7 research outputs found

    Genomic analysis and immune response in a murine mastitis model of vB_EcoM-UFV13, a potential biocontrol agent for use in dairy cows

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    Bovine mastitis remains the main cause of economic losses for dairy farmers. Mammary pathogenic Escherichia coli (MPEC) is related to an acute mastitis and its treatment is still based on the use of antibiotics. In the era of antimicrobial resistance (AMR), bacterial viruses (bacteriophages) present as an efficient treatment or prophylactic option. However, this makes it essential that its genetic structure, stability and interaction with the host immune system be thoroughly characterized. The present study analyzed a novel, broad host-range anti-mastitis agent, the T4virus vB-EcoM-UFV13 in genomic terms, and its activity against a MPEC strain in an experimental E. coli-induced mastitis mouse model. 4,975 Single Nucleotide Polymorphisms (SNPs) were assigned between vB-EcoM-UFV13 and E. coli phage T4 genomes with high impact on coding sequences (CDS) (37.60%) for virion proteins. Phylogenetic trees and genome analysis supported a recent infection mix between vB-EcoM-UFV13 and Shigella phage Shfl2. After a viral stability evaluation (e.g pH and temperature), intramammary administration (MOI 10) resulted in a 10-fold reduction in bacterial load. Furthermore, pro-inflammatory cytokines, such as IL-6 and TNF-\u3b1, were observed after viral treatment. This work brings the whole characterization and immune response to vB-EcoM-UFV13, a biocontrol candidate for bovine mastitis

    Diversidade de espécies e variabilidade genética de begomovírus e DNAs satélites infectando plantas não-cultivadas no Brasil e na Espanha

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    Begomoviruses (genus Begomovirus, family Geminiviridae) possess one or two genomic components of circular, single-stranded DNA (ssDNA) encapsidated in geminate icosahedral particles. Most begomoviruses in the New World (NW) are bipartite, while the majority in the Old World (OW) are monopartite and frequently associated with two classes of satellite DNAs: alphasatellites and betasatellites. Alphasatellites have been recently reported in association with bipartite begomoviruses in the NW. Members of the genus Begomovirus are responsible for important crop diseases worldwide. Begomoviruses that infect Ipomoea spp. (family Convolvulaceae), commonly known as "sweepoviruses", have the typical genomic organization of OW monopartite viruses but are phylogenetically distinct from all other species in the genus. Understanding the dynamics and genetic variability of viral populations in non-cultivated hosts is important for the prediction and consequent prevention of new virus diseases in cultivated plants. This work aimed to: (i) assess the diversity of begomoviruses in two non-cultivated hosts widely distributed in Brazil, Sida spp. and Leonurus sibiricus; (ii) determine the genetic structure and variability of begomovirus populations infecting Sida spp. and L. sibiricus; (iii) determine the genetic variability of deltasatellites associated with sweepoviruses infecting Ipomoea indica in Spain and expand the analysis to other geographical areas. For the first two objectives, total DNA was extracted from samples of Sida spp. and L. sibiricus collected in the states of Rio Grande do Sul, Paran√° and Mato Grosso do Sul from 2009 to 2011 and viral genomes were amplified, cloned and sequenced. In Sida spp. the most prevalent virus was Sida micrantha mosaic virus (SiMMV). In addition, three new species were also detected. The vast majority of L. sibiricus samples were infected by Tomato yellow spot virus (ToYSV). Two alphasatellites were found: Euphorbia yellow mosaic alphasatellite in Sida sp. and a new alphasatellite associated with ToYSV in L. sibiricus. Both the SiMMV and ToYSV populations have a high degree of genetic variability. Although a high level of recombination was detected, mutational dynamics was the primary factor of diversification. The results were inconclusive regarding genetic structuration based on geography. For the third objective, DNA was extracted from I. indica samples collected in southern Spain in 2015 and rolling circle amplification (RCA), a technique that allows amplification of circular ssDNA molecules without previous knowledge of nucleotide sequence, was used to clone deltasatellites and two associated sweepoviruses, Sweet potato leaf curl virus (SPLCV) and Sweet potato mosaic virus (SPMV). Deltasatellites showed low sequence variability, no evidence of recombination, and no obvious geographical structuration. Also, a sweepovirus- deltasatellite chimera with a size similar to deltasatellites was detected.Begomov√≠rus (g√™nero Begomovirus, fam√≠lia Geminiviridae) possuem um ou dois componentes gen√īmicos de DNA circular de fita simples, encapsidados em part√≠culas icosa√©dricas geminadas. A maioria dos begomov√≠rus presentes no Novo Mundo (NM) s√£o bissegmentados, enquanto no Velho Mundo (VM) prevalecem os monossegmentados, frequentemente associados a duas classes de DNAs sat√©lites: alfassat√©lites e betassat√©lites. Recentemente, alfassat√©lites foram relatados em associa√ß√£o com begomov√≠rus bissegmentados no NM. Membros do g√™nero Begomovirus s√£o respons√°veis por doen√ßas em culturas economicamente importantes em todo o mundo. Begomov√≠rus que infectam Ipomoea spp. (fam√≠lia Convolvulaceae), comumente denominados "sweepov√≠rus", possuem organiza√ß√£o gen√īmica t√≠pica dos v√≠rus monossegmentados do VM, por√©m s√£o filogeneticamente distintos das demais esp√©cies do g√™nero. O entendimento da din√Ęmica e variabilidade gen√©tica de popula√ß√Ķes virais em plantas n√£o-cultivadas √© importante para auxiliar na previs√£o e preven√ß√£o de doen√ßas em plantas cultivadas. Este trabalho teve como objetivos: (i) estudar a diversidade de esp√©cies de begomov√≠rus em dois hospedeiros n√£o-cultivados amplamente distribu√≠dos no Brasil, Sida spp. e Leonurus sibiricus; (ii) determinar a estrutura e a variabilidade gen√©tica das popula√ß√Ķes de begomov√≠rus em Sida spp. e L. sibiricus; (iii) determinar a variabilidade gen√©tica de deltassat√©lites associados a sweepov√≠rus infectando Ipomoea indica no sul da Espanha, expandindo a an√°lise para outras regi√Ķes geogr√°ficas. Para os dois primeiros objetivos, o DNA total foi extra√≠do de plantas de Sida spp. e L. sibiricus coletadas nos estados do Rio Grande do Sul, Paran√° e Mato Grosso do Sul de 2009 a 2011, e os genomas virais foram amplificados, clonados e sequenciados. A maioria das amostras de Sida spp. estavam infectadas pelo Sida micrantha mosaic virus (SiMMV). Foram encontradas tamb√©m tr√™s novas esp√©cies. A maioria absoluta das amostras de L. sibiricus estavam infectadas pelo Tomato yellow spot virus (ToYSV). Dois alfassat√©lites foram encontrados: Euphorbia yellow mosaic alphasatellite em Sida sp. e um novo alfassat√©lite em L. sibiricus. As popula√ß√Ķes de SiMMV e ToYSV possuem alta variabilidade gen√©tica. Embora um elevado n√≠vel de recombina√ß√£o tenha sido detectado, a din√Ęmica mutacional √© o fator prim√°rio de diversifica√ß√£o. Os resultados s√£o inconclusivos em rela√ß√£o a estrutura√ß√£o baseada em localiza√ß√£o geogr√°fica. Para o terceiro objetivo, DNA foi extra√≠do de plantas de I. indica coletadas no sul da Espanha em 2015, e amplifica√ß√£o por c√≠rculo rolante (RCA), uma t√©cnica que leva a amplifica√ß√£o de mol√©culas de ssDNA circulares sem o conhecimento pr√©vio da sequ√™ncia nucleot√≠dica, foi usada para clonar os deltassat√©lites e seus sweepov√≠rus associados, Sweet potato leaf curl virus (SPLCV) e Sweet potato mosaic virus (SPMV). Deltassat√©lites apresentaram baixa variabilidade de sequ√™ncia, aus√™ncia de recombina√ß√£o e de estrutura√ß√£o geogr√°fica. Al√©m disso, uma quimera sweepov√≠rus- sat√©lite com um tamanho similar ao dos deltassat√©lites foi detectada.Conselho Nacional de Desenvolvimento Cient√≠fico e Tecnol√≥gic