17 research outputs found

    Analysing nonsynonymous mutations between two Mycobacterium bovis strains with contrasting pathogenic profiles.

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    Mycobacterium bovis (M. bovis) is the causative agent of bovine tuberculosis, a chronic infectious disease that can affect cattle, other domesticated species, wild animals and humans. This disease produces important economic losses worldwide. Two M. bovis strains (04-303 and 534) have been isolated in Argentina. Whereas the 04-303 strain was isolated from a wild boar, the 534 strain was obtained from cattle. In a previous study, six weeks after infection, the 04-303 strain induced 100% mortality in mice. By contrast, mice infected with the 534 strain survived, with limited tissue damage, after four months. In this study we compared all predictive proteins encoded in both M. bovis genomes. The comparative analysis revealed 141 polymorphic proteins between both strains. From these proteins, nine virulence proteins showed polymorphisms in 04-303, whereas five did it in the 534 strain. Remarkably, both strains contained a high level of polymorphism in proteins related to phthiocerol dimycocerosate (PDIM) synthesis or transport. Further experimental evidence indicated that only mutations in the 534 strain have an impact on PDIM synthesis. The observed reduction in PDIM content in the 534 strain, together with its low capacity to induce phagosome arrest, may be associated with the reported deficiency of this strain to replicate and survive inside bovine macrophages. The findings of this study could contribute to a better understanding of pathogenicity and virulence aspects of M. bovis, which is essential for further studies aiming at developing new vaccines and diagnostic techniques for bovines

    Comparação de genes de virulĂȘncia de duas cepas de Mycobacterium bovis com perfis patogĂȘnicos contrastantes.

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    Microbial Diversity of a Brazilian Coastal Region Influenced by an Upwelling System and Anthropogenic Activity

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    BACKGROUND: Upwelling systems are characterised by an intense primary biomass production in the surface (warmest) water after the outcrop of the bottom (coldest) water, which is rich in nutrients. Although it is known that the microbial assemblage plays an important role in the food chain of marine systems and that the upwelling systems that occur in southwest Brazil drive the complex dynamics of the food chain, little is known about the microbial composition present in this region. METHODOLOGY/PRINCIPAL FINDINGS: We carried out a molecular survey based on SSU rRNA gene from the three domains of the phylogenetic tree of life present in a tropical upwelling region (Arraial do Cabo, Rio de Janeiro, Brazil). The aim was to analyse the horizontal and vertical variations of the microbial composition in two geographically close areas influenced by anthropogenic activity (sewage disposal/port activity) and upwelling phenomena, respectively. A lower estimated diversity of microorganisms of the three domains of the phylogenetic tree of life was found in the water of the area influenced by anthropogenic activity compared to the area influenced by upwelling phenomena. We observed a heterogenic distribution of the relative abundance of taxonomic groups, especially in the Archaea and Eukarya domains. The bacterial community was dominated by Proteobacteria, Cyanobacteria and Bacteroidetes phyla, whereas the microeukaryotic community was dominated by Metazoa, Fungi, Alveolata and Stramenopile. The estimated archaeal diversity was the lowest of the three domains and was dominated by uncharacterised marine Crenarchaeota that were most closely related to Marine Group I. CONCLUSIONS/SIGNIFICANCE: The variety of conditions and the presence of different microbial assemblages indicated that the area of Arraial do Cabo can be used as a model for detailed studies that contemplate the correlation between pollution-indicating parameters and the depletion of microbial diversity in areas close to anthropogenic activity; functional roles and geochemical processes; phylogeny of the uncharacterised diversity; and seasonal variations of the microbial assemblages

    Weight gain and control of endo- and ectoparasites of beef heifers treated with allopathic, herbal and homeopathic drugs

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    The aim of this study was to evaluate the efficacy of herbal, homeopathic and allopathic treatments for parasites in beef heifers during two experimental cycles of 318 and 313 days. Treatments: NC - negative control (untreated); HH - treated with homeopathic preparation Homeo bovis Parasit&#225;rio&#174;; PC - (positive control) - treated with 10% moxidectina&#174; and an acaricide formulation of cypermethrin, chlorpyrifos and piperonyl butoxide&#174;; HF &#8211; treated with homeopathic preparation Fator C&MC&#174;; and FN - treated with neem cake (torta de neem&#174;) and with neem oil (&#243;leo de neem&#174;). Parasite egg count (EPG), horn fly (Haematobia irritans) and tick (Rhipicephalus (Boophilus) microplus) assessment and animal weighting were performed at 28-day intervals. Blood samples were collected at the first cycle to assess the immune response. Horn fly infestation was not affected by any treatment (P>0.05). The mean number of ticks, which was low in both cycles, was lower (P<0.05) in the first cycle in animals that received PC treatment. In both experimental cycles, the mean EPG of the PC-treated animals was lower (P<0.05) than the animals receiving other treatments. Treatments had no effect on the immune response (P>0.05). The animals treated with allopathic drugs were 22 to 30 kg heavier (P<0.05) than untreated animals or animals treated with alternative drugs

    Caracterização da imunogenicidade das proteínas recombinantes Virb9, Virb10 e fator termo inståvel de elongação de peptídeos de Anaplasma marginale em camundongos.

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    Considerando as limitaçÔes dos atuais métodos de controle contra a anaplasmose bovina, o desenvolvimento de uma vacina efetiva se faz necessårio. A partir do advento da anålise genÎmica e proteÎmica, novas proteínas de membrana de Anaplasma marginale foram identificadas como possíveis candidatas a componentes de uma vacina, tais como, VirB9, VirB10 e Fator Termo Instavél de Elongação de Peptídeos (EF-Tu). Embora estas proteínas ainda não estejam bem caracterizadas na membrana de A. marginale, a produção destas na forma recombinante (rVirB 9, rVirB10 e rEF-Tu) tem sido realizada, mas as mesmas ainda não foram exploradas em formulaçÔes vacinais. Neste trabalho, avaliou-se o uso de rVirB9, rVirB10 e rEF-Tu emulsionadas em adjuvante Montanide em camundongos. Nas condiçÔes testadas, verificou-se a indução de forte resposta imune humoral com a produção de IgG1 e IgG2a, sendo que as proporçÔes dos níveis de produção destas subclasses indicam predomínio de IgG1. Entretanto, esplenócitos de animais, que foram injetados com rVirB9 ou rVirB10, produziram interferon-gama acima do limite de detecção do ensaio após estimulação in vitro, sinalizando assim resposta celular específica. Assim, novas avaliaçÔes serão realizadas com a finalidade de modular o perfil de resposta imune obtido em bovinos e avaliar a proteção contra A. marginale

    Analysing nonsynonymous mutations between two Mycobacterium bovis strains with contrasting pathogenic profiles.

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    Mycobacterium bovis (M. bovis) is the causative agent of bovine tuberculosis, a chronic infectious disease that can affect cattle, other domesticated species, wild animals and humans. This disease produces important economic losses worldwide. Two M. bovis strains (04-303 and 534) have been isolated in Argentina. Whereas the 04-303 strain was isolated from a wild boar, the 534 strain was obtained from cattle. In a previous study, six weeks after infection, the 04-303 strain induced 100% mortality in mice. By contrast, mice infected with the 534 strain survived, with limited tissue damage, after four months. In this study we compared all predictive proteins encoded in both M. bovis genomes. The comparative analysis revealed 141 polymorphic proteins between both strains. From these proteins, nine virulence proteins showed polymorphisms in 04-303, whereas five did it in the 534 strain. Remarkably, both strains contained a high level of polymorphism in proteins related to phthiocerol dimycocerosate (PDIM) synthesis or transport. Further experimental evidence indicated that only mutations in the 534 strain have an impact on PDIM synthesis. The observed reduction in PDIM content in the 534 strain, together with its low capacity to induce phagosome arrest, may be associated with the reported deficiency of this strain to replicate and survive inside bovine macrophages. The findings of this study could contribute to a better understanding of pathogenicity and virulence aspects of M. bovis, which is essential for further studies aiming at developing new vaccines and diagnostic techniques for bovines.Made available in DSpace on 2019-12-31T00:37:05Z (GMT). No. of bitstreams: 1 Analysingnonsynonymousmutations.pdf: 1959637 bytes, checksum: a532d70ba92eb1bbeb63e139eebcc639 (MD5) Previous issue date: 2019bitstream/item/207981/1/Analysing-nonsynonymous-mutations.pd

    Patterns and Processes of Mycobacterium bovis Evolution Revealed by Phylogenomic Analyses.

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    Mycobacterium bovis is an important animal pathogen worldwide that parasitizes wild and domesticated vertebrate livestock as well as humans. A comparison of the five M. bovis complete genomes from the United Kingdom, South Korea, Brazil, and the United States revealed four novel large-scale structural variations of at least 2,000 bp.Acomparative phylogenomic study including 2,483 core genes of 38 taxa from eight countries showed conflicting phylogenetic signal among sites. By minimizing this effect,we obtained a tree that better agreeswith sampling locality. Results supported a relatively basal position of African strains (all isolated from Homo sapiens), confirming that Africa was an important region for early diversification and that humans were one of the earliest hosts. Selection analyses revealed that functional categories such as ?Lipid transport and metabolism,? ?Cell cycle control, cell division, chromosome partitioning? and ?Cell motility? were significant for the evolution of the group, besides other categories previously described, showing importance of genes associated with virulence and cholesterolmetabolism in the evolution of M. bovis. PE/PPE genes,many ofwhich are known to be associated with virulence, were major targets for large-scale polymorphisms, homologous recombination, and positive selection, evincing for the first time a plethora of evolutionary forces possibly contributing to differential adaptability in M. bovis. By assuming different priors, US strains originated and started to diversify around 150?5,210 ya. By further analyzing the largest set of US genomes to date (76 in total), obtained from 14 host species,we detected that hosts were not clustered in clades (except for a few cases), with some faster-evolving strains being detected, suggesting fast and ongoing reinfections across host species, and therefore, the possibility of new bovine tuberculosis outbreaks.Made available in DSpace on 2017-10-14T10:30:37Z (GMT). No. of bitstreams: 1 PatternsandprocessesofMycobacteriumbovis.pdf: 1310401 bytes, checksum: 1ed4d26cd74941c6bda35146799130d9 (MD5) Previous issue date: 2017-10-13bitstream/item/165055/1/Patterns-and-processes-of-Mycobacterium-bovis.pd
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