Person: Rebollada Merino, Agustín Miguel
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First Name
Agustín Miguel
Last Name
Rebollada Merino
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Veterinaria
Department
Medicina y Cirugía Animal
Area
Identifiers
7 results
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Item First detection of Flavobacterium psychrophilum in juvenile Siberian sturgeons (Acipenser baerii) and description of the pathological findings(Journal of Fish Diseases, 2023) Chinchilla Rodríguez, Blanca; Vázquez Fernández, Esther; Rebollada Merino, Agustín Miguel; Pérez Sancho, Marta; Domínguez Rodríguez, Lucas José; Rodríguez Bertos, Antonio ManuelFlavobacterium psychrophilum affects many cultured fish species and is considered one of the most important bacterial pathogens causing substantial economic losses in salmonid aquaculture worldwide. Here, F. psychrophilum was identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and nested PCR as the aetiological agent causing mortality in diseased juvenile Siberian sturgeons (Acipenser baerii) reared on a freshwater fish farm. Diseased sturgeons were lethargic and displayed dark skin pigmentation, increased mucus production and the presence of skin ulcerations and haemorrhages specially on the ventral side and the base of fins. The histological examination of fish revealed proliferative branchitis, ulcerative and necrotizing dermatitis and myositis, lymphoid tissue atrophy, liver and kidney degeneration and thrombosis. To the best of our knowledge, this is the first report describing the infection of Siberian sturgeons by F. psychrophilum. The detection of F. psychrophilum in diseased Siberian sturgeons and the description of the pathological findings observed during the outbreak may contribute to a better understanding of the bacterium pathogenicity and the range of fish species susceptible to infection.Item Histopathologic and immunohistochemical findings in the placentas and fetuses of domestic swine naturally infected with Brucella suis biovar 2(Journal of Veterinary Diagnostic Investigation, 2023) Rebollada Merino, Agustín Miguel; García-Seco Romero, María Teresa; Pérez Sancho, Marta; Domínguez Rodríguez, Lucas José; Rodríguez Bertos, Antonio ManuelPorcine brucellosis, which is caused by Brucella suis biovar (bv) 2, is a re-emerging disease that causes reproductive problems in pigs in Europe. The pathogenesis and lesions of B. suis intrauterine infection are poorly characterized; characterization could facilitate the diagnosis and investigation of porcine brucellosis. We collected samples of placentas and fetuses for histologic and microbiologic studies during an outbreak of abortions on a pig-breeding farm in Spain. Brucella was cultured from the vaginal swabs obtained from sows that had aborted, some placentas, and fetal tissues (spleen, liver, lung, gastric content); molecular testing confirmed B. suis bv 2 infection. Histologically, there was necrotizing and hemorrhagic placentitis; suppurative hepatitis; lymphoid depletion and sinusoidal histiocytosis in the spleen, lymph nodes, and thymus; and bronchointerstitial pneumonia. Hemorrhages were observed in the umbilical cord, heart, kidneys, and brain. We detected Brucella by immunohistochemistry (IHC) in all of the placentas and fetal organs studied, specifically in the trophoblasts of the chorionic epithelium, in the cytoplasm of macrophages in the chorionic stroma, and extracellularly in necrotic debris. Furthermore, we assessed the lymphocyte population in the placentas through the use of IHC (anti-CD3, anti- Pax5 antibodies), revealing that the lymphocytic response was composed of T cells but not B cells.Item Environment and Offspring Surveillance in Porcine Brucellosis(Frontiers in Veterinary Science, 2022) Rebollada Merino, Agustín Miguel; Pérez Sancho, Marta; Rodríguez Bertos, Antonio Manuel; García Benzaquén, Nerea; Martínez Alares, Irene; Navarro Gómez, Alejandro; Domínguez Rodríguez, Lucas José; García-Seco Romero, María TeresaPorcine brucellosis, caused by Brucella suis (B. suis), is a notifiable disease causing significant economic losses in production systems.Most infected pigsmay act as carriers and shed B. suis even if asymptomatic. This can contribute to environmental persistence, thus hindering control efforts. Here, the environment and the offspring were investigated during and after a B. suis outbreak at a sow breeding farm. The diagnosis of B. suis in sows (n = 1,140) was performed by culture and polymerase chain reaction (PCR) from vaginal swabs, indirect enzyme-linked immunosorbent assay (I-ELISA) from sera, and brucellin skin test (BST). B. suis diagnosis in post-weaning pigs (n = 899) was performed by I-ELISA in sera and BST. The environmental surveillance programme was implemented by placing gauze sponges (n = 175) pre-hydrated in a surfactant and inactivating liquid for Brucella DNA detection by PCR in different farm areas. Our results showed that the offspring of infected sows reacted to in vivo techniques for B. suis. Furthermore, the offspring born during the outbreak displayed higher seropositivity (I- ELISA) and reactivity (BST) than those pigs born after. Brucella DNA was detected in pregnant sow areas, boxes, boots, and post-weaning pig areas. In addition, Brucella DNA environmental detection was higher during the B. suis outbreak than the post B. suis outbreak. The environmental approach has proven to be a simple, practical, valuable, and safe method to detect and monitor B. suis. These results suggest a role of the environment and the offspring that should be considered in porcine brucellosis surveillance and control programmes.Item Immunopathology of early and advanced epididymis lesions caused by Brucella ovis in rams(Veterinary Immunology and Immunopathology, 2023) Rebollada Merino, Agustín Miguel; García-Seco Romero, María Teresa; Chinchilla Rodríguez, Blanca; Pérez Sancho, Marta; Domínguez Rodríguez, Lucas José; Rodríguez Bertos, Antonio ManuelOvine brucellosis is an infectious disease that causes alterations in the reproductive tract in ram and abortion in ewes. Their negative economic impact in ovine production warrants a thorough understanding the interactions between B. ovis and the host. Here, epididymis lesions of rams infected by B. ovis were histopathologically staged into early and advanced. Expression by immunohistochemistry of Brucella antigens, inflammatory cell markers (CD3, CD79αcy) and cytokines (IFN-γ, TNF-α, TGF-β1) was assessed in both stages. Early lesions were characterized by epithelial changes, interstitial inflammation, and mild fibrosis; whereas advanced lesions displayed caseous granulomas containing numerous macrophages, multinucleated giant cells, lymphocytes, and plasma cells. Expression of Brucella antigens were observed in both stages. The cellular response in B. ovis lesions were predominantly of T-cells (CD3+) whereas low numbers of B-cells and plasma cells (CD79αcy+) were present in both early and advanced lesions. IFN-γ was expressed by lymphocytes in early lesions suggesting that the adaptive immune response against B. ovis is initiated by Th1 cells, this response was also preserved in advanced stages. Expression of TNF-α was observed in neutrophils of epithelial microabscesses and intraepithelial T-cells of early lesions suggesting a promotion of neutrophil phagocytosis triggered by TNF-α. On the other hand, advanced lesions showed a reduction of TNF-α expression which may permit B. ovis persistence in granulomas. Lastly, TGF-β1 expression (fibroblast, macrophages and less in lymphocytes) were increased with time, suggesting that B. ovis promotes TGF-β1 secretion promoting chronicity of the lesions.Item First detection of Flavobacterium psychrophilum in juvenile Siberian sturgeons (Acipenser baerii) and description of the pathological findings(Journal of fish diseases, 2023) Chinchilla Rodríguez, Blanca; Vázquez Fernández, Esther; Rebollada Merino, Agustín Miguel; Pérez Sancho, Marta; Domínguez Rodríguez, Lucas José; Rodríguez Bertos, Antonio ManuelFlavobacterium psychrophilum affects many cultured fish species and is considered one of the most important bacterial pathogens causing substantial economic losses in salmonid aquaculture worldwide. Here, F. psychrophilum was identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and nested PCR as the aetiological agent causing mortality in diseased juvenile Siberian sturgeons (Acipenser baerii) reared on a freshwater fish farm. Diseased sturgeons were lethargic and displayed dark skin pigmentation, increased mucus production and the presence of skin ulcerations and haemorrhages specially on the ventral side and the base of fins. The histological examination of fish revealed proliferative branchitis, ulcerative and necrotizing dermatitis and myositis, lymphoid tissue atrophy, liver and kidney degeneration and thrombosis. To the best of our knowledge, this is the first report describing the infection of Siberian sturgeons by F. psychrophilum. The detection of F. psychrophilum in diseased Siberian sturgeons and the description of the pathological findings observed during the outbreak may contribute to a better understanding of the bacterium pathogenicity and the range of fish species susceptible to infection.Item Histopathology, Immunohistochemical Diagnosis, and Management of Penicillin-Resistant Staphylococcus delphini Cutaneous Infection in a Bottlenose Dolphin(Aquatic Mammals, 2023) Romani Cremaschi, Umberto; Rebollada Merino, Agustín Miguel; Canales, Rocío; Vargas Castro, Ignacio; Pérez Sancho, Marta; Sánchez-Vizcaíno Rodríguez, José Manuel; Domínguez Rodríguez, Lucas José; Rodríguez Bertos, Antonio ManuelItem Immunopathology of early and advanced epididymis lesions caused by Brucella ovis in rams(Veterinary Immunology and Immunopathology, 2023) Rebollada Merino, Agustín Miguel; García-Seco Romero, María Teresa; Chinchilla Rodríguez, Blanca; Pérez Sancho, Marta; Domínguez Rodríguez, Lucas José; Rodríguez Bertos, Antonio ManuelOvine brucellosis is an infectious disease that causes alterations in the reproductive tract in ram and abortion in ewes. Their negative economic impact in ovine production warrants a thorough understanding the interactions between B. ovis and the host. Here, epididymis lesions of rams infected by B. ovis were histopathologically staged into early and advanced. Expression by immunohistochemistry of Brucella antigens, inflammatory cell markers (CD3, CD79αcy) and cytokines (IFN-γ, TNF-α, TGF-β1) was assessed in both stages. Early lesions were characterized by epithelial changes, interstitial inflammation, and mild fibrosis; whereas advanced lesions displayed caseous granulomas containing numerous macrophages, multinucleated giant cells, lymphocytes, and plasma cells. Expression of Brucella antigens were observed in both stages. The cellular response in B. ovis lesions were predominantly of T-cells (CD3+) whereas low numbers of B-cells and plasma cells (CD79αcy+) were present in both early and advanced lesions. IFN-γ was expressed by lymphocytes in early lesions suggesting that the adaptive immune response against B. ovis is initiated by Th1 cells, this response was also preserved in advanced stages. Expression of TNF-α was observed in neutrophils of epithelial microabscesses and intraepithelial T-cells of early lesions suggesting a promotion of neutrophil phagocytosis triggered by TNF-α. On the other hand, advanced lesions showed a reduction of TNF-α expression which may permit B. ovis persistence in granulomas. Lastly, TGF-β1 expression (fibroblast, macrophages and less in lymphocytes) were increased with time, suggesting that B. ovis promotes TGF-β1 secretion promoting chronicity of the lesions.