Article
Fisheries
Cristian Oliver, Constanza Cespedes, Natacha Santibanez, Pamela Ruiz, Alex Romero
Summary: Improper use of antibiotics in the Chilean aquaculture industry leads to the generation of multidrug resistance bacteria, which form biofilms and serve as reservoirs of pathogens in the marine environment.
JOURNAL OF FISH DISEASES
(2023)
Article
Microbiology
Javiera Ortiz-Severin, Camila J. Stuardo, Natalia E. Jimenez, Ricardo Palma, Maria P. Cortes, Jonathan Maldonado, Alejandro Maass, Veronica Cambiazo
Summary: The research found that nutrient scarcity plays a role in bacterial antibiotic resistance, with P. salmonis showing resistance to multiple antibiotics under nutrient-limited conditions. The concentration of antibiotics in a defined medium affects their inhibitory effects on the pathogen.
FRONTIERS IN MICROBIOLOGY
(2021)
Editorial Material
Fisheries
Felipe C. Cabello, Henry P. Godfrey
Summary: Recent information from Chile indicates that the apparent high virulence of Piscirickettsia salmonis in cultured salmonids is due to the stress caused by the unhealthy high concentrations at which the fish are grown during production, rather than any inherently greater virulence of this opportunistic pathogen. These high disease levels result in excessive use of antimicrobials, which in turn negatively affect both piscine and human health, as well as the environment.
Article
Microbiology
Marco Rozas-Serri, Andrea Pena, Ian Gardner, Estefania Penaloza, Lucerina Maldonado, Ariel Munoz, Fernando O. Mardones, Catalina Rodriguez, Ricardo Ildefonso, Carolina Senn, Felipe Aranis
Summary: Piscirickettsiosis (SRS), caused by Piscirickettsia salmonis, is the main infectious disease affecting farmed Atlantic salmon in Chile. The official surveillance and control plan for SRS in Chile currently only detects P. salmonis without distinguishing between its LF-89-like and EM-90-like genogroups. Monitoring at the genogroup level is essential for vaccination strategy, early diagnosis, prognosis, treatment, and control of the disease.
Article
Biotechnology & Applied Microbiology
Robert Mukiibi, Carolina Penaloza, Alejandro Gutierrez, Jose M. Yanez, Ross D. Houston, Diego Robledo
Summary: This study investigated DNA methylation changes in response to P. salmonis infection in the head kidney and liver tissue of Atlantic salmon, and the interaction between gene expression and DNA methylation in the same tissues. The results suggest that methylation plays an important role in gene expression regulation and response to infectious diseases, providing valuable insights for utilizing epigenetic markers to improve disease resistance and manage fish health in salmon aquaculture.
Article
Immunology
Gabriela Carril, Hanne C. Winther-Larsen, Marie Lovoll, Henning Sorum
Summary: This study evaluated the effects of co-cultivation of P. salmonis genogroups on bacterial growth performance and virulence factor expression in Atlantic salmon. It was found that co-cultivation can modulate their behavior and virulence effector expression.
FRONTIERS IN CELLULAR AND INFECTION MICROBIOLOGY
(2023)
Article
Immunology
Xi Xue, Albert Caballero-Solares, Jennifer R. Hall, Navaneethaiyer Umasuthan, Surendra Kumar, Eva Jakob, Stanko Skugor, Christopher Hawes, Javier Santander, Richard G. Taylor, Matthew L. Rise
Summary: Salmonid rickettsial septicemia (SRS) caused by Piscirickettsia salmonis is a severe disease in salmonids. This study investigated the transcriptomic responses of Atlantic salmon to an EM-90-like isolate, identifying two infection phenotypes and a variety of immune processes. The study broadened the understanding of molecular pathways underlying P. salmonis-triggered responses in Atlantic salmon and identified potential biomarkers for diagnosis and treatment.
FRONTIERS IN IMMUNOLOGY
(2021)
Article
Immunology
Juan Pablo Pontigo, Carla Espinoza, Mauricio Hernandez, Guillermo Nourdin, Cristian Oliver, Ruben Avendano-Herrera, Jaime Figueroa, Cecilia Rauch, Jose M. Troncoso, Luis Vargas-Chacoff, Alejandro J. Yanez
Summary: Developing an effective and economical vaccine against Piscirickettsia salmonis is crucial for sustainable salmon farming. One vaccine prototype effectively protected Atlantic salmon by inducing specific antibodies and pro-inflammatory cytokines, while the other two activated innate immune responses but did not provide protection. Understanding the protein formulation of vaccines based on P. salmonis is essential for improving immune responses and disease resistance in Atlantic salmon.
FRONTIERS IN IMMUNOLOGY
(2021)
Article
Immunology
Danixa Martinez, Ricardo Oyarzun-Salazar, Ana Maria Quilapi, Jose Coronado, Ricardo Enriquez, Carolina Vargas-Lagos, Cristian Oliver, Natacha Santibanez, Marcos Godoy, Jose Luis Munoz, Luis Vargas-Chacoff, Alex Romero
Summary: This study evaluated the activation of nutritional immunity in Atlantic salmon stimulated with live and inactivated Piscirickettsia salmonis. The results showed that both live and inactivated P. salmonis could activate nutritional immunity, and there was no distinction between the two. Genetic material of P. salmonis was detected in the liver tissue of the fish. The hematocrit percentage decreased in fish stimulated with live P. salmonis, while it remained unchanged in fish stimulated with inactivated P. salmonis. Plasma iron content decreased in both experimental groups, but the decrease was statistically significant only at 3 dpi. Immune-nutritional markers were modulated in both experimental conditions, while other markers were down-regulated. Intracellular iron content increased in the liver at 7 and 14 dpi, while zinc content decreased at 14 dpi in both experimental groups. However, manganese content was not altered by the stimulation. These findings suggest that nutritional immunity responds similarly to live and inactivated P. salmonis, and may be self-activated by the detection of PAMPs rather than a sequestration and/or competition of micronutrients by the living microorganism.
FRONTIERS IN IMMUNOLOGY
(2023)
Article
Ecology
Isabel Schober, Boyke Bunk, Gabriela Carril, Heike M. Freese, Nicolas Ojeda, Thomas Riedel, Jan P. Meier-Kolthoff, Markus Goeker, Cathrin Sproeer, Patricio A. Flores-Herrera, Guillermo Nourdin-Galindo, Fernando Gomez, Constanza Cardenas, Felipe Vasquez-Ponce, Alvaro Labra, Jaime Figueroa, Jorge Olivares-Pacheco, Ulrich Nuebel, Johannes Sikorski, Sergio H. Marshall, Jorg Overmann
Summary: The study reveals the global diversity, evolution, and selection of Piscirickettsia salmonis, an important bacterial pathogen in aquaculture. The research shows that P. salmonis consists of distinct genetically isolated species and highlights the role of transposases in its diversification. Group-specific genes may contribute to differences in virulence between strains, but horizontal acquisition of resistance genes does not explain the failure of antibiotic treatment in outbreaks.
Editorial Material
Fisheries
Felipe C. Cabello, Henry P. Godfrey
Summary: Dr. Avendano-Herrera's comments on our review are mostly marginal and do not weaken our hypothesis. We believe that infections caused by P. salmonis can be prevented by improving husbandry practices, and that excessive use of antimicrobials is detrimental to health.
Article
Microbiology
Adolfo Isla, J. Eduardo Martinez-Hernandez, Hector A. Levipan, Denise Haussmann, Jaime Figueroa, Maria Cecilia Rauch, Vinicius Maracaja-Coutinho, Alejandro Yanez
Summary: The development of a multiplex PCR for genotyping LF-89 and EM-90 genogroups of P. salmonis based on comparative genomics of 73 fully sequenced genomes revealed shared coding sequences among all tested genomes, as well as unique sequences for LF-89 and EM-90 genogroups. This method proved to be a reliable and rapid alternative to classical sequencing and analyzing polymorphisms in field samples infected with LF-89 or EM-90 strains.
FRONTIERS IN MICROBIOLOGY
(2021)
Article
Fisheries
Juan Pablo Pontigo, Alejandro Yanez, Patricio Sanchez, Luis Vargas-Chacoff
Summary: This study analyzed six mRNA variants of NLRC3 in Atlantic salmon, identifying one variant that was over-expressed during early infection stages. Alterations in the amino acid sequence of one isoform were found to directly impact pathogen recognition function.
DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY
(2021)
Article
Biology
Carolina Figueroa, Debora Torrealba, Byron Morales-Lange, Luis Mercado, Brian Dixon, Pablo Conejeros, Gabriela Silva, Carlos Soto, Jose A. Gallardo
Summary: This study evaluated the effectiveness of two commercial vaccines against two prevalent genetic variants of Piscirickettsia salmonis. The vaccines were found to be ineffective in providing protection. Further research is needed to explore the impact of pathogen heterogeneity on vaccine efficacy.
Review
Gastroenterology & Hepatology
Javier Fernandez, Salvatore Piano, Michele Bartoletti, Emmanuel Q. Wey
Summary: Bacterial infections are common in cirrhotic patients with acute decompensation or acute-on-chronic liver failure, while fungal infections are less common but associated with high short-term mortality. Early diagnosis and appropriate empirical treatment are crucial in managing these patients. Combatting antibiotic resistance and adopting more complex treatment strategies are essential in the current management of cirrhotic patients.
JOURNAL OF HEPATOLOGY
(2021)
Article
Fisheries
P. Henriquez, M. Kaiser, H. Bohle, P. Bustos, M. Mancilla
JOURNAL OF FISH DISEASES
(2016)
Article
Immunology
Marcos Mancilla
FRONTIERS IN CELLULAR AND INFECTION MICROBIOLOGY
(2016)
Article
Fisheries
M. Mancilla, J. Saavedra, M. Grandon, E. Tapia, E. Navas, H. Grothusen, P. Bustos
JOURNAL OF FISH DISEASES
(2018)
Article
Immunology
Guillermo Nourdin-Galindo, Patricio Sanchez, Cristian F. Molina, Daniela A. Espinoza-Rojas, Cristian Oliver, Pamela Ruiz, Luis Vargas-Chacoff, Juan G. Carcamo, Jaime E. Figueroa, Marcos Mancilla, Vinicius Maracaja-Coutinho, Alejandro J. Yanez
FRONTIERS IN CELLULAR AND INFECTION MICROBIOLOGY
(2017)
Article
Microbiology
Jose Saavedra, Maritza Grandon, Juan Villalobos-Gonzalez, Harry Bohle, Patricio Bustos, Marcos Mancilla
FRONTIERS IN MICROBIOLOGY
(2018)
Editorial Material
Microbiology
Marcos Mancilla
FRONTIERS IN MICROBIOLOGY
(2018)
Article
Fisheries
P. Henriquez, H. Bohle, F. Bustamante, P. Bustos, M. Mancilla
JOURNAL OF FISH DISEASES
(2015)
Article
Fisheries
Maritza Grandon, Rute Irgang, Jose Saavedra, Marcos Mancilla, Ruben Avendano-Herrera
Summary: Surveillance of antibiotic resistance in fish pathogens is crucial, particularly for Renibacterium salmoninarum in salmon farming. A study in southern Chile revealed an evolving subpopulation of non-wild-type isolates for erythromycin, while isolates were most susceptible to florfenicol and oxytetracycline. This information can be useful for antibiotic surveillance programs and future revisions in MIC values determination methods.
JOURNAL OF FISH DISEASES
(2021)
Article
Fisheries
Rute Irgang, Marcos Mancilla, Ruben Avendano-Herrera
JOURNAL OF FISH DISEASES
(2021)
Review
Fisheries
Ruben Avendano-Herrera, Marcos Mancilla, Claudio D. Miranda
Summary: Chile, the second largest producer of salmon, is facing concerns over the intensive use of antimicrobials in its salmon farming industry. This review provides a comprehensive analysis of the historical and current use of antimicrobials in Chilean salmonid farming, as well as the impacts on the environment and antibiotic resistance. It aims to clarify outdated or poorly supported information in existing literature and offers recommendations for reducing antimicrobial use and controlling bacterial fish pathogens.
REVIEWS IN AQUACULTURE
(2022)
Article
Microbiology
Harry Bohle, Patricio Henriquez, Horst Grothusen, Esteban Navas, Fernando Bustamante, Patricio Bustos, Marcos Mancilla
GENOME ANNOUNCEMENTS
(2017)
Article
Microbiology
Harry Bohle, Patricio Henriquez, Horst Grothusen, Esteban Navas, Alvaro Sandoval, Fernando Bustamante, Patricio Bustos, Marcos Mancilla
GENOME ANNOUNCEMENTS
(2014)
Article
Harry Bohle, Patricio Bustos, Laura Leiva, Horst Grothusen, Esteban Navas, Alvaro Sandoval, Fernando Bustamante, Karen Montecinos, Alvaro Gaete, Marcos Mancilla
GENOME ANNOUNCEMENTS
(2018)
Article
Horst Grothusen, Alejandro Castillo, Patricio Henriquez, Esteban Navas, Harry Bohle, Carolina Araya, Fernando Bustamante, Patricio Bustos, Marcos Mancilla
GENOME ANNOUNCEMENTS
(2016)