254 research outputs found

    Bacteriophage-encoded depolymerases: their diversity and biotechnological applications

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    Bacteriophages (phages), natural enemies of bacteria, can encode enzymes able to degrade polymeric substances. These substances can be found in the bacterial cell surface, such as polysaccharides, or are produced by bacteria when they are living in biofilm communities, the most common bacterial lifestyle. Consequently, phages with depolymerase activity have a facilitated access to the host receptors, by degrading the capsular polysaccharides, and are believed to have a better performance against bacterial biofilms, since the degradation of extracellular polymeric substances by depolymerases might facilitate the access of phages to the cells within different biofilm layers. Since the diversity of phage depolymerases is not yet fully explored, this is the first review gathering information about all the depolymerases encoded by fully sequenced phages. Overall, in this study, 160 putative depolymerases, including sialidases, levanases, xylosidases, dextranases, hyaluronidases, peptidases as well as pectate/pectin lyases, were found in 143 phages (43 Myoviridae, 47 Siphoviridae, 37 Podoviridae, and 16 unclassified) infecting 24 genera of bacteria. We further provide information about the main applications of phage depolymerases, which can comprise areas as diverse as medical, chemical, or food-processing industry.DPP acknowledges the financial support from the Portuguese Foundation for Science and Technology (FCT) through the grant SFRH/BD/76440/2011. SS is an FCT investigator (IF/01413/2013). The authors also thank FCT for the Strategic Project of the UID/BIO/04469/2013 unit, FCT and European Union funds (FEDER/COMPETE) for the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER027462)

    Use of beneficial bacteria and their secondary metabolites to control grapevine pathogen diseases

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    Grapevine is one of the most important economic crops yielding berries, wine products as well as derivates. However, due to the large array of pathogens inducing diseases on this plant, considerable amounts of pesticides—with possible negative impact on the environment and health—have been used and are currently used in viticulture. To avoid negative impacts of such products and to ensure product quality, a substantial fraction of pesticides needs to be replaced in the near future. One solution can be related to the use of beneficial bacteria inhabiting the rhizo- and/or the endosphere of plants. These biocontrol bacteria and their secondary metabolites can reduce directly or indirectly pathogen diseases by affecting pathogen performance by antibiosis, competition for niches and nutrients, interference with pathogen signaling or by stimulation of host plant defenses. Due to the large demand for biocontrol of grapevine diseases, such biopesticides, their modes of actions and putative consequences of their uses need to be described. Moreover, the current knowledge on new strains from the rhizo- and endosphere and their metabolites that can be used on grapevine plants to counteract pathogen attack needs to be discussed. This is in particular with regard to the control of root rot, grey mould, trunk diseases, powdery and downy mildews, pierce’s disease, grapevine yellows as well as crown gall. Future prospects on specific beneficial microbes and their secondary metabolites that can be used as elicitors of plant defenses and/or as biocontrol agents with potential use in a more sustainable viticulture will be further discussed

    Comparison Between Maximum Inspiratory Pressure Measured By A Digital Manometer And By An Electronic Inspiratory Muscle Training Device

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    Aims: To compare maximum inspiratory pressure (MIP) measured by a digital manometer and by an inspiratory muscle training (IMT) device and to evaluate hemodynamic changes after measurements. Methods: The sample included male and female individuals older than 18 years admitted to an intensive care unit who were hemodynamically stable, not being treated with vasoactive drugs or sedated, intubated or tracheostomized, and who were in the process of being weaned from mechanical ventilation. MIP was measured by both devices on three different occasions, with an occlusion time of 20 seconds and a 5-minute interval between measurements. The following parameters were assessed: respiratory rate, mean arterial pressure, and respiratory rate before and after each measurement by each device. The statistical analysis was made in the Statistical Analysis System and the R Project for Statistical Computing V. 3.1.2 softwares, using the ANOVA and the Wilcoxon tests. Results: Fifty-eight patients were included in the study. The mean value obtained for MIP was -46.22 centimeters of water (cmH(2)O) in the digital manometer and -13.15 cmH(2)O (p<0.001) in the IMT device. Heart rate showed a significant increase (p<0.0001) both before and after all measurements in both devices. Mean arterial pressure showed a statistically significant difference only before and after the first measurement by the digital manometer and before and after the second measurement by the IMT device (p<0.001). The respiratory rate oscillated significantly before and after the three measurements by both devices (p<0.0001). The hemodynamic parameters remained within reference values after MIP measurements. Conclusions: The digital manometer recorded a higher MIP than that measured by the IMT device. The hemodynamic parameter values oscillated in both devices, but they remained within the normal range and were not clinically significant.2

    Comparison Between Maximum Inspiratory Pressure Measured By A Digital Manometer And By An Electronic Inspiratory Muscle Training Device

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    To compare maximum inspiratory pressure (MIP) measured by a digital manometer and by an inspiratory muscle training (IMT) device and to evaluate hemodynamic changes after measurements. Methods: The sample included male and female individuals older than 18 years admitted to an intensive care unit who were hemodynamically stable, not being treated with vasoactive drugs or sedated, intubated or tracheostomized, and who were in the process of being weaned from mechanical ventilation. MIP was measured by both devices on three different occasions, with an occlusion time of 20 seconds and a 5-minute interval between measurements. The following parameters were assessed: respiratory rate, mean arterial pressure, and respiratory rate before and after each measurement by each device. The statistical analysis was made in the Statistical Analysis System and the R Project for Statistical Computing V. 3.1.2 softwares, using the ANOVA and the Wilcoxon tests. Results: Fifty-eight patients were included in the study. The mean value obtained for MIP was -46.22 centimeters of water (cmH(2)O) in the digital manometer and -13.15 cmH(2)O (p<0.001) in the IMT device. Heart rate showed a significant increase (p<0.0001) both before and after all measurements in both devices. Mean arterial pressure showed a statistically significant difference only before and after the first measurement by the digital manometer and before and after the second measurement by the IMT device (p<0.001). The respiratory rate oscillated significantly before and after the three measurements by both devices (p<0.0001). The hemodynamic parameters remained within reference values after MIP measurements. Conclusions: The digital manometer recorded a higher MIP than that measured by the IMT device. The hemodynamic parameter values oscillated in both devices, but they remained within the normal range and were not clinically significant.2

    Novel phages of healthy skin metaviromes from South Africa

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    Recent skin metagenomic studies have investigated the harbored viral diversity and its possible influence on healthy skin microbial populations, and tried to establish global patterns of skin-phage evolution. However, the detail associated with the phages that potentially play a role in skin health has not been investigated. While skin metagenome and -metavirome studies have indicated that the skin virome is highly site specific and shows marked interpersonal variation, they have not assessed the presence/absence of individual phages. Here, we took a semi-culture independent approach (metaviromic) to better understand the composition of phage communities on skin from South African study participants. Our data set adds over 130 new phage species of the skin to existing databases. We demonstrated that identical phages were present on different individuals and in different body sites, and we conducted a detailed analysis of the structural organization of these phages. We further found that a bacteriophage related to the Staphylococcus capitis phage Stb20 may be a common skin commensal virus potentially regulating its host and its activities on the ski

    Ossifying Fibroma of Non-odontogenic Origin: A Fibro-osseous Lesion in the Craniofacial Skeleton to be (Re-)considered

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    In the cranio-facial skeleton, a heterogeneous group of well characterized fibro-osseous lesions can be distinguished. Whereas fibrous dysplasia can affect any skeletal bone, ossifying fibroma and cemento-osseous dysplasia exclusively develop in the cranio-facial region, with most subtypes restricted to the tooth bearing areas of the jaws. Herein we present a series of 20 fibro-osseous lesions that developed mostly in the frontal bone and in the mandible, presenting as expansile intramedullary tumors with a unique histologic appearance and an indolent clinical course. We provide evidence that these tumors are distinct from the categories included in the WHO classification and are therefore currently unclassifiable. The definition of cemento-ossifying fibroma as an odontogenic neoplasm developing only in close proximity to teeth should be re-considered and incorporate also extragnathic lesions as shown here

    Student Experiences of Sexual Violence as Targets and Bystanders—a Qualitative Investigation in a Public University in Guatemala

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    Bystander behaviour in sexual violence has been investigated widely in the Global North, and especially in the US context. However, there has been a call for qualitative approaches to increase understanding of sexual violence and bystander behaviour in a wider range of countries. In the present study, we conducted focus group research to investigate sexual violence in the only public university in Guatemala, Central America. In total, 18 students (5 men) participated in one of six online focus group sessions. We employed an inductive thematic analysis, and constructed four main themes: Forms, dynamics, and consequences violence to the targets and the bystanders; Barriers to bystander action; Facilitators to bystander action; and Past bystander intervention actions. We discuss the results with a reference to the context in Guatemala, and suggest intervention approaches based for the future

    Oral acantholytic squamous cell carcinoma shares clinical and histological features with angiosarcoma

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    <p>Abstract</p> <p>Background</p> <p>acantholytic squamous cell carcinomas (ASCC) and intraoral angiosarcoma share similar histopathological features. Aim of this study was to find marker for a clear distinction.</p> <p>Methods</p> <p>Four oral acantholytic squamous cell carcinomas and one intraoral angiosarcoma are used to compare the eruptive intraoral growth-pattern, age-peak, unfavourable prognosis and slit-like intratumorous spaces in common histological staining as identical clinical and histopathological features. Immunohistochemical staining for pancytokeratin, cytokeratin, collagen type IV, γ2-chain of laminin-5, endothelial differentiation marker CD31 and CD34, F VIII-associated antigen, Ki 67-antigen, β-catenin, E-cadherin, α-smooth-muscle-actin and Fli-1 were done.</p> <p>Results</p> <p>Cytokeratin-immunoreactive cells can be identified in both lesions. The large vascularization of ASCC complicates the interpretation of vascular differential markers being characteristic for angiosarcoma. Loss of cell-cell-adhesion, monitored by loss of E-cadherin and β-catenin membrane-staining, are indetified as reasons for massive expression of invasion-factor ln-5 in ASCC and considered responsible for unfavourable prognosis of ASCC. Expression of Fli-1 in angiosarcoma and cellular immunoreaction for ln-5 in ASCC are worked out as distinguishing features of both entities.</p> <p>Conclusion</p> <p>Fli-1 in angiosarcoma and ln-5 in ASCC are distinguishing features.</p

    Barriers to Bystander Action in Sexual Violence in Guatemala: The Role of Rape Myth Acceptance

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    Understanding bystander barriers in sexual violence is an important step towards increasing knowledge on how to teach people to intervene safely. Although bystander behaviour has been widely studied especially in the US context, there is a dearth of research outside the Global North. In this study, we report results of an investigation in Guatemala, a Central American country with high levels of gender-based violence. In an online study, 1009 University students and staff completed adapted questionnaires on rape myth acceptance and bystander barriers. Correlational and regression analyses demonstrated that the rape myths ‘She asked for it’ and ‘It wasn’t rape’ were important predictors of multiple barriers (i.e., Failure to notice, Failure to identify situation as high risk, Failure to take intervention responsibility, Failure to intervene due to a skills deficit and Failure to intervene due to audience inhibition). We discuss the results in the context of Guatemalan culture and society
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