Browsing by Author "de Oca, Marco Montes"

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    Bacterial networks in Atlantic salmon with Piscirickettsiosis
    (Springer Nature, 2023) Coca Rives, Yoandy; Godoy, Marcos; Pontigo, Juan Pablo; Caro, Diego; Maracaja-Coutinho, Vinicius; Arias-Carrasco, Raul; Rodriguez-Cordova, Leonardo; de Oca, Marco Montes; Saez-Navarrete, Cesar; Burbulis, Ian
    An unbalanced composition of gut microbiota in fish is hypothesized to play a role in promoting bacterial infections, but the synergistic or antagonistic interactions between bacterial groups in relation to fish health are not well understood. We report that pathogenic species in the Piscirickettsia, Aeromonas, Renibacterium and Tenacibaculum genera were all detected in the digesta and gut mucosa of healthy Atlantic salmon without clinical signs of disease. Although Piscirickettsia salmonis (and other pathogens) occurred in greater frequencies of fish with clinical Salmonid Rickettsial Septicemia (SRS), the relative abundance was about the same as that observed in healthy fish. Remarkably, the SRS-positive fish presented with a generalized mid-gut dysbiosis and positive growth associations between Piscirickettsiaceae and members of other taxonomic families containing known pathogens. The reconstruction of metabolic phenotypes based on the bacterial networks detected in the gut and mucosa indicated the synthesis of Gram-negative virulence factors such as colanic acid and O-antigen were over-represented in SRS positive fish. This evidence indicates that cooperative interactions between organisms of different taxonomic families within localized bacterial networks might promote an opportunity for P. salmonis to cause clinical SRS in the farm environment.
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    Differential neutralizing antibody responses elicited by CoronaVac and BNT162b2 against SARS-CoV-2 Lambda in Chile
    (2022) Acevedo, Monica L.; Gaete-Argel, Aracelly; Alonso-Palomares, Luis; de Oca, Marco Montes; Bustamante, Andres; Gaggero, Aldo; Paredes, Fabio; Cortes, Claudia P.; Pantano, Sergio; Martinez-Valdebenito, Constanza; Angulo, Jenniffer; Le Corre, Nicole; Ferres, Marcela; Navarrete, Marcelo A.; Valiente-Echeverria, Fernando; Soto-Rifo, Ricardo
    The SARS-CoV-2 Lambda variant has been prevalent in Latin America. An analysis of the neutralization capacity of antibodies elicited by CoronaVac and BNT162b2 against SARS-CoV-2 Lambda in plasma from healthcare workers and patients in Chile reveals that BNT162b2 elicits higher neutralizing antibody titres than CoronaVac.
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    Isolation of a New Infectious Pancreatic Necrosis Virus (IPNV) Variant from Genetically Resistant Farmed Atlantic Salmon (Salmo salar) during 2021-2022
    (2022) Godoy, Marcos; Kibenge, Molly J. T.; de Oca, Marco Montes; Pontigo, Juan Pablo; Coca, Yoandy; Caro, Diego; Kusch, Karina; Suarez, Rudy; Burbulis, Ian; Kibenge, Frederick S. B.
    Infectious pancreatic necrosis (IPN), caused by IPNV, affects several species of farmed fish, particularly Atlantic salmon, and is responsible for significant economic losses in salmon aquaculture globally. Despite the introduction of genetically resistant farmed Atlantic salmon and vaccination strategies in the Chilean salmon industry since 2019, the number of IPN outbreaks has been increasing in farmed Atlantic salmon in the freshwater phase. This study examined gross and histopathological lesions of IPNV-affected fish, as well as the IPNV nucleotide sequence encoding the VP2 protein in clinical cases. The mortality reached 0.4% per day, and the cumulative mortality was from 0.4 to 3.5%. IPNV was isolated in the CHSE-214 cell line and was confirmed by RT-PCR, and VP2 sequence analysis. The analyzed viruses belong to IPNV genotype 5 and have 11 mutations in their VP2 protein. This is the first report of IPN outbreaks in farmed Atlantic salmon genetically resistant to IPNV in Chile. Similar outbreaks were previously reported in Scotland and Norway during 2018 and 2019, respectively. This study highlights the importance of maintaining a comprehensive surveillance program in conjunction with the use of farmed Atlantic salmon genetically resistant to IPNV.
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    Microbiome Dynamics of Salmo salar Skin and Gill
    (2023) Godoy, Marcos; Coca, Yoandy; Suarez, Rudy; de Oca, Marco Montes; Bledsoe, Jacob W.; Burbulis, Ian; Caro, Diego; Pontigo, Juan Pablo; Maracaja-Coutinho, Vinicius; Arias-Carrasco, Raul; Rodriguez Cordova, Leonardo Andres; Saez-Navarrete, Cesar
    Maintaining the high overall health of farmed animals is a central tenant of their well-being and care. Intense animal crowding in aquaculture promotes animal especially in the absence of straightforward methods for monitoring their health. Here, we used bacterial 16S ribosomal RNA gene sequencing to measure population dynamics occurring during P. salmonis outbreaks. Our findings revealed a complex bacterial community consisting of a previously undescribed core pathobiome. Notably, we detected Aliivibrio wodanis and Tenacibaculum dicentrarchi on the skin ulcers of salmon infected with P. salmonis, while Vibrio spp. were enriched on infected gills. The prevalence of these co-occurring networks indicates the influence that coinfection plays in P. salmonis pathogenicity.