Guía técnica del cultivo de coco

En la presente guía el lector podrá encontrar información útil, relacionada con las generalidades del cultivo, los requerimientos de clima y suelo, zonas aptas en el país, los múltiples usos del producto, información básica para el establecimiento y manejo de la plantación, principales plagas y enfermedades que le afectan, aspectos de cosecha, información financiera, mercado y agroindustria, en resumen un documento de utilidad práctica para los productores y técnico

M1T1 group A streptococcal pili promote epithelial colonization but diminish systemic virulence through neutrophil extracellular entrapment

Group A Streptococcus is a leading human pathogen associated with a diverse array of mucosal and systemic infections. Cell wall anchored pili were recently described in several species of pathogenic streptococci, and in the case of GAS, these surface appendages were demonstrated to facilitate epithelial cell adherence. Here we use targeted mutagenesis to evaluate the contribution of pilus expression to virulence of the globally disseminated M1T1 GAS clone, the leading agent of both GAS pharyngitis and severe invasive infections. We confirm that pilus expression promotes GAS adherence to pharyngeal cells, keratinocytes, and skin. However, in contrast to findings reported for group B streptococcal and pneumococcal pili, we observe that pilus expression reduces GAS virulence in murine models of necrotizing fasciitis, pneumonia and sepsis, while decreasing GAS survival in human blood. Further analysis indicated the systemic virulence attenuation associated with pilus expression was not related to differences in phagocytic uptake, complement deposition or cathelicidin antimicrobial peptide sensitivity. Rather, GAS pili were found to induce neutrophil IL-8 production, promote neutrophil transcytosis of endothelial cells, and increase neutrophil release of DNA-based extracellular traps, ultimately promoting GAS entrapment and killing within these structures

Environmental Acidification Drives S. pyogenes Pilus Expression and Microcolony Formation on Epithelial Cells in a FCT-Dependent Manner

Group A Streptococcus (GAS, Streptococcus pyogenes) is a Gram-positive human pathogen responsible for a diverse variety of diseases, including pharyngitis, skin infections, invasive necrotizing fasciitis and autoimmune sequelae. We have recently shown that GAS cell adhesion and biofilm formation is associated with the presence of pili on the surface of these bacteria. GAS pilus proteins are encoded in the FCT (Fibronectin- Collagen-T antigen) genomic region, of which nine different variants have been identified so far. In the present study we undertook a global analysis of GAS isolates representing the majority of FCT-variants to investigate the effect of environmental growth conditions on their capacity to form multicellular communities. For FCT-types 2, 3, 5 and 6 and a subset of FCT-4 strains, we observed that acidification resulting from fermentative sugar metabolism leads to an increased ability of the bacteria to form biofilm on abiotic surfaces and microcolonies on epithelial cells. The higher biofilm forming capacity at low environmental pH was directly associated with an enhanced expression of the genes encoding the pilus components and of their transcription regulators. The data indicate that environmental pH affects the expression of most pilus types and thereby the formation of multicellular cell-adhering communities that assist the initial steps of GAS infection

Child protection and welfare systems in Ireland: continuities and discontinuities of the present

This chapter provides an overview of the Irish child protection and welfare system, and examines continuities and discontinuities between the past and the present. 2012 is chosen as a pivotal change moment around which to critically examine current developments. This year is chosen due to seminal change events which occurred such as a referendum on the rights of the child and the publication of a report that led to the blueprint for the establishment of an independent Child and Family Agency in Ireland. We chart existing histories of child welfare and comment on significant trends and developments. Against the backdrop of this history, we discuss whether, almost 50 years on, the context, appetite for and investment in change, is to be realised in the biggest structural change to children’s services since the development of Community Care under the Health Act in 1970. In undertaking this analysis, we examine five themes: the establishment of a new Child and Family Agency (Tusla); Signs of Safety adopted as a new national child protection approach; changing trends in child welfare as demonstrated by recent statistics, retention rates for social workers in child protection; and dealing with retrospective child abuse disclosures, institutional abuse and Church-State relations