Inter-Laboratory Comparison of qPCR Assays for Piscirickettsia salmonis in Atlantic Salmon (Salmo salar L.) in 11 Chilean Laboratories.

Real-time PCR (qPCR) testing is an essential component of early detection surveillance systems for Piscirickettsia salmonis infection in Atlantic salmon farms in Chile. Currently, all 11 laboratories in the authorised diagnostic laboratory network use assays based on published protocols. Compared with other P.

Current vaccination strategy against Piscirickettsia salmonis in Chile based only on the EM-90 genogroup shows incomplete cross-protection for the LF-89 genogroup.

Piscirickettsia salmonis, the primary bacterial disease in Chilean salmon farming, necessitates a constant refinement of control strategies. This study hypothesized that the current vaccination strategy for SRS control in the Chilean Atlantic salmon aquaculture industry, which has been in place since 2017 (ALPHA JECT® 5.1 plus LiVac®), solely relies on vaccines formulated with the EM-90 genogroup of P.

First Report of as an Emerging Bacterial Pathogen of Farmed Nile Tilapia () in Brazil.

Brazil is one of the world's leading producers of Nile tilapia, . However, the industry faces a major challenge in terms of infectious diseases, as at least five new pathogens have been formally described in the last five years. species are Gram-negative anaerobic bacteria that are often described as fish pathogens causing Motile Aeromonas Septicemia (MAS).

Co-Infection by LF-89-Like and EM-90-Like Genogroups of in Farmed Atlantic Salmon in Chile: Implications for Surveillance and Control of Piscirickettsiosis.

Piscirickettsiosis (SRS), caused by , is the main infectious disease that affects farmed Atlantic salmon in Chile. Currently, the official surveillance and control plan for SRS in Chile is based only on the detection of , but neither of its genogroups (LF-89-like and EM-90-like) are included. Surveillance at the genogroup level is essential not only for defining and evaluating the vaccination strategy against SRS, but it is also of utmost importance for early diagnosis, clinical prognosis in the field, treatment, and control of the disease.

Reference Intervals for Blood Biomarkers in Farmed Atlantic Salmon, Coho Salmon and Rainbow Trout in Chile: Promoting a Preventive Approach in Aquamedicine.

The mission of veterinary clinical pathology is to support the diagnostic process by using tests to measure different blood biomarkers to support decision making about farmed fish health and welfare. The objective of this study is to provide reference intervals (RIs) for 44 key hematological, blood biochemistry, blood gasometry and hormones biomarkers for the three most economically important farmed salmonid species in Chile (Atlantic salmon, coho salmon and rainbow trout) during the freshwater (presmolt and smolt age range) and seawater stages (post-smolt and adult age range). Our results confirmed that the concentration or activity of most blood biomarkers depend on the salmonid species, age range and/or the interaction between them, and they are often biologically related to each other.

Why Does Break the Immunological Paradigm in Farmed Salmon? Biological Context to Understand the Relative Control of Piscirickettsiosis.

Piscirickettsiosis (SRS) has been the most important infectious disease in Chilean salmon farming since the 1980s. It was one of the first to be described, and to date, it continues to be the main infectious cause of mortality. How can we better understand the epidemiological situation of SRS? The catch-all answer is that the Chilean salmon farming industry must fight year after year against a multifactorial disease, and apparently only the environment in Chile seems to favor the presence and persistence of .

Full recombinant flagellin B from Vibrio anguillarum (rFLA) and its recombinant D1 domain (rND1) promote a pro-inflammatory state and improve vaccination against P. salmonis in Atlantic salmon (S. salar).

Flagellin is the major component of the flagellum, and a ligand for Toll-like receptor 5. As reported, recombinant flagellin (rFLA) from Vibrio anguillarum and its D1 domain (rND1) are able to promote in vitro an upregulation of pro-inflammatory genes in gilthead seabream (Sparus aurata) and rainbow trout (Oncorhynchus mykiss) macrophages. This study evaluated the in vitro and in vivo stimulatory/adjuvant effect for rFLA and rND1 during P.

Cost-effectiveness of longitudinal surveillance for Piscirickettsia salmonis using qPCR in Atlantic salmon farms (Salmo salar) in Chile.

Costs of diagnostic testing including sample collection, sampling frequency and sample size are an important consideration in the evaluation of the economic feasibility of alternative surveillance strategies for detection of infectious diseases in aquatic animals. In Chile, Piscirickettsia salmonis is the primary reason for antibiotic treatments in farmed Atlantic salmon. In 2012, a surveillance and control programme for piscirickettsiosis was established with an overall goal of reducing antibiotic use.

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.

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).

Atlantic Salmon Pre-smolt Survivors of Infection Show Inhibited Cell-Mediated Adaptive Immune Response and a Higher Risk of Death During the Late Stage of Infection at Lower Water Temperatures.

Bacterial kidney disease (BKD) is widespread in many areas of the world and can cause substantial economic losses for the salmon aquaculture industry. The objective of this study was to investigate the pathophysiological response and gene expression profiles related to the immune response at different water temperatures and to identify the best immunopathological biomarkers to define a phenotype of resistance to BKD. The abundance of transcripts of in the head kidney was significantly higher in infected fish at 11°C.

Gene expression associated with immune response in Atlantic salmon head-kidney vaccinated with inactivated whole-cell bacterin of Piscirickettsia salmonis and pathogenic isolates.

Piscirickettsiosis is the most challenging disease present in the Chilean salmon industry. The aim of this study was to describe the expression of genes associated with immune response of Atlantic salmon intraperitoneally infected with LF-89 and EM-90 Piscirickettsia salmonis and vaccinated with inactivated whole-cell bacterin of P. salmonis.

Transcriptomic profiles of post-smolt Atlantic salmon challenged with Piscirickettsia salmonis reveal a strategy to evade the adaptive immune response and modify cell-autonomous immunity.

Piscirickettsiosis is the main bacterial disease affecting the Chilean salmon farming industry and is responsible for high economic losses. The development of effective strategies to control piscirickettsiosis has been limited in part by insufficient knowledge of the host response. The aim of this study was to use RNA sequencing to describe the transcriptional profiles of the responses of post-smolt Atlantic salmon infected with LF-89-like or EM-90-like Piscirickettsia salmonis.