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Pilar M. Muñoz - One of the best experts on this subject based on the ideXlab platform.
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Development of attenuated live vaccine candidates against Swine Brucellosis in a non-zoonotic B. suis biovar 2 background
Veterinary Research, 2020Co-Authors: Beatriz Aragón-aranda, María Jesús De Miguel, Leticia Lázaro-antón, Miriam Salvador-bescós, Amaia Zúñiga-ripa, Ignacio Moriyón, Maite Iriarte, Pilar M. Muñoz, Raquel Conde-ÁlvarezAbstract:AbstractBrucella is a genus of gram-negative bacteria that cause Brucellosis. B. abortus and B. melitensis infect domestic ruminants while B. suis (biovars 1–3) infect Swine, and all these bacteria but B. suis biovar 2 are zoonotic. Live attenuated B. abortus S19 and B. melitensis Rev1 are effective vaccines in domestic ruminants, though both can infect humans. However, there is no Swine Brucellosis vaccine. Here, we investigated the potential use as vaccines of B. suis biovar 2 rough (R) lipopolysaccharide (LPS) mutants totally lacking O-chain (Bs2ΔwbkF) or only producing internal O-chain precursors (Bs2Δwzm) and mutants with a smooth (S) LPS defective in the core lateral branch (Bs2ΔwadB and Bs2ΔwadD). We also investigated mutants in the pyruvate phosphate dikinase (Bs2ΔppdK) and phosphoenolpyruvate carboxykinase (Bs2ΔpckA) genes encoding enzymes bridging phosphoenolpyruvate and the tricarboxylic acid cycle. When tested in the OIE mouse model at the recommended R or S vaccine doses (108 and 105 CFU, respectively), CFU/spleen of all LPS mutants were reduced with respect to the wild type and decreased faster for the R than for the S mutants. At those doses, protection against B. suis was similar for Bs2ΔwbkF, Bs2Δwzm, Bs2ΔwadB and the Rev1 control (105 CFU). As described before for B. abortus, B. suis biovar 2 carried a disabled pckA so that a double mutant Bs2ΔppdKΔpckA had the same metabolic phenotype as Bs2ΔppdK and ppdK mutation was enough to generate attenuation. At 105 CFU, Bs2ΔppdK also conferred the same protection as Rev1. As compared to other B. suis vaccine candidates described before, the mutants described here simultaneously carry irreversible deletions easy to identify as vaccine markers, lack antibiotic-resistance markers and were obtained in a non-zoonotic background. Since R vaccines should not elicit antibodies to the S-LPS and wzm mutants carry immunogenic O-chain precursors and did not improve Bs2ΔwbkF, the latter seems a better R vaccine candidate than Bs2Δwzm. However, taking into account that all R vaccines interfere in ELISA and other widely used assays, whether Bs2ΔwbkF is advantageous over Bs2ΔwadB or Bs2ΔppdK requires experiments in the natural host.
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Additional file 4 of Development of attenuated live vaccine candidates against Swine Brucellosis in a non-zoonotic B. suis biovar 2 background
2020Co-Authors: Beatriz Aragón-aranda, María Jesús De Miguel, Leticia Lázaro-antón, Miriam Salvador-bescós, Amaia Zúñiga-ripa, Ignacio Moriyón, Maite Iriarte, Pilar M. Muñoz, Raquel Conde-ÁlvarezAbstract:Additional file 4. Oligonucleotide sequences used for Bs2Δwzmand Bs2ΔwbkFmutant constructions.
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phylogeography and epidemiology of brucella suis biovar 2 in wildlife and domestic Swine
Veterinary Microbiology, 2019Co-Authors: Pilar M. Muñoz, María Jesús De Miguel, Virginie Mick, Lorena Sacchini, Anna Janowicz, Moulayali Cherfa, Celia Rodriguez Nevado, Guillaume Girault, Sara Andresbarranco, Maryne JayAbstract:Swine Brucellosis due to Brucella suis biovar 2 (bv2) is enzootic in wild boar and hare in continental Europe and may cause major economic losses to the pig industry, mainly in free-ranged pig farms. The high nucleotide identity found among the B. suis biovar 2 isolates has long hindered the full understanding of the epidemiology and the phylogeography of the disease. Here, we used multilocus variable-number tandem-repeat (VNTR) analysis (MLVA) and whole-genome analysis to identify single-nucleotide polymorphisms (SNPs) in order to gain insights from the largest B. suis bv2 dataset analyzed so far composed of domestic pigs and wildlife isolates collected throughout Europe since the 1970s. We found four major clades with a specific phylogeographic pattern. The Iberian clade contains isolates exclusively from the Iberian Peninsula. The Central European clade includes most isolates from France, Northern Italy, Switzerland and an important proportion of those of Northern Spain. The Eastern European clade clustered isolates from Croatia and Hungary mainly but also from areas of France, Germany, Italy and Poland. Finally, a separated Sardinian clade grouped three isolates from this island. At fine scale, MLVA demonstrated an endemic status of the infection in Europe and it allowed tracking a large outbreak formed by different farms from Spain linked to the same infection source. The whole genome SNP analysis showed that the strains form genetically distinct clades, shared between wild boar and pigs, in agreement with the MLVA clades. Interestingly, all hare isolates clustered together within two groups composed exclusively of wildlife isolates. Our results support the hypothesis that maintenance and spread of B. suis bv2 in Europe is a dynamic process linked to the natural expansion of wild boar as the main wild reservoir of the infection, while spread over long distances is found largely dependent on anthropogenic activities.
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Efficacy of antibiotic treatment and test-based culling strategies for eradicating Brucellosis in commercial Swine herds.
Preventive veterinary medicine, 2016Co-Authors: L. Dieste-pérez, Pilar M. Muñoz, Klaas Frankena, José M. Blasco, M.c.m. De JongAbstract:Swine Brucellosis caused by Brucella suis biovar 2 is an emerging disease in continental Europe. Without effective vaccines being available, the European Food Safety Authority (EFSA) recommends the full depopulation of infected herds as the only strategy to eradicate B. suis outbreaks. Using data collected from 8 herds suffering natural Swine Brucellosis outbreaks, we assessed the efficacy of four control strategies: (i) oxytetracycline treatment only, as a default scenario, (ii) oxytetracycline treatment combined with skin testing and removal of positive animals, (iii) oxytetracycline treatment combined with serological testing (Rose Bengal test-RBT-and indirect ELISA -iELISA-) and removal of seropositive animals and (iv) oxytetracycline treatment combined with both serological (RBT/iELISA) and skin testing and removal of positive animals. A Susceptible-Infectious-Removal model was used to estimate the reproduction ratio (R) for each strategy. According to this model, the oxytetracycline treatment alone was not effective enough to eradicate the infection. However, this antibiotic treatment combined with diagnostic testing at 4-monthly intervals plus immediate removal of positive animals showed to be effective to eradicate Brucellosis independent of the diagnostic test strategy used in an acceptable time interval (1-2 years), depending on the initial number of infected animals.
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Diagnostic performance of serological tests for Swine Brucellosis in the presence of false positive serological reactions.
Journal of microbiological methods, 2015Co-Authors: L. Dieste-pérez, Ignacio Moriyón, J. M. Blasco, M. J. De Miguel, Pilar M. MuñozAbstract:Swine Brucellosis caused by Brucella suis biovar 2 is an emerging disease in Europe. Currently used diagnostic tests for Swine Brucellosis detect antibodies to the O-polysaccharide (O-PS) of Brucella smooth lipopolysaccharide (S-LPS) but their specificity is compromised by false-positive serological reactions (FPSRs) when bacteria carrying cross-reacting O-PS infect pigs. FPSRs occur throughout Europe, and the only tool available for a specific B. suis diagnosis is the intradermal test with Brucella protein extracts free of O-PS or S-LPS. Using sera of 162 sows naturally infected by B. suis biovar 2, 406 Brucellosis-free sows, and 218 pigs of Brucellosis-free farms affected by FPSR, we assessed the diagnostic performance of an indirect ELISA with rough LPS (thus devoid of O-PS) and of gel immunodiffusion, counterimmunoelectrophoresis, latex agglutination and indirect ELISA with O-PS free proteins in comparison with several S-LPS tests (Rose Bengal, complement fixation, gel immunodiffusion and indirect ELISA). When adjusted to 100% specificity, the sensitivity of the rough LPS ELISA was very low (30%), and adoption of other cut-offs resulted in poor specificity/sensitivity ratios. Although their specificity was 100%, the sensitivity of protein tests (ELISA, latex agglutination, counterimmunoelectrophoresis, and gel immunodiffusion) was only moderate (45, 58, 61 and 63%, respectively). Among S-LPS tests, gel immunodiffusion was the only test showing acceptable sensitivity/specificity (68 and 100%, respectively). Despite these shortcomings, and when the purpose is to screen out FPSR at herd level, gel immunodiffusion tests may offer a technically simple and practical alternative to intradermal testing.
Jose De La Fuente - One of the best experts on this subject based on the ideXlab platform.
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Gene expression changes in spleens of the wildlife reservoir species, Eurasian wild boar (Sus scrofa), naturally infected with Brucella suis biovar 2
'Elsevier BV', 2017Co-Authors: Galindo, Ruth C., María Jesús De Miguel, Blasco, José M., Muñoz, Pilar M., Marín, Clara M., Gortázar Christian, Jose De La FuenteAbstract:Brucella suis is responsible for Swine Brucellosis worldwide. Of the five different B. suis biovars (bv.), bv. 2 appears restricted to Europe where it is frequently isolated from wild boar and hares, can infect pigs and can cause human Brucellosis. In this study, the differential gene expression profile was characterized in spleens of Eurasian wild boar naturally infected with B. suis bv. 2. Of the 20,201 genes analyzed in the microarray, 633 and 1,373 were significantly (fold change > 1.8; P < 0.01) upregulated and downregulated, respectively, in infected wild boar. The analysis was focused on genes that were over represented after conditional test for biological process gene ontology. Upregulated genes suggested that B. suis bv. 2 infection induced cell maturation, migration and/or proliferation in infected animals. The genes downregulated in infected wild boar impaired the activity of several important cellular metabolic pathways such as metabolism, cytoskeleton organization and biogenesis, immune response and lysosomal function and vesicle-mediated transport. In addition, the response to stress, sperm fertility, muscle development and apoptosis seemed to be also impaired in infected animals. These results suggested that B. suis bv. 2 may use strategies similar to other smooth brucellae to facilitate intracellular multiplication and the development of chronic infections. To our knowledge, this is the first report of the analysis of gene expression profile in hosts infected with B. suis bv. 2, which is important to understand the molecular mechanisms at the host-pathogen interface in the main reservoir species with possible implications in the zoonotic cycle of the pathogen.This work was supported by the Grupo Santander and Fundación Marcelino Botín, Spain (Project Control of Tuberculosis in Wildlife), Ministerio de Educación y Ciencia (MEC; Project AGL2005-07401) and FEDER, Spain. R.C. Galindo was funded by MEC, Spain.Peer Reviewe
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gene expression changes in spleens of the wildlife reservoir species eurasian wild boar sus scrofa naturally infected with brucella suis biovar 2
Journal of Genetics and Genomics, 2010Co-Authors: Ruth C Galindo, María Jesús De Miguel, Pilar M. Muñoz, J. M. Blasco, Clara M Marin, Javier Labairu, Miguel Revilla, Christian Gortazar, Jose De La FuenteAbstract:Brucella suis is responsible for Swine Brucellosis worldwide. Of the five different B. suis biovars (bv.), bv. 2 appears restricted to Europe where it is frequently isolated from wild boar and hares, can infect pigs and can cause human Brucellosis. In this study, the differential gene expression profile was characterized in spleens of Eurasian wild boar naturally infected with B. suis bv. 2. Of the 20,201 genes analyzed in the microarray, 633 and 1,373 were significantly (fold change > 1.8; P < 0.01) upregulated and downregulated, respectively, in infected wild boar. The analysis was focused on genes that were over represented after conditional test for biological process gene ontology. Upregulated genes suggested that B. suis bv. 2 infection induced cell maturation, migration and/or proliferation in infected animals. The genes downregulated in infected wild boar impaired the activity of several important cellular metabolic pathways such as metabolism, cytoskeleton organization and biogenesis, immune response and lysosomal function and vesicle-mediated transport. In addition, the response to stress, sperm fertility, muscle development and apoptosis seemed to be also impaired in infected animals. These results suggested that B. suis bv. 2 may use strategies similar to other smooth brucellae to facilitate intracellular multiplication and the development of chronic infections. To our knowledge, this is the first report of the analysis of gene expression profile in hosts infected with B. suis bv. 2, which is important to understand the molecular mechanisms at the host-pathogen interface in the main reservoir species with possible implications in the zoonotic cycle of the pathogen.
María Jesús De Miguel - One of the best experts on this subject based on the ideXlab platform.
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Development of attenuated live vaccine candidates against Swine Brucellosis in a non-zoonotic B. suis biovar 2 background
Veterinary Research, 2020Co-Authors: Beatriz Aragón-aranda, María Jesús De Miguel, Leticia Lázaro-antón, Miriam Salvador-bescós, Amaia Zúñiga-ripa, Ignacio Moriyón, Maite Iriarte, Pilar M. Muñoz, Raquel Conde-ÁlvarezAbstract:AbstractBrucella is a genus of gram-negative bacteria that cause Brucellosis. B. abortus and B. melitensis infect domestic ruminants while B. suis (biovars 1–3) infect Swine, and all these bacteria but B. suis biovar 2 are zoonotic. Live attenuated B. abortus S19 and B. melitensis Rev1 are effective vaccines in domestic ruminants, though both can infect humans. However, there is no Swine Brucellosis vaccine. Here, we investigated the potential use as vaccines of B. suis biovar 2 rough (R) lipopolysaccharide (LPS) mutants totally lacking O-chain (Bs2ΔwbkF) or only producing internal O-chain precursors (Bs2Δwzm) and mutants with a smooth (S) LPS defective in the core lateral branch (Bs2ΔwadB and Bs2ΔwadD). We also investigated mutants in the pyruvate phosphate dikinase (Bs2ΔppdK) and phosphoenolpyruvate carboxykinase (Bs2ΔpckA) genes encoding enzymes bridging phosphoenolpyruvate and the tricarboxylic acid cycle. When tested in the OIE mouse model at the recommended R or S vaccine doses (108 and 105 CFU, respectively), CFU/spleen of all LPS mutants were reduced with respect to the wild type and decreased faster for the R than for the S mutants. At those doses, protection against B. suis was similar for Bs2ΔwbkF, Bs2Δwzm, Bs2ΔwadB and the Rev1 control (105 CFU). As described before for B. abortus, B. suis biovar 2 carried a disabled pckA so that a double mutant Bs2ΔppdKΔpckA had the same metabolic phenotype as Bs2ΔppdK and ppdK mutation was enough to generate attenuation. At 105 CFU, Bs2ΔppdK also conferred the same protection as Rev1. As compared to other B. suis vaccine candidates described before, the mutants described here simultaneously carry irreversible deletions easy to identify as vaccine markers, lack antibiotic-resistance markers and were obtained in a non-zoonotic background. Since R vaccines should not elicit antibodies to the S-LPS and wzm mutants carry immunogenic O-chain precursors and did not improve Bs2ΔwbkF, the latter seems a better R vaccine candidate than Bs2Δwzm. However, taking into account that all R vaccines interfere in ELISA and other widely used assays, whether Bs2ΔwbkF is advantageous over Bs2ΔwadB or Bs2ΔppdK requires experiments in the natural host.
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Additional file 4 of Development of attenuated live vaccine candidates against Swine Brucellosis in a non-zoonotic B. suis biovar 2 background
2020Co-Authors: Beatriz Aragón-aranda, María Jesús De Miguel, Leticia Lázaro-antón, Miriam Salvador-bescós, Amaia Zúñiga-ripa, Ignacio Moriyón, Maite Iriarte, Pilar M. Muñoz, Raquel Conde-ÁlvarezAbstract:Additional file 4. Oligonucleotide sequences used for Bs2Δwzmand Bs2ΔwbkFmutant constructions.
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phylogeography and epidemiology of brucella suis biovar 2 in wildlife and domestic Swine
Veterinary Microbiology, 2019Co-Authors: Pilar M. Muñoz, María Jesús De Miguel, Virginie Mick, Lorena Sacchini, Anna Janowicz, Moulayali Cherfa, Celia Rodriguez Nevado, Guillaume Girault, Sara Andresbarranco, Maryne JayAbstract:Swine Brucellosis due to Brucella suis biovar 2 (bv2) is enzootic in wild boar and hare in continental Europe and may cause major economic losses to the pig industry, mainly in free-ranged pig farms. The high nucleotide identity found among the B. suis biovar 2 isolates has long hindered the full understanding of the epidemiology and the phylogeography of the disease. Here, we used multilocus variable-number tandem-repeat (VNTR) analysis (MLVA) and whole-genome analysis to identify single-nucleotide polymorphisms (SNPs) in order to gain insights from the largest B. suis bv2 dataset analyzed so far composed of domestic pigs and wildlife isolates collected throughout Europe since the 1970s. We found four major clades with a specific phylogeographic pattern. The Iberian clade contains isolates exclusively from the Iberian Peninsula. The Central European clade includes most isolates from France, Northern Italy, Switzerland and an important proportion of those of Northern Spain. The Eastern European clade clustered isolates from Croatia and Hungary mainly but also from areas of France, Germany, Italy and Poland. Finally, a separated Sardinian clade grouped three isolates from this island. At fine scale, MLVA demonstrated an endemic status of the infection in Europe and it allowed tracking a large outbreak formed by different farms from Spain linked to the same infection source. The whole genome SNP analysis showed that the strains form genetically distinct clades, shared between wild boar and pigs, in agreement with the MLVA clades. Interestingly, all hare isolates clustered together within two groups composed exclusively of wildlife isolates. Our results support the hypothesis that maintenance and spread of B. suis bv2 in Europe is a dynamic process linked to the natural expansion of wild boar as the main wild reservoir of the infection, while spread over long distances is found largely dependent on anthropogenic activities.
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Gene expression changes in spleens of the wildlife reservoir species, Eurasian wild boar (Sus scrofa), naturally infected with Brucella suis biovar 2
'Elsevier BV', 2017Co-Authors: Galindo, Ruth C., María Jesús De Miguel, Blasco, José M., Muñoz, Pilar M., Marín, Clara M., Gortázar Christian, Jose De La FuenteAbstract:Brucella suis is responsible for Swine Brucellosis worldwide. Of the five different B. suis biovars (bv.), bv. 2 appears restricted to Europe where it is frequently isolated from wild boar and hares, can infect pigs and can cause human Brucellosis. In this study, the differential gene expression profile was characterized in spleens of Eurasian wild boar naturally infected with B. suis bv. 2. Of the 20,201 genes analyzed in the microarray, 633 and 1,373 were significantly (fold change > 1.8; P < 0.01) upregulated and downregulated, respectively, in infected wild boar. The analysis was focused on genes that were over represented after conditional test for biological process gene ontology. Upregulated genes suggested that B. suis bv. 2 infection induced cell maturation, migration and/or proliferation in infected animals. The genes downregulated in infected wild boar impaired the activity of several important cellular metabolic pathways such as metabolism, cytoskeleton organization and biogenesis, immune response and lysosomal function and vesicle-mediated transport. In addition, the response to stress, sperm fertility, muscle development and apoptosis seemed to be also impaired in infected animals. These results suggested that B. suis bv. 2 may use strategies similar to other smooth brucellae to facilitate intracellular multiplication and the development of chronic infections. To our knowledge, this is the first report of the analysis of gene expression profile in hosts infected with B. suis bv. 2, which is important to understand the molecular mechanisms at the host-pathogen interface in the main reservoir species with possible implications in the zoonotic cycle of the pathogen.This work was supported by the Grupo Santander and Fundación Marcelino Botín, Spain (Project Control of Tuberculosis in Wildlife), Ministerio de Educación y Ciencia (MEC; Project AGL2005-07401) and FEDER, Spain. R.C. Galindo was funded by MEC, Spain.Peer Reviewe
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Assessment of performance of selected serological tests for diagnosing Brucellosis in pigs
Veterinary immunology and immunopathology, 2012Co-Authors: Pilar M. Muñoz, María Jesús De Miguel, José M. Blasco, Bas Engel, Clara Marin, Lucía Dieste, Raúl C. Mainar-jaimeAbstract:Abstract Swine Brucellosis due to Brucella suis is considered an emerging zoonotic disease whose control is based on serological testing and the subsequent culling of seropositive animals or the full depopulation of affected flocks. Here we assessed the performance of several serological tests (Rose Bengal Test [RBT], indirect ELISA [i-ELISA], blocking ELISA [b-ELISA], and two competitive ELISAs [c-ELISA]) for diagnosing Swine Brucellosis caused by B. suis biovar 2. Both frequentistic and Bayesian statistical inference were used. A frequentistic analysis, using sera from known gold standard (GS) populations ( i.e. , from truly infected or Brucellosis free animals), resulted in maximum (100%) diagnostic sensitivity (Se) and specificity (Sp) in the RBT, i-ELISA and b-ELISA tests. However, c-ELISAs resulted in lower diagnostic Se (ranging from 68.5% to 92.6%, according to the different cut-offs selected). A Bayesian analysis of tests yielding the best diagnostic performance with GS sera (RBT, i-ELISA and b-ELISA), but using a large collection of field sera, resulted in similar Se among tests but markedly lower (≈80%) than that resulting from the frequentistic analysis using the GS serum populations. By contrast, the estimated Sp in the Bayesian analysis was only slightly lower than 100%, thus similar to that obtained frequentistically. Our results show that adequate diagnostic tests for Brucellosis in Swine are available, but also emphasize the need for more extensive validation studies before applying these tests under field conditions.
Ricardo Dias - One of the best experts on this subject based on the ideXlab platform.
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Evolution and genome specialization of Brucella suis biovar 2 Iberian lineages.
BMC genomics, 2017Co-Authors: Ana C. Ferreira, Rogério Tenreiro, Ricardo DiasAbstract:Swine Brucellosis caused by B. suis biovar 2 is an emergent disease in domestic pigs in Europe. The emergence of this pathogen has been linked to the increase of extensive pig farms and the high density of infected wild boars (Sus scrofa). In Portugal and Spain, the majority of strains share specific molecular characteristics, which allowed establishing an Iberian clonal lineage. However, several strains isolated from wild boars in the North-East region of Spain are similar to strains isolated in different Central European countries. Comparative analysis of five newly fully sequenced B. suis biovar 2 strains belonging to the main circulating clones in Iberian Peninsula, with publicly available Brucella spp. genomes, revealed that strains from Iberian clonal lineage share 74% similarity with those reference genomes. Besides the 210 kb translocation event present in all biovar 2 strains, an inversion with 944 kb was presented in chromosome I of strains from the Iberian clone. At left and right crossover points, the inversion disrupted a TRAP dicarboxylate transporter, DctM subunit, and an integral membrane protein TerC. The gene dctM is well conserved in Brucella spp. except in strains from the Iberian clonal lineage. Intraspecies comparative analysis also exposed a number of biovar-, haplotype- and strain-specific insertion-deletion (INDELs) events and single nucleotide polymorphisms (SNPs) that could explain differences in virulence and host specificities. Most discriminative mutations were associated to membrane related molecules (29%) and enzymes involved in catabolism processes (20%). Molecular identification of both B. suis biovar 2 clonal lineages could be easily achieved using the target-PCR procedures established in this work for the evaluated INDELs. Whole-genome analyses supports that the B. suis biovar 2 Iberian clonal lineage evolved from the Central-European lineage and suggests that the genomic specialization of this pathogen in the Iberian Peninsula is independent of a specific genomic event(s), but instead driven by allopatric speciation, resulting in the establishment of a new ecovar.
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MLVA-16 typing of Brucella suis biovar 2 strains circulating in Europe.
Veterinary microbiology, 2017Co-Authors: Ana C. Ferreira, Ricardo Dias, Rogério TenreiroAbstract:Swine Brucellosis due to Brucella suis biovar 2 is an emerging disease in Europe, associated with increase of extensive Swine farms and high density of infected wild boars. Since knowledge of predominant circulating strains is a prerequisite for any epidemiological study, accurate molecular typing procedures were applied to a collection of 176 B. suis isolates. By using suis-ladder multiplex PCR and PCR-RFLP analysis of omp2a, omp2b and omp31 genes, five haplotypes were identified among 160 biovar 2 isolates, with haplotypes 2d and 2e restricted to Portugal and Spain and haplotypes 2a, 2b and 2c widespread in Europe (except Portugal). MLVA based on 16 genetic markers (MLVA-16) revealed 126 genotypes, with 101 singletons, and grouped biovar 2 isolates in two clusters according to their geographic origins and haplotypes, defining the Iberian (Portugal and Spain) and the Central-European clonal lineages. In order to get insights on the evolutionary associations between B. suis lineages and their host species, an extended analysis was performed using a subset of 11 markers and publicly available data for 350 additional strains. This MLVA-11 analysis revealed a high genetic divergence amongst the 526 B. suis strains based on their hosts and highlighted the close relationship between strains from Swine, wild boars and hares. Beyond corroborating the existence of Iberian and Central European biovar 2 clonal lineages and pointing to the evolution of biovar 2 Iberian clonal lineage from Central-European one by an allopatric speciation event, an ongoing colonization of Iberian Peninsula with specific MLVA-11 genotypes is also highlighted.
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Evolution and genome specialization of Brucella suis biovar 2 Iberian lineages
BMC, 2017Co-Authors: Ana Cristina Ferreira, Rogério Tenreiro, Ricardo DiasAbstract:Abstract Background Swine Brucellosis caused by B. suis biovar 2 is an emergent disease in domestic pigs in Europe. The emergence of this pathogen has been linked to the increase of extensive pig farms and the high density of infected wild boars (Sus scrofa). In Portugal and Spain, the majority of strains share specific molecular characteristics, which allowed establishing an Iberian clonal lineage. However, several strains isolated from wild boars in the North-East region of Spain are similar to strains isolated in different Central European countries. Results Comparative analysis of five newly fully sequenced B. suis biovar 2 strains belonging to the main circulating clones in Iberian Peninsula, with publicly available Brucella spp. genomes, revealed that strains from Iberian clonal lineage share 74% similarity with those reference genomes. Besides the 210 kb translocation event present in all biovar 2 strains, an inversion with 944 kb was presented in chromosome I of strains from the Iberian clone. At left and right crossover points, the inversion disrupted a TRAP dicarboxylate transporter, DctM subunit, and an integral membrane protein TerC. The gene dctM is well conserved in Brucella spp. except in strains from the Iberian clonal lineage. Intraspecies comparative analysis also exposed a number of biovar-, haplotype- and strain-specific insertion-deletion (INDELs) events and single nucleotide polymorphisms (SNPs) that could explain differences in virulence and host specificities. Most discriminative mutations were associated to membrane related molecules (29%) and enzymes involved in catabolism processes (20%). Molecular identification of both B. suis biovar 2 clonal lineages could be easily achieved using the target-PCR procedures established in this work for the evaluated INDELs. Conclusion Whole-genome analyses supports that the B. suis biovar 2 Iberian clonal lineage evolved from the Central-European lineage and suggests that the genomic specialization of this pathogen in the Iberian Peninsula is independent of a specific genomic event(s), but instead driven by allopatric speciation, resulting in the establishment of a new ecovar
Rogério Tenreiro - One of the best experts on this subject based on the ideXlab platform.
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Evolution and genome specialization of Brucella suis biovar 2 Iberian lineages.
BMC genomics, 2017Co-Authors: Ana C. Ferreira, Rogério Tenreiro, Ricardo DiasAbstract:Swine Brucellosis caused by B. suis biovar 2 is an emergent disease in domestic pigs in Europe. The emergence of this pathogen has been linked to the increase of extensive pig farms and the high density of infected wild boars (Sus scrofa). In Portugal and Spain, the majority of strains share specific molecular characteristics, which allowed establishing an Iberian clonal lineage. However, several strains isolated from wild boars in the North-East region of Spain are similar to strains isolated in different Central European countries. Comparative analysis of five newly fully sequenced B. suis biovar 2 strains belonging to the main circulating clones in Iberian Peninsula, with publicly available Brucella spp. genomes, revealed that strains from Iberian clonal lineage share 74% similarity with those reference genomes. Besides the 210 kb translocation event present in all biovar 2 strains, an inversion with 944 kb was presented in chromosome I of strains from the Iberian clone. At left and right crossover points, the inversion disrupted a TRAP dicarboxylate transporter, DctM subunit, and an integral membrane protein TerC. The gene dctM is well conserved in Brucella spp. except in strains from the Iberian clonal lineage. Intraspecies comparative analysis also exposed a number of biovar-, haplotype- and strain-specific insertion-deletion (INDELs) events and single nucleotide polymorphisms (SNPs) that could explain differences in virulence and host specificities. Most discriminative mutations were associated to membrane related molecules (29%) and enzymes involved in catabolism processes (20%). Molecular identification of both B. suis biovar 2 clonal lineages could be easily achieved using the target-PCR procedures established in this work for the evaluated INDELs. Whole-genome analyses supports that the B. suis biovar 2 Iberian clonal lineage evolved from the Central-European lineage and suggests that the genomic specialization of this pathogen in the Iberian Peninsula is independent of a specific genomic event(s), but instead driven by allopatric speciation, resulting in the establishment of a new ecovar.
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MLVA-16 typing of Brucella suis biovar 2 strains circulating in Europe.
Veterinary microbiology, 2017Co-Authors: Ana C. Ferreira, Ricardo Dias, Rogério TenreiroAbstract:Swine Brucellosis due to Brucella suis biovar 2 is an emerging disease in Europe, associated with increase of extensive Swine farms and high density of infected wild boars. Since knowledge of predominant circulating strains is a prerequisite for any epidemiological study, accurate molecular typing procedures were applied to a collection of 176 B. suis isolates. By using suis-ladder multiplex PCR and PCR-RFLP analysis of omp2a, omp2b and omp31 genes, five haplotypes were identified among 160 biovar 2 isolates, with haplotypes 2d and 2e restricted to Portugal and Spain and haplotypes 2a, 2b and 2c widespread in Europe (except Portugal). MLVA based on 16 genetic markers (MLVA-16) revealed 126 genotypes, with 101 singletons, and grouped biovar 2 isolates in two clusters according to their geographic origins and haplotypes, defining the Iberian (Portugal and Spain) and the Central-European clonal lineages. In order to get insights on the evolutionary associations between B. suis lineages and their host species, an extended analysis was performed using a subset of 11 markers and publicly available data for 350 additional strains. This MLVA-11 analysis revealed a high genetic divergence amongst the 526 B. suis strains based on their hosts and highlighted the close relationship between strains from Swine, wild boars and hares. Beyond corroborating the existence of Iberian and Central European biovar 2 clonal lineages and pointing to the evolution of biovar 2 Iberian clonal lineage from Central-European one by an allopatric speciation event, an ongoing colonization of Iberian Peninsula with specific MLVA-11 genotypes is also highlighted.
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Evolution and genome specialization of Brucella suis biovar 2 Iberian lineages
BMC, 2017Co-Authors: Ana Cristina Ferreira, Rogério Tenreiro, Ricardo DiasAbstract:Abstract Background Swine Brucellosis caused by B. suis biovar 2 is an emergent disease in domestic pigs in Europe. The emergence of this pathogen has been linked to the increase of extensive pig farms and the high density of infected wild boars (Sus scrofa). In Portugal and Spain, the majority of strains share specific molecular characteristics, which allowed establishing an Iberian clonal lineage. However, several strains isolated from wild boars in the North-East region of Spain are similar to strains isolated in different Central European countries. Results Comparative analysis of five newly fully sequenced B. suis biovar 2 strains belonging to the main circulating clones in Iberian Peninsula, with publicly available Brucella spp. genomes, revealed that strains from Iberian clonal lineage share 74% similarity with those reference genomes. Besides the 210 kb translocation event present in all biovar 2 strains, an inversion with 944 kb was presented in chromosome I of strains from the Iberian clone. At left and right crossover points, the inversion disrupted a TRAP dicarboxylate transporter, DctM subunit, and an integral membrane protein TerC. The gene dctM is well conserved in Brucella spp. except in strains from the Iberian clonal lineage. Intraspecies comparative analysis also exposed a number of biovar-, haplotype- and strain-specific insertion-deletion (INDELs) events and single nucleotide polymorphisms (SNPs) that could explain differences in virulence and host specificities. Most discriminative mutations were associated to membrane related molecules (29%) and enzymes involved in catabolism processes (20%). Molecular identification of both B. suis biovar 2 clonal lineages could be easily achieved using the target-PCR procedures established in this work for the evaluated INDELs. Conclusion Whole-genome analyses supports that the B. suis biovar 2 Iberian clonal lineage evolved from the Central-European lineage and suggests that the genomic specialization of this pathogen in the Iberian Peninsula is independent of a specific genomic event(s), but instead driven by allopatric speciation, resulting in the establishment of a new ecovar
