, Vega M, Pérez T, Enriquez R, Escalona CE, Oliver C, Romero A. In vitro effects of phytogenic feed additive on Piscirickettsia salmonis growth and biofilm formation. J Fish Dis 2024; 47:e13913. [PMID: 38421380 DOI: 10.1111/jfd.13913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 12/15/2023] [Accepted: 12/20/2023] [Indexed: 03/02/2024]
Abstract
Piscirickettsiosis is the main cause of mortality in salmonids of commercial importance in Chile, which is caused by Piscirickettsia salmonis, a Gram-negative, γ-proteobacteria that can produce biofilm as one of its virulence factors. The Chilean salmon industry uses large amounts of antibiotics to control piscirickettsiosis outbreaks, which has raised concern about its environmental impact and the potential to induce antibiotic resistance. Thus, the use of phytogenic feed additives (PFA) with antibacterial activity emerges as an interesting alternative to antimicrobials. Our study describes the antimicrobial action of an Andrographis paniculate-extracted PFA on P. salmonis planktonic growth and biofilm formation. We observed complete inhibition of planktonic and biofilm growth with 500 and 400 μg/mL of PFA for P. salmonis LF-89 and EM-90-like strains, respectively. Furthermore, 500 μg/mL of PFA was bactericidal for both evaluated bacterial strains. Sub-inhibitory doses of PFA increase the transcript levels of stress (groEL), biofilm (pslD), and efflux pump (acrB) genes for both P. salmonis strains in planktonic and sessile conditions. In conclusion, our results demonstrate the antibacterial effect of PFA against P. salmonis in vitro, highlighting the potential of PFA as an alternative to control Piscirickettsiosis.
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Affiliation(s)
- Natacha Santibáñez
- Laboratorio de Inmunología y Estrés de Organismos Acuáticos, Instituto de Patología Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
- Interdisciplinary Center for Aquaculture Research (INCAR), Centro FONDAP, Concepción, Chile
| | - Matías Vega
- Laboratorio de Inmunología y Estrés de Organismos Acuáticos, Instituto de Patología Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
- Interdisciplinary Center for Aquaculture Research (INCAR), Centro FONDAP, Concepción, Chile
| | - Tatiana Pérez
- Laboratorio de Inmunología y Estrés de Organismos Acuáticos, Instituto de Patología Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
- Interdisciplinary Center for Aquaculture Research (INCAR), Centro FONDAP, Concepción, Chile
| | - Ricardo Enriquez
- Laboratorio de Inmunología y Estrés de Organismos Acuáticos, Instituto de Patología Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Carla Estefanía Escalona
- Laboratorio de Inmunología y Estrés de Organismos Acuáticos, Instituto de Patología Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
- Interdisciplinary Center for Aquaculture Research (INCAR), Centro FONDAP, Concepción, Chile
| | - Cristian Oliver
- Laboratorio de Inmunología y Estrés de Organismos Acuáticos, Instituto de Patología Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Alex Romero
- Laboratorio de Inmunología y Estrés de Organismos Acuáticos, Instituto de Patología Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
- Interdisciplinary Center for Aquaculture Research (INCAR), Centro FONDAP, Concepción, Chile
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Oliver C, Ruiz P, Vidal JM, Carrasco C, Escalona CE, Barros J, Sepúlveda D, Urrutia H, Romero A. Effect of florfenicol on Piscirickettsia salmonis biofilm formed in materials used in salmonid nets, nylon and high-density polyethylene. J Fish Dis 2024; 47:e13862. [PMID: 37776076 DOI: 10.1111/jfd.13862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 08/29/2023] [Accepted: 09/05/2023] [Indexed: 10/01/2023]
Abstract
Piscirickettsiosis is the most prevalent bacterial disease affecting seawater salmon in Chilean salmon industry. Antibiotic therapy is the first alternative to counteract infections caused by Piscirickettsia salmonis. The presence of bacterial biofilms on materials commonly used in salmon farming may be critical for understanding the bacterial persistence in the environment. In the present study, the CDC Biofilm Reactor® was used to investigate the effect of sub- and over-MIC of florfenicol on both the pre-formed biofilm and the biofilm formation by P. salmonis under the antibiotic stimuli on Nylon and high-density polyethylene (HDPE) surfaces. This study demonstrated that FLO, at sub- and over-MIC doses, decreases biofilm-embedded live bacteria in the P. salmonis isolates evaluated. However, it was shown that in the P. salmonis Ps007 strain the presence of sub-MIC of FLO reduced its biofilm formation on HDPE surfaces; however, biofilm persists on Nylon surfaces. These results demonstrated that P. salmonis isolates behave differently against FLO and also, depending on the surface materials. Therefore, it remains a challenge to find an effective strategy to control the biofilm formation of P. salmonis, and certainly other marine pathogens that affect the sustainability of the Chilean salmon industry.
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Affiliation(s)
- Cristian Oliver
- Laboratorio de Inmunología y Estrés de Organismos Acuáticos, Instituto de Patología Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Pamela Ruiz
- Laboratorio de Biopelículas y Microbiología Ambiental, Centro de Biotecnología, Universidad de Concepción, Concepción, Chile
- Departamento de Ciencias Biológicas, Facultad de Ciencias de la Vida, Universidad Andres Bello, Talcahuano, Chile
| | - José Miguel Vidal
- Laboratorio de Biopelículas y Microbiología Ambiental, Centro de Biotecnología, Universidad de Concepción, Concepción, Chile
- Departamento de Investigación y Desarrollo, Ecombio Limitada, Concepción, Chile
| | - Carlos Carrasco
- Laboratorio de Biopelículas y Microbiología Ambiental, Centro de Biotecnología, Universidad de Concepción, Concepción, Chile
| | - Carla Estefanía Escalona
- Laboratorio de Inmunología y Estrés de Organismos Acuáticos, Instituto de Patología Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Javier Barros
- Departamento de Investigación y Desarrollo, Micbiotech Spa, Concepción, Chile
| | - Daniela Sepúlveda
- Laboratorio de Biopelículas y Microbiología Ambiental, Centro de Biotecnología, Universidad de Concepción, Concepción, Chile
| | - Homero Urrutia
- Laboratorio de Biopelículas y Microbiología Ambiental, Centro de Biotecnología, Universidad de Concepción, Concepción, Chile
- Departamento de Microbiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Alex Romero
- Laboratorio de Inmunología y Estrés de Organismos Acuáticos, Instituto de Patología Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
- Interdisciplinary Center for Aquaculture Research, (INCAR), Concepción, Chile
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Bustos P, Figueroa C, Cádiz B, Santander T, Dixon B, Gallardo JA, Conejeros P. Immune response induced by coinfection of the sea louse Caligus rogercresseyi and the intracellular bacteria Piscirickettsia salmonis in vaccinated Atlantic salmon. J Fish Dis 2023; 46:1337-1342. [PMID: 37675858 DOI: 10.1111/jfd.13851] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 08/03/2023] [Accepted: 08/07/2023] [Indexed: 09/08/2023]
Abstract
Recently, we showed that Atlantic salmon vaccinated against Piscirickettsia salmonis lose their protection upon coinfection with Caligus rogercresseyi (sea lice). However, the causes of the overriding effect of C. rogercresseyi infection have not been elucidated, and the molecular basis of the cellular and humoral immune responses upon C. rogercresseyi infection has not been described for vaccinated salmon. Therefore, we studied changes in the transcription of immune genes in vaccinated Atlantic salmon that were experimentally challenged by co-infecting them with C. rogercresseyi and P. salmonis. In general, coinfection treatments showed immune gene expression similar to treatments with a single P. salmonis infection, showing a decreased cellular response. However, a high variance was found between individual fish in the case of crucial cellular immune genes, with a few fish reacting overwhelmingly highly compared to the majority. This supports our previous findings on vaccination response variation and reinforces the idea that vaccination failures in the field might be caused by an overwhelming amount of vaccinated fish that display a deficient immune response to the infection.
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Affiliation(s)
- Paulina Bustos
- Laboratorio de Biotecnología Acuática y Genómica Reproductiva (LABYGER), Facultad de Ciencias, Instituto de Biología, Universidad de Valparaíso, Valparaíso, Chile
- Laboratorio de Biotecnología Molecular, Facultad de Ciencias, Instituto de Biología, Universidad de Valparaíso, Valparaíso, Chile
- Centro de Investigación y Gestión de Recursos Naturales (CIGREN), Universidad de Valparaíso, Valparaíso, Chile
| | - Carolina Figueroa
- Escuela de Ciencias del Mar, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
| | - Bárbara Cádiz
- Laboratorio de Biotecnología Molecular, Facultad de Ciencias, Instituto de Biología, Universidad de Valparaíso, Valparaíso, Chile
| | - Tamara Santander
- Laboratorio de Biotecnología Molecular, Facultad de Ciencias, Instituto de Biología, Universidad de Valparaíso, Valparaíso, Chile
| | - Brian Dixon
- Faculty of Science, University of Waterloo, Waterloo, Ontario, Canada
| | - José A Gallardo
- Escuela de Ciencias del Mar, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
| | - Pablo Conejeros
- Laboratorio de Biotecnología Molecular, Facultad de Ciencias, Instituto de Biología, Universidad de Valparaíso, Valparaíso, Chile
- Centro de Investigación y Gestión de Recursos Naturales (CIGREN), Universidad de Valparaíso, Valparaíso, Chile
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Valenzuela B, Benavides A, Leyton F, Moreno F, Cortés M, Ibacache JA. Evaluation of bactericidal activity of 7-arylaminoisoquinolin-5,8-quinones against Piscirickettsia salmonis. J Fish Dis 2023; 46:85-89. [PMID: 36179045 DOI: 10.1111/jfd.13720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 09/14/2022] [Accepted: 09/15/2022] [Indexed: 06/16/2023]
Affiliation(s)
- Beatriz Valenzuela
- Environmental Sciences Department, Chemistry and Biology Faculty, Natural Product Chemistry Laboratory, Aquatic Biotechnology Center, University of Santiago of Chile, Santiago, Chile
| | - Almendra Benavides
- Environmental Sciences Department, Chemistry and Biology Faculty, Natural Product Chemistry Laboratory, Aquatic Biotechnology Center, University of Santiago of Chile, Santiago, Chile
| | - Francisco Leyton
- Environmental Sciences Department, Chemistry and Biology Faculty, Organic Synthesis Laboratory, University of Santiago of Chile, Santiago, Chile
| | - Franco Moreno
- Environmental Sciences Department, Chemistry and Biology Faculty, Organic Synthesis Laboratory, University of Santiago of Chile, Santiago, Chile
| | - Marcos Cortés
- Biology Department, Chemistry and Biology Faculty, Immunology Laboratory, Aquatic Biotechnology Center, University of Santiago of Chile, Santiago, Chile
| | - Juana A Ibacache
- Environmental Sciences Department, Chemistry and Biology Faculty, Organic Synthesis Laboratory, University of Santiago of Chile, Santiago, Chile
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5
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Vidal JM, Ruiz P, Carrasco C, Barros J, Sepúlveda D, Ruiz-Tagle N, Romero A, Urrutia H, Oliver C. Piscirickettsia salmonis forms a biofilm on nylon surface using a CDC Biofilm Reactor. J Fish Dis 2022; 45:1099-1107. [PMID: 35543448 DOI: 10.1111/jfd.13632] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 04/18/2022] [Accepted: 04/21/2022] [Indexed: 06/14/2023]
Abstract
Research into Piscirickettsia salmonis biofilms on materials commonly used in salmon farming is crucial for understanding its persistence and virulence. We used the CDC Biofilm Reactor to investigate P. salmonis (LF-89 and EM-90) biofilm formation on Nylon, Stainless steel (316L), Polycarbonate and High-Density Polyethylene (HDPE) surfaces. After 144 h of biofilm visualization by scanning confocal laser microscopy under batch growth conditions, Nylon coupons generated the greatest biofilm formation and coverage compared to Stainless steel (316L), Polycarbonate and HDPE. Additionally, P. salmonis biofilm formation on Nylon was significantly greater (p ≤ .01) than Stainless steel (316L), Polycarbonate and HDPE at 288 h. We used Nylon coupons to determine the kinetic parameters of the planktonic and biofilm phases of P. salmonis. The two strains had similar latencies in the planktonic phase; however, LF-89 maximum growth was 2.5 orders of magnitude higher (Log cell ml-1 ). Additionally, LF-89 had a specified growth rate (µmax) of 0.0177 ± 0.006 h-1 and a generation time of 39.2 h. This study contributes to a deeper understanding of the biofilm formation by P. salmonis and elucidates the impact of the biofilm on aquaculture systems.
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Affiliation(s)
- José Miguel Vidal
- Laboratorio de Biopelículas y Microbiología Ambiental, Centro de Biotecnología, Universidad de Concepción, Concepción, Chile
- Departamento de Investigación y Desarrollo, Ecombio limitada, Concepción, Chile
| | - Pamela Ruiz
- Laboratorio de Biopelículas y Microbiología Ambiental, Centro de Biotecnología, Universidad de Concepción, Concepción, Chile
- Departamento de Ciencias Biológicas, Facultad de Ciencias de la Vida, Universidad Andres Bello, Talcahuano, Chile
| | - Carlos Carrasco
- Laboratorio de Biopelículas y Microbiología Ambiental, Centro de Biotecnología, Universidad de Concepción, Concepción, Chile
| | - Javier Barros
- Departamento de Investigación y Desarrollo, Micbiotech spa, Concepción, Chile
| | - Daniela Sepúlveda
- Laboratorio de Biopelículas y Microbiología Ambiental, Centro de Biotecnología, Universidad de Concepción, Concepción, Chile
| | - Nathaly Ruiz-Tagle
- Laboratorio de Biopelículas y Microbiología Ambiental, Centro de Biotecnología, Universidad de Concepción, Concepción, Chile
| | - Alex Romero
- Laboratorio de Inmunología y Estrés de Organismos Acuáticos, Instituto de Patología Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
- Interdisciplinary Center for Aquaculture Research, INCAR, Concepción, Chile
| | - Homero Urrutia
- Laboratorio de Biopelículas y Microbiología Ambiental, Centro de Biotecnología, Universidad de Concepción, Concepción, Chile
- Departamento de Microbiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Cristian Oliver
- Laboratorio de Inmunología y Estrés de Organismos Acuáticos, Instituto de Patología Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
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Zrnčić S, Vendramin N, Boutrup TS, Boye M, Madsen L, Nonneman B, Brnić D, Oraić D. First description and diagnostics of disease caused by Piscirickettsia salmonis in farmed European sea bass (Dicentrarchus labrax Linnaeus) from Croatia. J Fish Dis 2021; 44:1033-1042. [PMID: 33754342 DOI: 10.1111/jfd.13366] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 02/27/2021] [Accepted: 03/01/2021] [Indexed: 06/12/2023]
Abstract
During the winter of 2013 and 2016, several Croatian fish farms experienced mortalities in the fry of European sea bass, Dicentrarchus labrax. Affected fish showed abnormal swimming behaviour and reduced appetite, and death ensued several days after the onset of clinical signs of disease. Necropsy revealed pale liver, empty digestive tract, distended gall bladder, and hyperaemia and congestion of the meninges. Routine bacteriological examination tested negative, and virological examination ruled out nodavirus infection. Histological examination revealed multifocal necrosis and extensive inflammation in the brain with abundant cellular debris in the ventricles. Inflammatory cells displayed intra-cytoplasmic basophilic vacuoles leading to suspicion of Piscirickettsia salmonis infection. Fluorescent in situ hybridization using an oligonucleotide probe targeting Domain Bacterium applied to tissue sections tested positive. The pathogen was identified by 16S rRNA gene sequencing of brain material, and the sequence showed 99% similarity with P. salmonis. This result enabled the design of an oligonucleotide probe specifically targeting P. salmonis. In 2016, P. salmonis was successfully isolated on CHAB from the brain of an affected specimen and identified using 16S rRNA gene sequencing and MALDI-TOF. This study describes the first outbreak of disease caused by P. salmonis in sea bass in Croatia, while new diagnostic tools will enable further research on its epidemiology and pathogenicity.
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Affiliation(s)
| | - Niccolò Vendramin
- Unit for Fish and Shellfish Diseases, National Institute of Aquatic Resources, DTU AQUA, Kgs Lyngby, Denmark
| | | | - Mette Boye
- Norwegian Veterinary Institute, Oslo, Norway
| | - Lone Madsen
- Unit for Fish and Shellfish Diseases, National Institute of Aquatic Resources, DTU AQUA, Kgs Lyngby, Denmark
| | - Bettina Nonneman
- Unit for Fish and Shellfish Diseases, National Institute of Aquatic Resources, DTU AQUA, Kgs Lyngby, Denmark
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Quintanilla JC, González MP, García JP, Olmos P, Contreras-Lynch S. Horizontal transmission of Piscirickettsia salmonis from the wild sub-Antarctic notothenioid fish Eleginops maclovinus to rainbow trout (Oncorhynchus mykiss) under experimental conditions. J Fish Dis 2021; 44:993-1004. [PMID: 33675091 DOI: 10.1111/jfd.13360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 02/11/2021] [Accepted: 02/12/2021] [Indexed: 06/12/2023]
Abstract
Piscirickettsia salmonis is the aetiological agent of piscirickettsiosis, a bacterial disease that affects farmed salmonids, causing high mortalities and significant economic losses in the Chilean salmon farm industry. Given the Chilean native fish species Patagonian blenny, Eleginops maclovinus, lives in the vicinity of salmon farms, it is relevant to clarify the epidemiological role that this species could play in the transmission and/or dissemination of this pathogen. This study aimed to evaluate the bidirectional transmission of P. salmonis between the Patagonian blenny and Oncorhynchus mykiss (rainbow trout), via a cohabitation challenge model. The results of this study demonstrated the transmission of the bacteria from Patagonian blennies to rainbow trout, considering the specific mortality in cohabitant rainbow trout, reaching 46%: the necropsy of these specimens, evidencing the characteristic pathological lesions of the disease and the positive results of the qPCR analysis for P. salmonis, in the same individuals. In contrast, no mortalities of Patagonian blenny specimens were recorded in the challenged experimental groups. This study is the first report showing the horizontal transmission of P. salmonis from a native non-salmonid species, such as the Patagonian blenny, to a salmonid species, generating the disease and specific mortality in rainbow trout, using a cohabitation challenge.
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Affiliation(s)
- Juan Carlos Quintanilla
- Departamento de Salud Hidrobiológica, División de Investigación en Acuicultura, Instituto de Fomento Pesquero, Puerto Montt, Chile
| | - Margarita P González
- Departamento de Salud Hidrobiológica, División de Investigación en Acuicultura, Instituto de Fomento Pesquero, Puerto Montt, Chile
| | - Juan Pablo García
- Departamento de Salud Hidrobiológica, División de Investigación en Acuicultura, Instituto de Fomento Pesquero, Puerto Montt, Chile
| | - Paola Olmos
- Departamento de Salud Hidrobiológica, División de Investigación en Acuicultura, Instituto de Fomento Pesquero, Puerto Montt, Chile
| | - Sergio Contreras-Lynch
- Departamento de Salud Hidrobiológica, División de Investigación en Acuicultura, Instituto de Fomento Pesquero, Puerto Montt, Chile
- Doctorado en Acuicultura, Programa Cooperativo Universidad de Chile, Universidad Católica del Norte, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
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Levipan HA, Avendaño-Herrera R. Assessing the impacts of skin mucus from Salmo salar and Oncorhynchus mykiss on the growth and in vitro infectivity of the fish pathogen Piscirickettsia salmonis. J Fish Dis 2021; 44:181-190. [PMID: 33006764 DOI: 10.1111/jfd.13275] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 09/03/2020] [Accepted: 09/04/2020] [Indexed: 06/11/2023]
Abstract
Piscirickettsiosis is a fish disease caused by the facultative intracellular bacterium, Piscirickettsia salmonis. Even though entry routes of P. salmonis in fish are not fully clear yet, the skin seems to be the main portal in some salmonid species. Despite the importance of fish mucous skin barrier in fighting waterborne pathogens, the interaction between salmonid skin mucus and the bacterium is unknown. This study seeks to determine the in vitro changes in the growth of two Chilean P. salmonis strains (LF-89-like and EM-90-like genotypes) and the type strain LF-89T under exposures to skin mucus from Salmo salar and Oncorhynchus mykiss, as well as changes in the cytotoxic effect of P. salmonis on the SHK-1 cells following exposures. The results suggest that the growth of three P. salmonis strains was not significantly negatively affected under exposures to skin mucus (adjusted at 100 μg total protein ml-1 ) of O. mykiss (69 ± 18 U lysozyme ml-1 ) and S. salar (48 ± 33 U lysozyme ml-1 ) over time. However, the cytotoxic effect of P. salmonis, pre-exposed to salmonid skin mucus, on the SHK-1 cell line was reliably identified only towards the end of the incubation period, suggesting that the mucus had a delaying effect on the cytotoxic response of the cell line to the bacterium. These results represent a baseline knowledge to open new avenues of research intended to understand how P. salmonis faces the fish mucous skin barrier.
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Affiliation(s)
- Héctor A Levipan
- Departamento de Biología, Facultad de Ciencias Naturales y Exactas, Universidad de Playa Ancha, Valparaíso, Chile
| | - Ruben Avendaño-Herrera
- Laboratorio de Patología de Organismos Acuáticos y Biotecnología Acuícola, Departamento de Ciencias Biológicas, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Viña del Mar, Chile
- Interdisciplinary Center for Aquaculture Research, Universidad Andrés Bello, Viña del Mar, Chile
- Centro de Investigación Marina Quintay (CIMARQ), Universidad Andrés Bello, Quintay, Chile
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Long A, Goodall A, Jones SR. Development of a Piscirickettsia salmonis immersion challenge model to investigate the comparative susceptibility of three salmon species. J Fish Dis 2021; 44:1-9. [PMID: 33067883 PMCID: PMC7756497 DOI: 10.1111/jfd.13261] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 08/17/2020] [Accepted: 08/18/2020] [Indexed: 05/03/2023]
Abstract
Piscirickettsia salmonis, the aetiological agent of salmonid rickettsial septicaemia (SRS), is a global pathogen of wild and cultured marine salmonids. Here, we describe the development and application of a reproducible, standardized immersion challenge model to induce clinical SRS in juvenile pink (Oncorhynchus gorbuscha), Atlantic (Salmo salar) and sockeye salmon (O. nerka). Following a 1-hr immersion in 105 colony-forming units/ml, cumulative mortality in Atlantic salmon was 63.2% while mortality in sockeye salmon was 10%. Prevalence and levels of the bacterium in kidney prior to onset of mortality were lower in sockeye compared with Atlantic or pink salmon. The timing and magnitude of bacterial shedding were estimated from water samples collected during the exposure trials. Shedding was estimated to be 82-fold higher in Atlantic salmon as compared to sockeye salmon and peaked in the Atlantic salmon trial at 36 d post-immersion. These data suggest sockeye salmon are less susceptible to P. salmonis than Atlantic or pink salmon. Finally, skin lesions were observed on infected fish during all trials, often in the absence of detectable infection in kidney. As a result, we hypothesize that skin is the primary point of entry for P. salmonis during the immersion challenge.
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Affiliation(s)
- Amy Long
- Fisheries and Ocean CanadaNanaimoBCCanada
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Laurin E, Gardner IA, Peña A, Rozas-Serri M, Gayosa J, Neumann Heise J, Mardones FO. Bayesian estimation of diagnostic sensitivity and specificity of a qPCR and a bacteriological culture method for Piscirickettsia salmonis in farmed Atlantic salmon (Salmo salar L.) in Chile. J Fish Dis 2020; 43:1167-1175. [PMID: 32716071 DOI: 10.1111/jfd.13226] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 06/30/2020] [Accepted: 07/02/2020] [Indexed: 06/11/2023]
Abstract
Early detection of piscirickettsiosis is an important purpose of government- and industry-based surveillance for the disease in Atlantic salmon farms in Chile. Real-time qPCRs are currently used for surveillance because bacterial isolation is inadequately sensitive or rapid enough for routine use. Since no perfect tests exist, we used Bayesian latent class models to estimate diagnostic sensitivity (DSe) and specificity (DSp) of qPCR and culture using separate two-test, single-population models for three farms (n = 148, 151, 44). Informative priors were used for DSp (culture (beta(999,1); qPCR (beta(98,2)), and flat priors (beta 1,1) for DSe and prevalence. Models were run for liver and kidney tissues combined and separately, based on the presence of selected gross-pathological signs. Across all models, qPCR DSe was 5- to 30-fold greater than for culture. Combined-tissue qPCR median DSe was highest in Farm 3 (sampled during P. salmonis outbreak (DSe = 97.6%)) versus Farm 1 (DSe = 85.6%) or Farm 2 (DSe = 83.5%), both sampled before clinical disease. Median DSe of qPCR was similar for liver and kidney, but higher when gross-pathological signs were evident at necropsy. High DSe and DSp and rapid turnaround-time indicate that the qPCR is fit for surveillance programmes and diagnosis during an outbreak. Targeted testing of salmon with gross-pathological signs can enhance DSe.
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Affiliation(s)
- Emilie Laurin
- Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
| | - Ian A Gardner
- Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
| | - Andrea Peña
- Pathovet Laboratory Ltd, Puerto Montt, Chile
| | | | | | | | - Fernando O Mardones
- School of Veterinary Medicine, Pontifical Catholic University, Santiago, Chile
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11
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Soto-Dávila M, Martinez D, Oyarzún R, Pontigo JP, Vargas-Lagos C, Morera FJ, Saravia J, Zanuzzo F, Vargas-Chacoff L. Intermediary metabolic response and gene transcription modulation on the Sub-Antarctic notothenioid Eleginops maclovinus (Valenciennes, 1930) injected with two strains of Piscirickettsia salmonis. J Fish Dis 2020; 43:111-127. [PMID: 31709576 DOI: 10.1111/jfd.13107] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 10/01/2019] [Accepted: 10/03/2019] [Indexed: 06/10/2023]
Abstract
Pathogen interactions with cultured fish populations are well studied, but their effects on native fishes have not been characterized. In Chile, the disease caused by bacterial species Piscirickettsia salmonis represents one of the main issues and is considered to be one of the important pathogens in the field of aquaculture. They have been found to infect native fish. Therefore, it is necessary to understand the impact of P. salmonis on native species of local commercial value, as well as the potential impact associated with the emergence of antibiotic-resistant strains of P. salmonis. Due to this purpose, the native fish Eleginops maclovinus was used in our study. Fish were randomly distributed in tanks and intraperitoneally inoculated with two strains of P. salmonis. No mortality was recorded during the experiment. Cortisol, glucose and total α-amino acid levels increased in fish injected with AUSTRAL-005 strain compared to sham-injected and LF-89-inoculated fish. Moreover, results showed an increase in the activity of carbohydrates and lipids metabolism in liver; and an increase in the carbohydrates, lipids and total α-amino acid metabolism in muscle after injection with AUSTRAL-005. Our results suggest that P. salmonis modulates the physiology of E. maclovinus and the physiological impact increase in the presence of the antibiotic-resistant strain AUSTRAL-005.
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Affiliation(s)
- Manuel Soto-Dávila
- Instituto de Ciencias Marinas y Limnológicas, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
- Centro Fondap de Investigación de Altas Latitudes (IDEAL), Universidad Austral de Chile, Valdivia, Chile
| | - Danixa Martinez
- Instituto de Ciencias Marinas y Limnológicas, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
- Centro Fondap de Investigación de Altas Latitudes (IDEAL), Universidad Austral de Chile, Valdivia, Chile
| | - Ricardo Oyarzún
- Instituto de Ciencias Marinas y Limnológicas, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
- Centro Fondap de Investigación de Altas Latitudes (IDEAL), Universidad Austral de Chile, Valdivia, Chile
- Programa de Doctorado en Ciencias de la Acuicultura, Universidad Austral de Chile, Puerto Montt, Chile
| | - Juan P Pontigo
- Instituto de Ciencias Marinas y Limnológicas, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
| | - Carolina Vargas-Lagos
- Instituto de Ciencias Marinas y Limnológicas, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
- Centro Fondap de Investigación de Altas Latitudes (IDEAL), Universidad Austral de Chile, Valdivia, Chile
- Interdisciplinary Center for Aquaculture Research (INCAR), Concepción, Chile
| | - Francisco J Morera
- Instituto de Farmacología y Morfofisiología, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Julia Saravia
- Instituto de Ciencias Marinas y Limnológicas, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
- Centro Fondap de Investigación de Altas Latitudes (IDEAL), Universidad Austral de Chile, Valdivia, Chile
- Programa de Doctorado en Ciencias de la Acuicultura, Universidad Austral de Chile, Puerto Montt, Chile
| | - Fábio Zanuzzo
- Department of Ocean Sciences, Faculty of Sciences, Memorial University, St. John's, NL, Canada
| | - Luis Vargas-Chacoff
- Instituto de Ciencias Marinas y Limnológicas, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
- Centro Fondap de Investigación de Altas Latitudes (IDEAL), Universidad Austral de Chile, Valdivia, Chile
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12
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Meza K, Inami M, Dalum AS, Lund H, Bjelland AM, Sørum H, Løvoll M. Comparative evaluation of experimental challenge by intraperitoneal injection and cohabitation of Atlantic salmon (Salmo salar L) after vaccination against Piscirickettsia salmonis (EM90-like). J Fish Dis 2019; 42:1713-1730. [PMID: 31625186 DOI: 10.1111/jfd.13091] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 08/30/2019] [Accepted: 09/03/2019] [Indexed: 06/10/2023]
Abstract
The Chilean aquaculture has been challenged for years by piscirickettsiosis. A common prophylactic measurement to try to reduce the impact from this disease is vaccination, but the development of vaccines that induce satisfactory protection of the fish in the field has so far not been successful. Experimental challenge models are used to test vaccine efficacy. The aim of this study was to evaluate the performance of experimental vaccines after challenge by the two most widely used challenge routes, intraperitoneal injection and cohabitation. A total of 1,120 Atlantic salmon were vaccinated with non-commercial experimental vaccines with increasing amounts of an inactivated Piscirickettsia salmonis EM90-like isolate. Differences in mortality, macroscopic and microscopic pathological changes, bacterial load and immune gene expression were compared after challenge by different routes. The results revealed a similar progression of the diseases after challenge by both routes and no gross differences reflecting the efficacy of the vaccines could be identified. The analysis of the immune genes suggests a possible suppression of the cellular immunity by CD8 T cell and with this stimulation of bacterial survival and replication. Comparative studies of experimental challenge models are valuable with regard to identifying the best model to mimic real-life conditions and vaccines' performance.
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Affiliation(s)
- Karla Meza
- VESO Vikan, Namsos, Norway
- Norwegian University of Life Sciences (NMBU), Faculty of Veterinary Medicine, Oslo, Norway
| | | | | | - Hege Lund
- Norwegian University of Life Sciences (NMBU), Faculty of Veterinary Medicine, Oslo, Norway
| | - Ane M Bjelland
- Norwegian University of Life Sciences (NMBU), Faculty of Veterinary Medicine, Oslo, Norway
| | - Henning Sørum
- Norwegian University of Life Sciences (NMBU), Faculty of Veterinary Medicine, Oslo, Norway
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13
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Meza K, Inami M, Dalum AS, Bjelland AM, Sørum H, Løvoll M. Development of piscirickettsiosis in Atlantic salmon (Salmo salar L.) smolts after intraperitoneal and cohabitant challenge using an EM90-like isolate: A comparative study. J Fish Dis 2019; 42:1001-1011. [PMID: 30977526 DOI: 10.1111/jfd.13004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 03/11/2019] [Accepted: 03/14/2019] [Indexed: 06/09/2023]
Abstract
Piscirickettsiosis, caused by the intracellular Gram-negative bacteria Piscirickettsia salmonis, is at present the most devastating disease in the Chilean salmon industry. The aim of this study was to analyse disease development after challenge with a P. salmonis strain (EM90-like) under a controlled environment by comparing intraperitoneal challenge with cohabitation challenge. The P. salmonis EM90-like isolate was cultured in a liquid medium for the challenge of 400 Atlantic salmon (Salmo salar) smolts. Cumulative mortality was registered, necropsy was performed, and bacterial distribution in the tissues and histopathological changes were analysed. The results revealed a similar progression of the disease for the two different challenge models. Pathological and histopathological changes became more visible during the development of the clinical phase of the disease. Bacterial DNA was identified in all the analysed tissues indicating a systemic infection. Bacterial tropism to visceral organs was demonstrated by real-time quantitative PCR and immunohistochemistry. Better knowledge of disease development during P. salmonis infection may contribute to further development of challenge models that mimic the field situation during piscirickettsiosis outbreaks. The models can be used to develop and test future preventive measures against the disease.
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Affiliation(s)
- Karla Meza
- VESO Vikan, Namsos, Norway
- Norwegian University of Life Sciences (NMBU), Oslo, Norway
| | | | | | - Ane M Bjelland
- Norwegian University of Life Sciences (NMBU), Oslo, Norway
| | - Henning Sørum
- Norwegian University of Life Sciences (NMBU), Oslo, Norway
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14
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Isla A, Saldarriaga-Córdoba M, Fuentes DE, Albornoz R, Haussmann D, Mancilla-Schulz J, Martínez A, Figueroa J, Avendaño-Herrera R, Yáñez A. Multilocus sequence typing detects new Piscirickettsia salmonis hybrid genogroup in Chilean fish farms: Evidence for genetic diversity and population structure. J Fish Dis 2019; 42:721-737. [PMID: 30851000 DOI: 10.1111/jfd.12976] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 01/15/2019] [Accepted: 01/18/2019] [Indexed: 06/09/2023]
Abstract
Piscirickettsia salmonisis the causative bacterial pathogen of piscirickettsiosis, a salmonid disease that causes notable mortalities in the worldwide aquaculture industry. Published research describes the phenotypic traits, virulence factors, pathogenicity and antibiotic-resistance potential for various P. salmonisstrains. However, evolutionary and genetic information is scarce for P. salmonis. The present study used multilocus sequence typing (MLST) to gain insight into the population structure and evolution of P. salmonis. Forty-two Chilean P. salmonisisolates, as well as the type strain LF-89T , were recovered from diseased Salmo salar, Oncorhynchus kisutchand Oncorhynchus mykissfrom two Chilean Regions. MLST assessed the loci sequences of dnaK, efp, fumC, glyA, murG, rpoD and trpB. Bioinformatics analyses established the genetic diversity among P. salmonis isolates (H = 0.5810). A total of 23 sequence types (ST) were identified, 53.48% of which were represented by ST1, ST5 and ST2. Population structure analysis through polymorphism patterns showed few polymorphic sites (218 nucleotides from 4,010 bp), while dN/dS ratio analysis indicated purifying selection for dnaK, epf, fumC, murG, and rpoD but neutral selection for the trpB loci. The standardized index of association indicated strong linkage disequilibrium, suggesting clonal population structure. However, recombination events were detected in a group of seven isolates. Findings included genogroups homologous to the LF-89T and EM-90 strains, as well as a seven-isolate hybrid genogroup recovered from both assessed regions (three O. mykiss and four S. salar isolates). The presented MLST scheme has comparative potential, with promising applications in studying distinct P. salmonis isolates (e.g., from different hosts, farms, geographical areas) and in understanding the epidemiology of this pathogen.
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Affiliation(s)
- Adolfo Isla
- Facultad de Ciencias, Instituto de Bioquímica y Microbiología, Universidad Austral de Chile, Valdivia, Chile
- Interdisciplinary Center for Aquaculture Research (INCAR), Universidad Andrés Bello, Viña del Mar, Chile
| | - Mónica Saldarriaga-Córdoba
- Centro de Investigación en Recursos Naturales y Sustentabilidad, Universidad Bernardo O'Higgins, Santiago, Chile
| | - Derie E Fuentes
- Fraunhofer Chile Research Foundation, Center for Systems Biotechnology, Santiago, Chile
| | - Romina Albornoz
- Facultad de Ciencias, Instituto de Bioquímica y Microbiología, Universidad Austral de Chile, Valdivia, Chile
| | - Denise Haussmann
- Facultad de Ciencias, Instituto de Bioquímica y Microbiología, Universidad Austral de Chile, Valdivia, Chile
- Interdisciplinary Center for Aquaculture Research (INCAR), Universidad Andrés Bello, Viña del Mar, Chile
- Departamento de Ciencias Básicas, Facultad de Ciencias, Universidad Santo Tomás, Valdivia, Chile
| | | | | | - Jaime Figueroa
- Facultad de Ciencias, Instituto de Bioquímica y Microbiología, Universidad Austral de Chile, Valdivia, Chile
- Interdisciplinary Center for Aquaculture Research (INCAR), Universidad Andrés Bello, Viña del Mar, Chile
| | - Ruben Avendaño-Herrera
- Centro de Investigación en Recursos Naturales y Sustentabilidad, Universidad Bernardo O'Higgins, Santiago, Chile
- Laboratorio de Patología de Organismos Acuáticos y Biotecnología Acuícola, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Viña del Mar, Chile
- Centro de Investigación Marina Quintay (CIMARQ), Universidad Andrés Bello, Quintay, Chile
| | - Alejandro Yáñez
- Facultad de Ciencias, Instituto de Bioquímica y Microbiología, Universidad Austral de Chile, Valdivia, Chile
- Interdisciplinary Center for Aquaculture Research (INCAR), Universidad Andrés Bello, Viña del Mar, Chile
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15
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Gias E, Brosnahan CL, Orr D, Binney B, Ha HJ, Preece MA, Jones B. In vivo growth and genomic characterization of rickettsia-like organisms isolated from farmed Chinook salmon (Oncorhynchus tshawytscha) in New Zealand. J Fish Dis 2018; 41:1235-1245. [PMID: 29806079 DOI: 10.1111/jfd.12817] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 03/26/2018] [Accepted: 04/04/2018] [Indexed: 06/08/2023]
Abstract
A rickettsia-like organism, designated NZ-RLO2, was isolated from Chinook salmon (Oncorhynchus tshawytscha) farmed in the South Island, New Zealand. In vivo growth showed NZ-RLO2 was able to grow in CHSE-214, EPC, BHK-21, C6/36 and Sf21 cell lines, while Piscirickettsia salmonis LF-89T grew in all but BHK-21 and Sf21. NZ-RLO2 grew optimally in EPC at 15°C, CHSE-214 and EPC at 18°C. The growth of LF-89 T was optimal at 15°C, 18°C and 22°C in CHSE-24, but appeared less efficient in EPC cells at all temperatures. Pan-genome comparison of predicted proteomes shows that available Chilean strains of P. salmonis grouped into two clusters (p-value = 94%). NZ-RLO2 was genetically different from previously described NZ-RLO1, and both strains grouped separately from the Chilean strains in one of the two clusters (p-value = 88%), but were closely related to each other. TaqMan and Sybr Green real-time PCR targeting RNA polymerase (rpoB) and DNA primase (dnaG), respectively, were developed to detect NZ-RLO2. This study indicates that the New Zealand strains showed a closer genetic relationship to one of the Chilean P. salmonis clusters; however, more Piscirickettsia genomes from wider geographical regions and diverse hosts are needed to better understand the classification within this genus.
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Affiliation(s)
- E Gias
- Animal Health Laboratory, Ministry for Primary Industries, Upper Hutt, New Zealand
| | - C L Brosnahan
- Animal Health Laboratory, Ministry for Primary Industries, Upper Hutt, New Zealand
| | - D Orr
- Animal Health Laboratory, Ministry for Primary Industries, Upper Hutt, New Zealand
| | - B Binney
- Animal Health Laboratory, Ministry for Primary Industries, Upper Hutt, New Zealand
| | - H J Ha
- Animal Health Laboratory, Ministry for Primary Industries, Upper Hutt, New Zealand
| | - M A Preece
- New Zealand King Salmon, Picton, New Zealand
| | - B Jones
- Animal Health Laboratory, Ministry for Primary Industries, Upper Hutt, New Zealand
- Murdoch University School of Veterinary and Life Sciences, Perth, WA, Australia
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16
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Mancilla M, Saavedra J, Grandón M, Tapia E, Navas E, Grothusen H, Bustos P. The mutagenesis of a type IV secretion system locus of Piscirickettsia salmonis leads to the attenuation of the pathogen in Atlantic salmon, Salmo salar. J Fish Dis 2018; 41:625-634. [PMID: 29251345 DOI: 10.1111/jfd.12762] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 11/06/2017] [Accepted: 11/10/2017] [Indexed: 06/07/2023]
Abstract
Piscirickettsiosis is a threatening infectious disease for the salmon industry, due to it being responsible for significant economic losses. The control of outbreaks also poses considerable environmental challenges. Despite Piscirickettsia salmonis having been discovered as the aetiological agent of the disease more than 25 years ago, its pathogenicity remains poorly understood. Among virulence factors identified so far, type four secretion systems (T4SS) seem to play a key role during the infection caused by the bacterium. We report here the genetic manipulation of P. salmonis by means of the transference of plasmid DNA in mating assays. An insertion cassette was engineered for targeting the icmB gene, which encodes a putative T4SS-ATPase and is carried by one of the chromosomal T4SS clusters found within the genome of P. salmonis PM15972A1, a virulent representative of the EM-90-like strain. The molecular characterization of the resulting mutant strain demonstrated that the insertion interrupted the target gene. Further in vitro testing of the icmB mutant showed a dramatic drop in infectivity as tested in CHSE-214 cells, which is in agreement with its attenuated behaviour observed in vivo. Altogether, our results demonstrate that, similar to other facultative intracellular pathogens, P. salmonis' virulence relies on an intact T4SS.
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Affiliation(s)
- M Mancilla
- Laboratorio de Diagnóstico y Biotecnología, ADL Diagnostic Chile, Puerto Montt, Chile
| | - J Saavedra
- Laboratorio de Diagnóstico y Biotecnología, ADL Diagnostic Chile, Puerto Montt, Chile
| | - M Grandón
- Laboratorio de Diagnóstico y Biotecnología, ADL Diagnostic Chile, Puerto Montt, Chile
| | - E Tapia
- Laboratorio de Diagnóstico y Biotecnología, ADL Diagnostic Chile, Puerto Montt, Chile
| | - E Navas
- Laboratorio de Diagnóstico y Biotecnología, ADL Diagnostic Chile, Puerto Montt, Chile
| | - H Grothusen
- Laboratorio de Diagnóstico y Biotecnología, ADL Diagnostic Chile, Puerto Montt, Chile
| | - P Bustos
- Laboratorio de Diagnóstico y Biotecnología, ADL Diagnostic Chile, Puerto Montt, Chile
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17
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Marshall SH, Flores-Herrera P, Henríquez FA, Gómez FA. Identification and characterization of two variants of the Hfq-sRNA-chaperone in the fish pathogen Piscirickettsia salmonis. J Fish Dis 2018; 41:501-509. [PMID: 29159897 DOI: 10.1111/jfd.12752] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 10/02/2017] [Indexed: 06/07/2023]
Abstract
Small RNA and chaperone proteins form synergistic duos that play pivotal roles in controlling gene expression in bacteria. This is the case for Hfq, a highly pleiotropic pretranslational modulator of general protein expression, which responds to harsh environmental conditions and influences fitness and virulence in a wide range of pathogenic Enterobacteria. Given this relevancy, we evaluated the presence and potential role of Hfq in the fish pathogen Piscirickettsia salmonis, a Gram-negative bacterium that threatens the sustainability of Chilean salmon production. Using bioinformatics tools were identified and characterized two variants of Hfq, which share the consensus RNA-binding domains and the active sites described functional Hfq other bacteria. Additionally, we demonstrated that hfq-1 and hfq-2 were transcriptionally active when growing in cell-free media and in infected susceptible fish cell line. Expression of both genes differed under different growth conditions and under stress, suggesting that their roles might be independent and different, depending on the bacterial physiological status. In conclusion, we demonstrate the existence of two different and functional ORF coding for the hfq marker in marine bacteria and a preliminary analysis indicating that these two novel proteins might have relevant roles in the biology and pathogenic potential of P. salmonis.
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Affiliation(s)
- S H Marshall
- Laboratorio de Genética e Inmunología Molecular, Instituto de Biología, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
| | - P Flores-Herrera
- Laboratorio de Genética e Inmunología Molecular, Instituto de Biología, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
| | - F A Henríquez
- Laboratorio de Genética e Inmunología Molecular, Instituto de Biología, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
| | - F A Gómez
- Laboratorio de Genética e Inmunología Molecular, Instituto de Biología, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
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18
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Rozas-Serri M, Peña A, Arriagada G, Enríquez R, Maldonado L. Comparison of gene expression in post-smolt Atlantic salmon challenged by LF-89-like and EM-90-like Piscirickettsia salmonis isolates reveals differences in the immune response associated with pathogenicity. J Fish Dis 2018; 41:539-552. [PMID: 29143962 DOI: 10.1111/jfd.12756] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 10/14/2017] [Accepted: 10/17/2017] [Indexed: 06/07/2023]
Abstract
Piscirickettsiosis is the main bacterial disease affecting the Chilean salmon farming industry and is responsible for high economic losses. The aim of this study was to describe and comparatively quantify the immune response of post-smolt Atlantic salmon infected by cohabitation with fish bearing LF-89-like and EM-90-like Piscirickettsia salmonis. The expression of 17 genes related to the immune response was studied in head kidney from cohabitant fish by RT-qPCR. Our results at the transcriptomic level suggest that P. salmonis is able to manipulate the kinetics of cytokine production in a way that might constitute a virulence mechanism that promotes intracellular bacterial replication in cells of Atlantic salmon. This strategy involves the creation of an ideal environment for the microorganism based on induction of the inflammatory and IFN-mediated response, modulation of Th1 polarization, reduced antigen processing and presentation, modulation of the evasion of the immune response mediated by CD8+ T cells and promotion of the CD4+ T-cell response during the late stage of infection as a mechanism to escape host defences. This response was significantly exacerbated in fish infected by PS-EM-90 compared with fish infected by PS-LF-89, a finding that is probably associated with the higher pathogenicity of PS-EM-90.
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Affiliation(s)
- M Rozas-Serri
- Pathovet Laboratory Ltd., Puerto Montt, Chile
- Faculty of Veterinary Sciences, Graduate School, Austral University of Chile, Valdivia, Chile
| | - A Peña
- Pathovet Laboratory Ltd., Puerto Montt, Chile
| | - G Arriagada
- EPI-data Research & Consulting, Santiago, Chile
| | - R Enríquez
- Laboratory of Aquatic Pathology and Biotechnology, Faculty of Veterinary Sciences, Animal Pathology Institute, Universidad Austral de Chile, Valdivia, Chile
| | - L Maldonado
- Pathovet Laboratory Ltd., Puerto Montt, Chile
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19
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Parra M, Valenzuela B, Imarai M, Modak B. Obtainment and evaluation of adjuvant effect of the aromatic geranyl derivative Filifolinone in bacterin of Piscirickettsia salmonis. J Fish Dis 2018; 41:157-159. [PMID: 28736920 DOI: 10.1111/jfd.12669] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 05/11/2017] [Accepted: 05/15/2017] [Indexed: 06/07/2023]
Affiliation(s)
- M Parra
- Laboratory of Natural Products Chemistry, Centre of Aquatic Biotechnology, Department of Environmental Sciences, Faculty of Chemistry and Biology, University of Santiago of Chile, Santiago, Chile
| | - B Valenzuela
- Laboratory of Natural Products Chemistry, Centre of Aquatic Biotechnology, Department of Environmental Sciences, Faculty of Chemistry and Biology, University of Santiago of Chile, Santiago, Chile
| | - M Imarai
- Laboratory of Immunology, Centre of Aquatic Biotechnology, Department of Biology, Faculty of Chemistry and Biology, University of Santiago of Chile, Santiago, Chile
| | - B Modak
- Laboratory of Natural Products Chemistry, Centre of Aquatic Biotechnology, Department of Environmental Sciences, Faculty of Chemistry and Biology, University of Santiago of Chile, Santiago, Chile
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20
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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.). J Fish Dis 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] [What about the content of this article? (0)] [Affiliation(s)] [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.
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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
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21
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Lagos F, Cartes C, Vera T, Haussmann D, Figueroa J. Identification of genomic islands in Chilean Piscirickettsia salmonis strains and analysis of gene expression involved in virulence. J Fish Dis 2017; 40:1321-1331. [PMID: 28150307 DOI: 10.1111/jfd.12604] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 11/23/2016] [Accepted: 11/27/2016] [Indexed: 06/06/2023]
Abstract
Piscirickettsia salmonis, an agent of Piscirickettsiosis, is the cause of major losses in the Chilean salmon industry. We identified, characterized and bioinformatically analysed genomic islands in field strains of P. Salmonis, using the bioinformatic software PIPS, that uses the characteristics of the islands of pathogenicity to identify them. We analysed nine partially sequenced genomes in different new field strains, and compared them with the LF-89 (Type strain) genome, selecting a genomic island present in all of them. We then evaluated the relative expression of three genes present in that island. From the obtained results, we conclude that the expression of the tcf gene is directly proportional to the cytopathogenicity in vitro of the bacteria; the product of the dnsa gene could contribute to its pathogenicity, but would be potentiated by one or more factors. The product of the gene liso is necessary for the virulence process and could have functions in early stages of infection. Regarding the strains, the IBM-040 strain showed a significant increase in the expression of all the genes in the study. Contrarily, LF-89 only presented a significant increase in expression of the gene liso, which correlates with the cytopathogenicity in vitro observed in the SHK-1 cells.
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Affiliation(s)
- F Lagos
- Centro FONDAP: Interdisciplinary Center for Aquaculture Research (INCAR), Concepción, Chile
| | - C Cartes
- Facultad de Ciencias, Instituto de Bioquímica y Microbiología, Universidad Austral de Chile, Valdivia, Chile
| | - T Vera
- Facultad de Ciencias, Instituto de Bioquímica y Microbiología, Universidad Austral de Chile, Valdivia, Chile
| | - D Haussmann
- Centro FONDAP: Interdisciplinary Center for Aquaculture Research (INCAR), Concepción, Chile
- Facultad de Ciencias, Instituto de Bioquímica y Microbiología, Universidad Austral de Chile, Valdivia, Chile
- Departmento de Ciencias Básicas, Facultad de Ciencias, Universidad Santo Tomás, Valdivia, Chile
| | - J Figueroa
- Centro FONDAP: Interdisciplinary Center for Aquaculture Research (INCAR), Concepción, Chile
- Facultad de Ciencias, Instituto de Bioquímica y Microbiología, Universidad Austral de Chile, Valdivia, Chile
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22
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Rozas-Serri M, Ildefonso R, Peña A, Enríquez R, Barrientos S, Maldonado L. Comparative pathogenesis of piscirickettsiosis in Atlantic salmon (Salmo salar L.) post-smolt experimentally challenged with LF-89-like and EM-90-like Piscirickettsia salmonis isolates. J Fish Dis 2017; 40:1451-1472. [PMID: 28745821 DOI: 10.1111/jfd.12671] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 05/23/2017] [Accepted: 05/24/2017] [Indexed: 05/20/2023]
Abstract
Piscirickettsiosis (SRS) is the most prevalent bacterial disease in Chilean salmon aquaculture and is responsible for high economic losses. The aim of this study was to comparatively characterize the pathogenesis of SRS in post-smolt Atlantic salmon during the early and late stages of infection with Piscirickettsia salmonis LF-89-like (PS-LF-89) and EM-90-like (PS-EM-90) using a cohabitation challenge. The pathogenesis of cohabitant fish infected with the two isolates was relatively different due to cohabitant fish infected with PS-EM-90 showing higher cumulative mortality and shorter time until death compared with PS-LF-89 fish. PS-LF-89 caused an SRS infection characterized by kidney and liver lesions, whereas PS-EM-90 caused systemic and haemorrhagic disease characterized by kidney, liver, heart, brain, skeletal muscle and intestine lesions. Decreased serum concentration of total proteins and albumin as well as increased serum ALT, AST and creatinine levels in fish infected with both isolates confirmed that changes in liver and kidney function occurred during infection. Tissue damage, expressed as an SRS histoscore, showed a strong positive correlation with the bacterial load expressed as abundance of P. salmonis 16S rRNA transcripts in the livers and kidneys of fish affected with either isolate, but the correlation was significantly higher in fish infected with PS-EM-90. The results contribute to improving the understanding of the bacteria-host interaction.
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Affiliation(s)
- M Rozas-Serri
- Pathovet Laboratory Ltd., Puerto Montt, Chile
- Faculty of Veterinary Sciences, Graduate School, Universidad Austral de Chile, Valdivia, Chile
| | - R Ildefonso
- Pathovet Laboratory Ltd., Puerto Montt, Chile
| | - A Peña
- Pathovet Laboratory Ltd., Puerto Montt, Chile
| | - R Enríquez
- Laboratory of Aquatic Pathology and Biotechnology, Faculty of Veterinary Sciences, Animal Pathology Institute, Universidad Austral de Chile, Valdivia, Chile
| | | | - L Maldonado
- Pathovet Laboratory Ltd., Puerto Montt, Chile
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23
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Saavedra J, Hernandez N, Osses A, Castillo A, Cancino A, Grothusen H, Navas E, Henriquez P, Bohle H, Bustamante F, Bustos P, Mancilla M. Prevalence, geographic distribution and phenotypic differences of Piscirickettsia salmonis EM-90-like isolates. J Fish Dis 2017. [PMID: 28075013 DOI: 10.1016/s0044-8486(00)00315-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Early reports accounted for two main genotypes of Piscirickettsia salmonis, a fish pathogen and causative agent of piscirickettsiosis, placing the single isolate EM-90 apart from the prototypic LF-89 and related isolates. In this study, we provide evidence that, contrary to what has been supposed, the EM-90-like isolates are highly prevalent and disseminated across Chilean marine farms. Molecular analysis of 507 P. salmonis field isolates derived from main rearing areas, diverse hosts and collected over 6 years, revealed that nearly 50% of the entire collection were indeed typed as EM-90-like. Interestingly, these isolates showed a marked host preference, being recovered exclusively from Atlantic salmon (Salmo salar) samples. Although both strains produce undistinguishable pathological outcomes, differences regarding growth kinetics and susceptibility to the antibiotics and bactericidal action of serum could be identified. In sum, our results allow to conclude that the EM-90-like isolates represent an epidemiologically relevant group in the current situation of piscirickettsiosis. Based on the consistency between genotype and phenotype exhibited by this strain, we point out the need for genotypic studies that may be as important for the Chilean salmon industry as the continuous surveillance of antimicrobial susceptibility patterns.
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Affiliation(s)
- J Saavedra
- Laboratorio de Diagnóstico y Biotecnología, ADL Diagnostic Chile Ltda, Puerto Montt, Chile
| | - N Hernandez
- Laboratorio de Diagnóstico y Biotecnología, ADL Diagnostic Chile Ltda, Puerto Montt, Chile
| | - A Osses
- Laboratorio de Diagnóstico y Biotecnología, ADL Diagnostic Chile Ltda, Puerto Montt, Chile
| | - A Castillo
- Laboratorio de Diagnóstico y Biotecnología, ADL Diagnostic Chile Ltda, Puerto Montt, Chile
| | - A Cancino
- Laboratorio de Diagnóstico y Biotecnología, ADL Diagnostic Chile Ltda, Puerto Montt, Chile
| | - H Grothusen
- Laboratorio de Diagnóstico y Biotecnología, ADL Diagnostic Chile Ltda, Puerto Montt, Chile
| | - E Navas
- Laboratorio de Diagnóstico y Biotecnología, ADL Diagnostic Chile Ltda, Puerto Montt, Chile
| | - P Henriquez
- Laboratorio de Diagnóstico y Biotecnología, ADL Diagnostic Chile Ltda, Puerto Montt, Chile
| | - H Bohle
- Laboratorio de Diagnóstico y Biotecnología, ADL Diagnostic Chile Ltda, Puerto Montt, Chile
| | - F Bustamante
- Laboratorio de Diagnóstico y Biotecnología, ADL Diagnostic Chile Ltda, Puerto Montt, Chile
| | - P Bustos
- Laboratorio de Diagnóstico y Biotecnología, ADL Diagnostic Chile Ltda, Puerto Montt, Chile
| | - M Mancilla
- Laboratorio de Diagnóstico y Biotecnología, ADL Diagnostic Chile Ltda, Puerto Montt, Chile
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24
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Saavedra J, Hernandez N, Osses A, Castillo A, Cancino A, Grothusen H, Navas E, Henriquez P, Bohle H, Bustamante F, Bustos P, Mancilla M. Prevalence, geographic distribution and phenotypic differences of Piscirickettsia salmonis EM-90-like isolates. J Fish Dis 2017; 40:1055-1063. [PMID: 28075013 DOI: 10.1111/jfd.12581] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 10/12/2016] [Accepted: 10/13/2016] [Indexed: 06/06/2023]
Abstract
Early reports accounted for two main genotypes of Piscirickettsia salmonis, a fish pathogen and causative agent of piscirickettsiosis, placing the single isolate EM-90 apart from the prototypic LF-89 and related isolates. In this study, we provide evidence that, contrary to what has been supposed, the EM-90-like isolates are highly prevalent and disseminated across Chilean marine farms. Molecular analysis of 507 P. salmonis field isolates derived from main rearing areas, diverse hosts and collected over 6 years, revealed that nearly 50% of the entire collection were indeed typed as EM-90-like. Interestingly, these isolates showed a marked host preference, being recovered exclusively from Atlantic salmon (Salmo salar) samples. Although both strains produce undistinguishable pathological outcomes, differences regarding growth kinetics and susceptibility to the antibiotics and bactericidal action of serum could be identified. In sum, our results allow to conclude that the EM-90-like isolates represent an epidemiologically relevant group in the current situation of piscirickettsiosis. Based on the consistency between genotype and phenotype exhibited by this strain, we point out the need for genotypic studies that may be as important for the Chilean salmon industry as the continuous surveillance of antimicrobial susceptibility patterns.
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Affiliation(s)
- J Saavedra
- Laboratorio de Diagnóstico y Biotecnología, ADL Diagnostic Chile Ltda, Puerto Montt, Chile
| | - N Hernandez
- Laboratorio de Diagnóstico y Biotecnología, ADL Diagnostic Chile Ltda, Puerto Montt, Chile
| | - A Osses
- Laboratorio de Diagnóstico y Biotecnología, ADL Diagnostic Chile Ltda, Puerto Montt, Chile
| | - A Castillo
- Laboratorio de Diagnóstico y Biotecnología, ADL Diagnostic Chile Ltda, Puerto Montt, Chile
| | - A Cancino
- Laboratorio de Diagnóstico y Biotecnología, ADL Diagnostic Chile Ltda, Puerto Montt, Chile
| | - H Grothusen
- Laboratorio de Diagnóstico y Biotecnología, ADL Diagnostic Chile Ltda, Puerto Montt, Chile
| | - E Navas
- Laboratorio de Diagnóstico y Biotecnología, ADL Diagnostic Chile Ltda, Puerto Montt, Chile
| | - P Henriquez
- Laboratorio de Diagnóstico y Biotecnología, ADL Diagnostic Chile Ltda, Puerto Montt, Chile
| | - H Bohle
- Laboratorio de Diagnóstico y Biotecnología, ADL Diagnostic Chile Ltda, Puerto Montt, Chile
| | - F Bustamante
- Laboratorio de Diagnóstico y Biotecnología, ADL Diagnostic Chile Ltda, Puerto Montt, Chile
| | - P Bustos
- Laboratorio de Diagnóstico y Biotecnología, ADL Diagnostic Chile Ltda, Puerto Montt, Chile
| | - M Mancilla
- Laboratorio de Diagnóstico y Biotecnología, ADL Diagnostic Chile Ltda, Puerto Montt, Chile
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