Person:
Álvarez Sánchez, Julio

Profile Picture
First Name
Julio
Last Name
Álvarez Sánchez
URI
https://hdl.handle.net/20.500.14352/81087
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Veterinaria
Department
Sanidad Animal
Area
Identifiers
UCM identifierORCIDScopus Author IDWeb of Science ResearcherIDDialnet ID

Filters

2012 - 201912020 - 20231
Reset filters

Settings

Start date: 2010 × Subject: 579.62 ×

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Evaluation of the sensitivity and specificity of bovine tuberculosis diagnostic tests in naturally infected cattle herds using a Bayesian approach
    (Veterinary Microbiology, 2012) Álvarez Sánchez, Julio; Perez, Andrés; Bezos Garrido, Javier; Marqués, Sergio; Grau, Anna; Saez, Jose Luis; Mínguez, Olga; Juan Ferré, Lucía De; Domínguez Rodríguez, Lucas José
    Test-and-slaughter strategies have been the basis of bovine tuberculosis (BT) eradication programs worldwide; however, eradication efforts have not succeeded in certain regions, and imperfect sensitivity and specificity of applied diagnostic techniques have been deemed as one of the possible causes for such failure. Evaluation of tuberculosis diagnostic tools has been impaired by the lack of an adequate gold standard to define positive and negative individuals. Here, a Bayesian approach was formulated to estimate for the first time sensitivity (Se) and specificity (Sp) of the tests [single intradermal tuberculin (SIT) test, and interferon-gamma (IFN-γ) assay] currently used in Spain. Field data from the first implementation of IFN-γ assay (used in parallel with SIT test 2-6months after a first disclosure SIT test) in infected beef, dairy and bullfighting cattle herds from the region of Castilla and Leon were used for the analysis. Model results suggested that in the described situation: (i) Se of SIT test was highly variable (40.1-92.2% for severe interpretation, median=66-69%), and its Sp was high (>99%) regardless interpretation criteria; (ii) IFN-γ assay showed a high Se (median=89-90% and 83.5% for 0.05 and 0.1 cut-off points respectively) and an acceptable Sp (85.7% and 90.3% for 0.05 and 0.1 thresholds) and (iii) parallel application of both tests maximized the combined Se (95.6% using severe SIT and 0.05 cut-off point in the IFN-γ assay). These results support the potential use of the IFN-γ assay as an ancillary technique for routine BT diagnosis.
  • Thumbnail Image
    Item
    New insights into the pathogenesis and transmission of Brucella pinnipedialis: systemic infection in two bottlenose dolphins (Tursiops truncatus)
    (Microbiology Spectrum, 2023) Vargas Castro, Ignacio; Crespo Picazo, José Luis; Fayos, Manena; Jiménez Martínez, María De Los Ángeles; Torre Fuentes, Laura; Álvarez Sánchez, Julio; Moura, André E.; Hernández, Marta; Buendía Andrés, Aranzazu; Barroso Arévalo, Sandra; García-Seco Romero, María Teresa; Pérez Sancho, Marta; De Miguel, María Jesús; Andrés Barranco, Sara; Marco Cabedo, Vicente; Peñín Villahoz, Gaizka; Muñoz, Pilar María; Domínguez Rodríguez, Lucas José; García Párraga, Daniel; Sánchez-Vizcaíno Rodríguez, José Manuel
    The emergence of Brucella infections in marine mammals is a growing concern. The present study reports two cases of systemic Brucella pinnipedialis infection detected in bottlenose dolphins (Tursiops truncatus) pair stranded together in the Cantabrian coast of Spain. Both animals showed systemic lesions associated with the Brucella infection, more severe in the younger dolphin, considered the likely offspring of the other individual. Real-time PCR, bacterial culture, and whole-genome sequencing were used to detect and characterize the Brucella strains involved in both dolphins. The phylogenetic analysis performed on the Brucella genomes retrieved revealed that the species involved was B. pinnipedialis (ST25). Both animals resulted seropositive in a commercial multispecies blocking ELISA but tested negative in the standard Rose Bengal test. To the best of our knowledge, this is the first report of a systemic infection resulting in various lesions associated with Brucella pinnipedialis (ST25) in two bottlenose dolphins. It is also the initial isolation of Brucella in the milk of a non-pregnant or non-aborting female cetacean likely stranded with its offspring. These findings provide new insights into the epidemiology and clinical impact of B. pinnipedialis infection in cetaceans and underscore the importance of continued diagnostic surveillance to gain better understanding of brucellosis effects and transmission in marine mammal populations.