Person: Bezos Garrido, Javier
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First Name
Javier
Last Name
Bezos Garrido
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Veterinaria
Department
Sanidad Animal
Area
Sanidad Animal
Identifiers
5 results
Search Results
Now showing 1 - 5 of 5
Item Molecular epidemiology of Types I/III strains of Mycobacterium avium subspecies paratuberculosis isolated from goats and cattle(Veterinary Microbiology, 2006) Juan Ferré, Lucía De; Álvarez Sánchez, Julio; Aranaz Martín, Alicia; Rodríguez Bertos, Antonio Manuel; Romero Martínez, Beatriz; Bezos Garrido, Javier; Mateos García, Ana Isabel; Domínguez Rodríguez, Lucas JoséMolecular characterization of Mycobacterium avium subsp. paratuberculosis (M. a. paratuberculosis) isolates classifies them into three groups: cattle or Type II, sheep or Type I, and intermediate or Type III. To avoid problems associated with characterization of extremely slow growth strains, PCR-based techniques that divide the M. a. paratuberculosis strains in two main groups (cattle or Type II, and sheep or Types I/III) can be performed. The objectives of this study were to characterize the M. a. paratuberculosis isolates identified by different PCR-based tests (IS1311-PCR and restriction endonuclease analysis, PCR test based on a DNA sequence difference, and a PCR aimed at three Type I-specific loci), and to determine the clinical and epidemiological implications of Types I/III M. a. paratuberculosis strains in livestock. One hundred and fifty-eight M. a. paratuberculosis strains from domestic ruminants were analyzed. One hundred and six M. a. paratuberculosis isolates (61 from goats and 45 from cattle) were classified as Type II strains; and 52 (29 from cows, 20 from goats, and three from sheep) were included in the Types I/III. The Types I/III M. a. paratuberculosis strains were associated to Spanish native breeds. The majority of these animals had not been in direct or indirect contact with sheep flocks infected with M. a. paratuberculosis. This fact should be taken into account when implementing paratuberculosis control programs.Item Spoligotyping Profile Change Caused by Deletion of a Direct Variable Repeat in a Mycobacterium tuberculosis Isogenic Laboratory Strain(Journal of Clinical Microbiology, 2004) Aranaz Martín, Alicia; Romero Martínez, Beatriz; Montero Serra, Natalia; Álvarez Sánchez, Julio; Bezos Garrido, Javier; Juan Ferré, Lucía De; Mateos García, Ana Isabel; Domínguez Rodríguez, Lucas JoséSpoligotyping is a major tool for molecular typing of Mycobacterium tuberculosis complex organisms. For epidemiological purposes, strains are considered clonal only when their spoligotyping patterns are identical. We report a change in the spoligotyping profiles of truly isogenic strains (a clinical isolate and a subculture derived in the laboratory) caused by deletion of a direct variable repeat. Without the information about the relationship between them, a link between these strains would have gone unnoticed. Evolutionary events should be taken into account in the interpretation of spoligotyping results and in the design of databases.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 JoséTest-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.Item Comparison of four different culture media for isolation and growth of type II and type I/III Mycobacterium avium subsp. paratuberculosis strains isolated from cattle and goats(Applied and Environmental Microbiology, 2006) Juan Ferré, Lucía De; Álvarez Sánchez, Julio; Romero Martínez, Beatriz; Bezos Garrido, Javier; Castellanos, Elena; Aranaz Martín, Alicia; Mateos García, Ana Isabel; Domínguez Rodríguez, Lucas JoséCulture is considered the definitive technique for Johne's disease diagnosis, and it is essential for later applications of certain molecular typing techniques. In this study, we have tested four solid media (Herrold's egg yolk medium [HEYM] with sodium pyruvate and mycobactin [HEYMm-SP], HEYM with mycobactin and without sodium pyruvate [HEYMm], Middlebrook 7H11 with mycobactin [Mm], and Löwenstein-Jensen with mycobactin [LJm]) for isolation of Mycobacterium avium subsp. paratuberculosis strains in 319 tissue samples from cattle herds and goat flocks. We have shown that each of the two main groups of M. avium subsp. paratuberculosis (type II and type I/III) has different requirements for growth in the culture media studied. The recommended solid media for isolation of type I/III strains are LJm and Mm, since the combination of both media allowed the recovery of all these strains. The most widespread culture medium, HEYM, is not suitable for the isolation of this group of M. avium subsp. paratuberculosis strains. Regarding the type II strains, HEYMm-SP was the medium where more strains were isolated, but the other three media are also needed in order to recover all type II strains. The incubation period is also related to the strain type. In conclusion, because the type of strain cannot be known in advance of culture, coupled with the fact that cattle and goats can be infected with both groups of strains, we recommend the use of the four solid media and the prolongation of the incubation period to more than 6 months to detect paratuberculous herds/flocks and to determine the true prevalence of the infection.Item Molecular Epidemiology of Multidrug-Resistant Mycobacterium bovis Isolates with the Same Spoligotyping Profile as Isolates from Animals(JOURNAL OF CLINICAL MICROBIOLOGY, 2006) Romero Martínez, Beatriz; Aranaz Martín, Alicia; Juan Ferré, Lucía De; Álvarez Sánchez, Julio; Bezos Garrido, Javier; Mateos García, Ana Isabel; Enrique Gómez-Mampaso; Domínguez Rodríguez, Lucas JoséPCR-based characterization techniques have been adopted in most laboratories for Mycobacterium bovis typing. We report a molecular characterization of human multidrug-resistant M. bovis isolates and three bovine isolates that share the spoligotyping profile. The analysis of the direct repeat region showed that both groups differed in the presence of spacers not included in the current membrane. They were also distinguished by two out of the nine mycobacterial interspersed repetitive unit variable-number tandem repeat loci tested, indicating that the human infection was not acquired from the cattle from which isolates were obtained. These results highlight that a combination of techniques is required for appropriate discrimination, even for those spoligotypes that have a low frequency.