San Román Aberasturi, Beatriz

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https://academica-e.unavarra.es/handle/2454/49988

Last Name

San Román Aberasturi

First Name

Beatriz

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Producción Agraria

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0000-0003-1195-0100

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7809

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Open Access
Mutants in the lipopolysaccharide of Brucella ovis are attenuated and protect against B. ovis infection in mice
(BioMed Central, 2014) Soler Lloréns, Pedro; Gil Ramírez, Yolanda; Zabalza Baranguá, Ana; Iriarte, Maite; Conde Álvarez, Raquel; Zúñiga Ripa, Amaia; San Román Aberasturi, Beatriz; Zygmunt, Michel; Vizcaíno, Nieves; Cloeckaert, Axel; Grilló Dolset, María Jesús; Moriyón Uría, Ignacio; López Goñi, Ignacio; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
Brucella spp. are Gram-negative bacteria that behave as facultative intracellular parasites of a variety of mammals. This genus includes smooth (S) and rough (R) species that carry S and R lipopolysaccharides (LPS), respectively. S-LPS is a virulence factor, and mutants affected in the S-LPS O-polysaccharide (R mutants), core oligosaccharide or both show attenuation. However, B. ovis is naturally R and is virulent in sheep. We studied the role of B. ovis LPS in virulence by mutating the orthologues of wadA, wadB and wadC, three genes known to encode LPS core glycosyltransferases in S brucellae. When mapped with antibodies to outer membrane proteins (Omps) and R-LPS, wadB and wadC mutants displayed defects in LPS structure and outer membrane topology but inactivation of wadA had little or no effect. Consistent with these observations, the wadB and wadC but not the wadA mutants were attenuated in mice. When tested as vaccines, the wadB and wadC mutants protected mice against B. ovis challenge. The results demonstrate that the LPS core is a structure essential for survival in vivo not only of S brucellae but also of a naturally R Brucella pathogenic species, and they confirm our previous hypothesis that the Brucella LPS core is a target for vaccine development. Since vaccine B. melitensis Rev 1 is S and thus interferes in serological testing for S brucellae, wadB mutant represents a candidate vaccine to be evaluated against B. ovis infection of sheep suitable for areas free of B. melitensis.
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Desarrollo y valoración de la eficacia vacunal in vivo de extractos salinos y bacterinas derivados de mutantes rugosos de Salmonella Enteriditis, junto con moléculas inmunoestimuladoras.
(2009) San Román Aberasturi, Beatriz; Farrán Blanch, Inmaculada; Escuela Técnica Superior de Ingenieros Agrónomos; Nekazaritza Ingeniarien Goi Mailako Eskola Teknikoa; Producción Agraria; Nekazaritza Ekoizpena
Open Access
Deletion of the GI-2 integrase and the wbkA flanking transposase improves the stability of Brucella melitensis Rev 1 vaccine
(BioMed Central, 2013) Mancilla, Marcos; Grilló Dolset, María Jesús; Miguel López, María Jesús de; López Goñi, Ignacio; San Román Aberasturi, Beatriz; Zabalza Baranguá, Ana; Moriyón Uría, Ignacio; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
Brucella melitensis Rev 1 is the best vaccine available for the prophylaxis of small ruminant brucellosis and, indirectly, for reducing human brucellosis. However, Rev 1 shows anomalously high rates of spontaneous dissociation from smooth (S) to rough (R) bacteria, the latter being inefficacious as vaccines. This S-R instability results from the loss of the O-polysaccharide. To overcome this problem, we investigated whether some recently described mechanisms promoting mutations in O-polysaccharide genes were involved in Rev 1 S-R dissociation. We found that a proportion of Rev 1 R mutants result from genome rearrangements affecting the wbo O-polysaccharide loci of genomic island GI-2 and the wbkA O-polysaccharide glycosyltransferase gene of the wbk region. Accordingly, we mutated the GI-2 int gene and the wbk IS transposase involved in those arrangements, and found that these Rev 1 mutants maintained the S phenotype and showed lower dissociation levels. Combining these two mutations resulted in a strain (Rev 2) displaying a 95% decrease in dissociation with respect to parental Rev 1 under conditions promoting dissociation. Rev 2 did not differ from Rev 1 in the characteristics used in Rev 1 typing (growth rate, colonial size, reactivity with O-polysaccharide antibodies, phage, dye and antibiotic susceptibility). Moreover, Rev 2 and Rev 1 showed similar attenuation and afforded similar protection in the mouse model of brucellosis vaccines. We conclude that mutations targeting genes and DNA sequences involved in spontaneous O-polysaccharide loss enhance the stability of a critical vaccine phenotype and complement the empirical stabilization precautions taken during S Brucella vaccine production.
Open Access
Sensitivity of the ISO 6579:2002/Amd 1:2007 standard method for detection of Salmonella spp. on mesenteric lymph nodes from slaughter pigs
(American Society for Microbiology, 2012) Mainar Jaime, Raúl Carlos; Andrés, S.; Vico, J. P.; San Román Aberasturi, Beatriz; Garrido González, Victoria; Grilló Dolset, María Jesús; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua; Gobierno de Navarra / Nafarroako Gobernua, IIQ14064.RI1; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
The ISO 6579:2002/Amd 1:2007 (ISO) standard has been the bacteriological standard method used in the European Union for the detection of Salmonella spp. in pig mesenteric lymph nodes (MLN), but there are no published estimates of the diagnostic sensitivity (Se) of the method in this matrix. Here, the Se of the ISO (SeISO) was estimated on 675 samples selected from two populations with different Salmonella prevalences (14 farms with a ≥20% prevalence and 13 farms with a<20% prevalence) and through the use of latent-class models in concert with Bayesian inference, assuming 100% ISO specificity, and an invA-based PCR as the second diagnostic method. The SeISO was estimated to be close to 87%, while the sensitivity of the PCR reached up to 83.6% and its specificity was 97.4%. Interestingly, the bacteriological reanalysis of 33 potential false-negative (PCR-positive) samples allowed isolation of 19 (57.5%) new Salmonella strains, improving the overall diagnostic accuracy of the bacteriology. Considering the usual limitations of bacteriology regarding Se, these results support the adequacy of the ISO for the detection of Salmonella spp. from MLN and also that of the PCR-based method as an alternative or complementary (screening) test for the diagnosis of pig salmonellosis, particularly considering the cost and time benefits of the molecular procedure.
Open Access
Study of compartmentalization in the visna clinical form of small ruminant lentivirus infection in sheep
(BioMed Central, 2012) Ramírez Álvarez, Hugo; Reina Arias, Ramsés; Bertolotti, Luigi; Cenoz García, Amaia; Hernández, Mirna Margarita; San Román Aberasturi, Beatriz; Glaría Ezquer, Idoia; Andrés, Ximena de; Crespo Otano, Helena; Jauregui, Paula; Benavides, Julio; Polledo, Laura; Pérez, Valentín; García Marín, Juan F.; Rosati, Sergio; Amorena Zabalza, Beatriz; Andrés Cara, Damián de; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua; Gobierno de Navarra / Nafarroako Gobernua: IIQ010449.RI1; Gobierno de Navarra / Nafarroako Gobernua: IIQ14064.RI1; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Background: A central nervous system (CNS) disease outbreak caused by small ruminant lentiviruses (SRLV) has triggered interest in Spain due to the rapid onset of clinical signs and relevant production losses. In a previous study on this outbreak, the role of LTR in tropism was unclear and env encoded sequences, likely involved in tropism, were not investigated. This study aimed to analyze heterogeneity of SRLV Env regions - TM amino terminal and SU V4, C4 and V5 segments - in order to assess virus compartmentalization in CNS. Results: Eight Visna (neurologically) affected sheep of the outbreak were used. Of the 350 clones obtained after PCR amplification, 142 corresponded to CNS samples (spinal cord and choroid plexus) and the remaining to mammary gland, blood cells, bronchoalveolar lavage cells and/or lung. The diversity of the env sequences from CNS was 11.1-16.1% between animals and 0.35-11.6% within each animal, except in one animal presenting two sequence types (30% diversity) in the CNS (one grouping with those of the outbreak), indicative of CNS virus sequence heterogeneity. Outbreak sequences were of genotype A, clustering per animal and compartmentalizing in the animal tissues. No CNS specific signature patterns were found. Conclusions: Bayesian approach inferences suggested that proviruses from broncoalveolar lavage cells and peripheral blood mononuclear cells represented the common ancestors (infecting viruses) in the animal and that neuroinvasion in the outbreak involved microevolution after initial infection with an A-type strain. This study demonstrates virus compartmentalization in the CNS and other body tissues in sheep presenting the neurological form of SRLV infection.
Open Access
The extradomain a of fibronectin enhances the efficacy of lipopolysaccharide defective Salmonella bacterins as vaccines in mice
(BioMed Central, 2012) San Román Aberasturi, Beatriz; Lasa Uzcudun, Íñigo; Andrés Cara, Damián de; Amorena Zabalza, Beatriz; Lasarte, Juan José; Grilló Dolset, María Jesús; Garrido González, Victoria; Muñoz Álvaro, Pilar María; Arribillaga, Laura; García Martínez, Begoña; Andrés, Ximena de; Zabaleta Sanz de Acedo, Virginia; Mansilla, Cristina; Farrán Blanch, Inmaculada; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua; Gobierno de Navarra / Nafarroako Gobernua: IIM10865.RI1-EP12; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
The Extradomain A from fibronectin (EDA) has an immunomodulatory role as fusion protein with viral and tumor antigens, but its effect when administered with bacteria has not been assessed. Here, we investigated the adjuvant effect of EDA in mice immunizations against Salmonella enterica subspecies enterica serovar Enteritidis (Salmonella Enteritidis). Since lipopolysaccharide (LPS) is a major virulence factor and the LPS O-polysaccharide (O-PS) is the immunodominant antigen in serological diagnostic tests, Salmonella mutants lacking O-PS (rough mutants) represent an interesting approach for developing new vaccines and diagnostic tests to differentiate infected and vaccinated animals (DIVA tests). Here, antigenic preparations (hot-saline extracts and formalin-inactivated bacterins) from two Salmonella Enteritidis rough mutants, carrying either intact (SE Delta waaL) or deep-defective (SE Delta gal) LPS-Core, were used in combination with EDA. Biotinylated bacterins, in particular SE Delta waaL bacterin, decorated with EDAvidin (EDA and streptavidin fusion protein) improved the protection conferred by hot-saline or bacterins alone and prevented significantly the virulent infection at least to the levels of live attenuated rough mutants. These findings demonstrate the adjuvant effect of EDAvidin when administered with biotinylated bacterins from Salmonella Enteritidis lacking O-PS and the usefulness of BEDA-SE Delta waaL as non-live vaccine in the mouse model.
Open Access
Simultaneous infections by different Salmonella strains in mesenteric lymph nodes of finishing pigs
(BioMed Central, 2014) Garrido González, Victoria; Sánchez Alarcón, Samanta Rita; San Román Aberasturi, Beatriz; Zabalza Baranguá, Ana; Díaz Tendero, Yasmín; Frutos, Cristina de; Mainar Jaime, Raúl Carlos; Grilló Dolset, María Jesús; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua; Gobierno de Navarra / Nafarroako Gobernua: IIQ14064.RI1; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Background: Salmonellosis is a major worldwide zoonosis, and Salmonella-infected finishing pigs are considered one of the major sources of human infections in developed countries. Baseline studies on salmonellosis prevalence in fattening pigs in Europe are based on direct pathogen isolation from mesenteric lymph nodes (MLN). This procedure is considered the most reliable for diagnosing salmonellosis in apparently healthy pigs. The presence of simultaneous infections by different Salmonella strains in the same animal has never been reported and could have important epidemiological implications. Results: Fourteen finishing pigs belonging to 14 farms that showed high salmonellosis prevalence and a variety of circulating Salmonella strains, were found infected by Salmonella spp, and 7 of them were simultaneously infected with strains of 2 or 3 different serotypes. Typhimurium isolates showing resistance to several antimicrobials and carrying mobile integrons were the most frequently identified in the colonized MLN. Four animals were found infected by Salmonella spp. of a single serotype (Rissen or Derby) but showing 2 or 3 different antimicrobial resistance profiles, without evidence of mobile genetic element exchange in vivo. Conclusion: This is the first report clearly demonstrating that pigs naturally infected by Salmonella may harbour different Salmonella strains simultaneously. This may have implications in the interpretation of results from baseline studies, and also help to better understand human salmonellosis outbreaks and the horizontal transmission of antimicrobial resistance genes.