Publications by authors named "Felipe Reyes-Lopez"

Salmonid rickettsial septicemia (SRS), caused by , has been the most severe health concern for the Chilean salmon industry. The efforts to control infections have focused on using antibiotics and vaccines. However, infected salmonids exhibit limited responses to the treatments.

View Article and Find Full Text PDF

The skin of bony fish is the first physical barrier and is responsible for maintaining the integrity of the fish. Lesions make the skin vulnerable to potential infection by pathogens present in the aquatic environment. In this way, wound repair has barely been studied in gilthead sea bream.

View Article and Find Full Text PDF

Background: As the COVID-19 pandemic persists, infections continue to surge globally. Presently, the most effective strategies to curb the disease and prevent outbreaks involve fostering immunity, promptly identifying positive cases, and ensuring their timely isolation. Notably, there are instances where the SARS-CoV-2 virus remains infectious even after patients have completed their quarantine.

View Article and Find Full Text PDF

is the most important health problem facing Chilean Aquaculture. Previous reports suggest that can survive in salmonid macrophages by interfering with the host immune response. However, the relevant aspects of the molecular pathogenesis of have been poorly characterized.

View Article and Find Full Text PDF

The present study explores the effects of two supplementation levels of (1.1% and 2.2%) as a probiotic in a reference low fish meal-based diet on the skin mucosal tissue in .

View Article and Find Full Text PDF
Article Synopsis
  • The evolution of SARS-CoV-2 variants, particularly the Omicron variant, poses a substantial danger by potentially undermining immunity from vaccinations and previous infections, leading to increased reinfections and localized outbreaks in regions like Chile.
  • A study analyzing 578,670 COVID-19 tests from April 2020 to July 2022 found that the highest rates of reinfection in Chile occurred during the fourth and fifth waves, with an average gap of 372 days between infections.
  • Despite a significant vaccination rate, the results indicate that the Omicron variant is highly effective at evading immune responses, emphasizing the need for informed public health strategies to address these challenges.
View Article and Find Full Text PDF

Background: The development of a sustainable business model with social acceptance, makes necessary to develop new strategies to guarantee the growth, health, and well-being of farmed animals. Debaryomyces hansenii is a yeast species that can be used as a probiotic in aquaculture due to its capacity to i) promote cell proliferation and differentiation, ii) have immunostimulatory effects, iii) modulate gut microbiota, and/or iv) enhance the digestive function. To provide inside into the effects of D.

View Article and Find Full Text PDF

In this study, we investigated the effects of the artificial photoperiods that mimic summer (16L:8D; 16 h Light: 8 h Dark) and winter (8L:16D) solstices, equinoxes (12L:12D), and the artificial 24-h light regimen (24L:0D) on the leukocyte populations and the T helper and regulatory type responses on rainbow trout (Oncorhynchus mykiss). Using flow cytometry analysis, we found that photoperiod induces changes in head kidney leukocyte subsets. The lymphoid subset increased in the 16L:8D summer solstice regime.

View Article and Find Full Text PDF

The coordinated migration of immune cells from lymphoid organs to in or out of the bloodstream, and towards the site of infection or tissue damage is fundamental for an efficient innate and adaptive immune response. Interestingly, an essential part of this movement is mediated by chemoattractant cytokines called chemokines. Although the nature and function of chemokines and their receptors are well documented in mammals, much research is needed to accomplish a similar level of understanding of the role of chemokines in fish immunity.

View Article and Find Full Text PDF

The COVID-19 pandemic continues to affect several countries. One of the best ways to control its spread is the timely identification of infected patients for isolation and quarantine. While an episode of infection lasts an average of 8-10 days from the onset of symptoms, there is literature describing long-lasting viral persistence events.

View Article and Find Full Text PDF

Introduction: The COVID-19 pandemic is still in force, causing global public health challenges and threats. Although vaccination and herd immunity have proven to be the most efficient way to control the pandemic, massive and early testing of patients using the RT-qPCR technique is crucial for constant genomic surveillance. The appearance of variants of SARS-CoV-2 with new mutations can reduce the efficiency of diagnostic detection.

View Article and Find Full Text PDF

Blood by-products are an untapped source of high-quality ingredients for aquafeeds, containing a broad variety of cytokines, hormones, growth factors, proteins, bioactive peptides, and amino acids. The effects of the spray-dried porcine plasma (SDPP), a type of processed animal protein on several immune parameters, were evaluated in sea bream using ex vivo and in vitro assays. In this study, fish were fed with two isoproteic, isolipidic, and isoenergetic diets: control diet (7% fish meal, FM) and SDPP diet (2% FM and 5% SDPP).

View Article and Find Full Text PDF

The variant of concern (VOC) SARS-CoV-2 Omicron (B.1.1529) has been described as a highly contagious variant but less virulent than the current variant being monitored (VBM) Delta (B.

View Article and Find Full Text PDF

The COVID-19 pandemic continues to be a concern and keeps global health authorities on alert. The RT-PCR technique has been the gold-standard assay for detecting the SARS-CoV-2 virus. However, rapid antigen tests (RATs) have been widely used to increase the number of tests faster and more efficiently in the population.

View Article and Find Full Text PDF

CD8+ and CD4+ T-cells play a key role in cellular immune responses against cancer by cytotoxic responses and effector lineages differentiation, respectively. These subsets have been found in different types of cancer; however, it is unclear whether tumor-infiltrating T-cell subsets exhibit similar transcriptome profiling across different types of cancer in comparison with healthy tissue-resident T-cells. Thus, we analyzed the single cell transcriptome of five tumor-infiltrating CD4-T, CD8-T and Treg cells obtained from different types of cancer to identify specific pathways for each subset in malignant environments.

View Article and Find Full Text PDF

The current COVID-19 pandemic is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Many countries have reported the experience of at least two contagion waves, describing associated mortality rates and population behavior. The analysis of the effect of this pandemic in different localities can provide valuable information on the key factors to consider in the face of future massive infectious diseases.

View Article and Find Full Text PDF

The early detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using the real-time quantitative polymerase chain reaction (RT-qPCR) as a gold-standard molecular tool has allowed to test and trace the viral spread and the isolation of COVID-19-infected patients. The detection capacity of viral and internal genes is an essential parameter to consider and analyze during the assay. In this study, we analyze the performance of the two commercial RT-qPCR kits used in Chile, TaqMan™ 2019-nCoV Control Kit v1 (Thermo Fisher) and MaxCov19 (TAAG Genetics), for the COVID-19 diagnosis from nasopharyngeal swab samples (NPSs).

View Article and Find Full Text PDF
Article Synopsis
  • * Continuous RT-qPCR testing and genomic surveillance helped to identify a case of reinfection in a homeless individual 58 days after initial diagnosis, with different viral variants involved.
  • * It highlights the need for intensive genomic surveillance, particularly for vulnerable groups like homeless populations in Chile, who face health care access challenges and poor viral traceability.
View Article and Find Full Text PDF

Piscine orthoreovirus (PRV) is a virus in the genus Orthoreovirus of the Reoviridae family, first described in 2010 associated with Heart and Skeletal Muscle Inflammation (HSMI) in Atlantic salmon (). Three phases of PRV infection have been described, the early entry and dissemination, the acute dissemination phase, and the persistence phase. Depending on the PRV genotype and the host, infection can last for life.

View Article and Find Full Text PDF

is a marine zoonotic pathogen associated with fish farms that is considered a biomarker of climate change. Zoonotic strains trigger a rapid death of their susceptible hosts (fish or humans) by septicemia that has been linked to a cytokine storm in mice. Therefore, we hypothesize that also causes fish death by triggering a cytokine storm in which red blood cells (RBCs), as nucleated cells in fish, could play an active role.

View Article and Find Full Text PDF
Article Synopsis
  • Vaccine administration is key in the fight against COVID-19, but emerging variants like B.1.621 (Mu) can challenge vaccine-induced immunity.
  • A study from Santiago, Chile, compares four fully vaccinated patients (with CoronaVac) who exhibited varying symptoms of COVID-19 to four unvaccinated patients, revealing that the unvaccinated had more severe symptoms.
  • The findings indicate that vaccinated individuals generally experience milder symptoms, suggesting that the CoronaVac vaccine provides protective effects against the B.1.621 (Mu) variant.
View Article and Find Full Text PDF

CoronaVac vaccine from Sinovac Life Science is currently being used in several countries. In Chile, the effectiveness of preventing hospitalization is higher than 80% with a vaccination schedule. However, to date, there are no data about immune response induction or specific memory.

View Article and Find Full Text PDF

Timely detection of severe acute respiratory syndrome due to coronavirus 2 (SARS-CoV-2) by reverse transcription quantitative polymerase chain reaction (RT-qPCR) has been the gold- strategy for identifying positive cases during the current pandemic. However, faster and less expensive methodologies are also applied for the massive diagnosis of COVID-19. In this way, the rapid antigen test (RAT) is widely used.

View Article and Find Full Text PDF