RinA controls phage-mediated packaging and transfer of virulence genes in Gram-positive bacteria

Phage-mediated transfer of microbial genetic elements plays a crucial role in bacterial life style and evolution. In this study, we identify the RinA family of phage-encoded proteins as activators required for transcription of the late operon in a large group of temperate staphylococcal phages. RinA binds to a tightly regulated promoter region, situated upstream of the terS gene, that controls expression of the morphogenetic and lysis modules of the phage, activating their transcription. As expected, rinA deletion eliminated formation of functional phage particles and significantly decreased the transfer of phage and pathogenicity island encoded virulence factors. A genetic analysis of the late promoter region showed that a fragment of 272 bp contains both the promoter and the region necessary for activation by RinA. In addition, we demonstrated that RinA is the only phage-encoded protein required for the activation of this promoter region. This region was shown to be divergent among different phages. Consequently, phages with divergent promoter regions carried allelic variants of the RinA protein, which specifically recognize its own promoter sequence. Finally, most Gram-postive bacteria carry bacteriophages encoding RinA homologue proteins. Characterization of several of these proteins demonstrated that control by RinA of the phage-mediated packaging and transfer of virulence factor is a conserved mechanism regulating horizontal gene transfer

Big data en educación II: metodologías adaptativas en el proceso de enseñanza-aprendizaje desde el diagnóstico del estudiante

Fac. de Comercio y TurismoFALSEsubmitte

Staphylococcus aureus Pathogenicity Island DNA Is Packaged in Particles Composed of Phage Proteins▿ †

Staphylococcus aureus pathogenicity islands (SaPIs) have an intimate relationship with temperate staphylococcal phages. During phage growth, SaPIs are induced to replicate and are efficiently encapsidated into special small phage heads commensurate with their size. We have analyzed by amino acid sequencing and mass spectrometry the protein composition of the specific SaPI particles. This has enabled identification of major capsid and tail proteins and a putative portal protein. As expected, all these proteins were phage encoded. Additionally, these analyses suggested the existence of a protein required for the formation of functional phage but not SaPI particles. Mutational analysis demonstrated that the phage proteins identified were involved only in the formation and possibly the function of SaPI or phage particles, having no role in other SaPI or phage functions

The inclusion of rapeseed meal in fattening pig diets, as a partial replacer of soybean meal, alters nutrient digestion, faecal composition and biochemical methane potential from faeces

[EN] The effects of including rapeseed meal (RSM) as an alternative source of vegetable protein in pig diets on animal performance, nutrient digestibility and methane production from faeces was investigated. A total of 96 pigs of 42.4 (±4.04) kg of body weight (BW) were allocated into two dietary treatments (48 animals/treatment). One group was fed a conventional diet (C) and the other with a diet containing RSM (R). The level of RSM in the R diet was 120 g/kg during the growing phase (40 70 kg BW; days 1 34 of study) and 200 g/kg during the finishing phase (70 114 kg BW; days 35 76 of study). Average daily gain (ADG), average daily feed intake and feed conversion ratio were measured throughout the study. During the finishing phase, faeces were collected and analysed for dry matter (DM), organic matter (OM), crude protein (CP), crude fat, fibre fractions, pH, volatile fatty acids and biochemical methane potential (B0). Additionally, the coefficient of total tract apparent digestibility (CTTAD) of nutrients was measured using the acid-insoluble ash method. At slaughter (114 ± 12.2 kg BW), the main carcass and meat quality characteristics were registered and the fatty acid (FA) profile of the subcutaneous fat and muscle was analysed. During the growing phase, R animals showed lower ADG compared with C animals (818 vs. 890 g/d; P<0.05). These differences disappeared during the finishing phase. Faeces from treatment R showed a lower B0 compared to those from treatment C (308 vs. 351 mL methane/g OM). Animals from R group showed a lower DM, OM and CP CTTAD than C animals (0.790, 0.826 and 0.729 vs. 0.832, 0.865 and 0.818, respectively; P<0.05) and tended to show lower fibre digestion rates. Consequently, animals from R group showed a higher amount of these components in faeces. However, fat digestion was not affected. No differences were found between treatments on most carcass characteristics. Overall, the inclusion of high levels of RSM in pig diets decreased final BW and nutrient digestibility (except fat) in the finishing phase. However, faeces from animals fed RSM were less degradable, producing less methane per gram of OM.This research was supported by the company Vall Companys Group (Lleida, Spain), the Instituto Valenciano de Investigaciones Agrarias (Valencia) and the Universitat Politecnica de Valencia (Valencia).Torres-Pitarch, A.; Moset, V.; Ferrer Riera, P.; Cambra López, M.; Hernández, P.; Coma, J.; Pascual Amorós, MDLD.... (2014). The inclusion of rapeseed meal in fattening pig diets, as a partial replacer of soybean meal, alters nutrient digestion, faecal composition and biochemical methane potential from faeces. Animal Feed Science and Technology. 198:215-223. https://doi.org/10.1016/j.anifeedsci.2014.09.017S21522319

Relationship between trabecular bone score, bone mineral density and vertebral fractures in patients with axial spondyloarthritis

Abstract Background In patients with axial spondyloarthritis, vertebral fracture risk is elevated and not always correlated with bone mineral density (BMD). Trabecular bone score (TBS) may offer some advantages in the assessment of vertebral fracture risk in these patients. The primary objective of this study was to compare TBS and BMD between axial spondyloarthritis patients depending on their vertebral fracture status. Secondary objectives were to estimate the prevalence of morphometric vertebral fractures, and to explore factors associated with fracture, as well as the interference of syndesmophytes on BMD and TBS. Methods A cross-sectional study was conducted. Data were collected on demographic and clinical characteristics, lab results, imaging findings and treatment. Statistical analysis was performed using SPSS v.13 statistical software. Results Eighty-four patients (60 men and 24 women; mean age of 59 years) were included. Nearly half (47.6%) of them had lumbar syndesmophytes. The rate of morphometric fracture was 11.9%. TBS showed a higher area under the curve (0.89) than total hip, femoral neck and lumbar BMD (0.80, 0.78, and 0.70 respectively) for classifying patients regarding their fracture status. Nonetheless, the differences did not reach statistical significance. Syndesmophytes affected lumbar spine BMD (p < 0.001), but not hip BMD or TBS. Fractures were associated with TBS, total hip BMD, erythrocyte sedimentation rate and C-reactive protein levels. Conclusions We identified decreased TBS and total hip BMD, as well as increased erythrocyte sedimentation rate and C-reactive protein levels as factors associated with morphometric vertebral fractures. Unlike lumbar spine BMD, TBS is not affected by the presence of syndesmophytes

Análisis del tiempo empleado por el alumnado en la realización de exámenes oficiales

En la educación universitaria, una parte de las actividades sometidas a evaluación consiste en una prueba escrita, que tiene una duración limitada. La presente red tiene como fin analizar la afección del tiempo disponible y el tipo de prueba en la calificación el alumno. Para ello, se propone una metodología de recogida y análisis de datos. La metodología propuesta se ha aplicado a seis asignaturas del Grado de Ingeniería Civil y del Máster en Ingeniería de Caminos, Canales y Puertos de la Universidad de Alicante. Los resultados se organizan según herramientas estadísticas (diagramas de dispersión y de cajas). El análisis de resultados indica que en los exámenes tipo test no se ha encontrado correlación entre el tiempo de entrega y la calificación. Sin embargo, en los exámenes de problemas sí que aparece cierto patrón. Esta metodología permite la identificación de calificaciones poco razonables de algunos alumnos, además de ser una herramienta que permite una autocrítica del profesorado para establecer el tiempo disponible para la realización de estas pruebas escritas

Plasma Extracellular Vesicles Play a Role in Immune System Modulation in Minimal Hepatic Encephalopathy

Minimal hepatic encephalopathy (MHE) is associated with changes in the immune system including an increased pro-inflammatory environment and altered differentiation of CD4+ T lymphocytes. The mechanisms remain unknown. Changes in extracellular vesicle (EV) cargo including proteins and miRNAs could play a main role as mediators of immune system changes associated with MHE. The aim was to assess whether plasma EVs from MHE patients played a role in inducing the pro-inflammatory environment and altered differentiation of CD4+ T lymphocyte subtypes in MHE patients. We characterized the miRNA and protein cargo of plasma EVs from 50 cirrhotic patients (27 without and 23 with MHE) and 24 controls. CD4+ T cells from the controls were cultured with plasma EVs from the three groups of study, and the cytokine release and differentiation to CD4+ T-cell subtypes were assessed. Plasma EVs from MHE patients had altered miRNA and protein contents, and were enriched in inflammatory factors compared to the controls and patients without MHE. EVs from MHE patients modulated the expression of pro-inflammatory IL-17, IL-21, and TNF-&alpha; and anti-inflammatory TGF-&beta; in cultured CD4+ T lymphocytes, and increased the proportion of Th follicular and Treg cells and the activation of Th17 cells. In conclusion, plasma EVs could play an important role in the induction of immune changes observed in MHE

RinA controls phage-mediated packaging and transfer of virulence genes in Gram-positive bacteria

Phage-mediated transfer of microbial genetic elements plays a crucial role in bacterial life style and evolution. In this study, we identify the RinA family of phage-encoded proteins as activators required for transcription of the late operon in a large group of temperate staphylococcal phages. RinA binds to a tightly regulated promoter region, situated upstream of the terS gene, that controls expression of the morphogenetic and lysis modules of the phage, activating their transcription. As expected, rinA deletion eliminated formation of functional phage particles and significantly decreased the transfer of phage and pathogenicity island encoded virulence factors. A genetic analysis of the late promoter region showed that a fragment of 272bp contains both the promoter and the region necessary for activation by RinA. In addition, we demonstrated that RinA is the only phage-encoded protein required for the activation of this promoter region. This region was shown to be divergent among different phages. Consequently, phages with divergent promoter regions carried allelic variants of the RinA protein, which specifically recognize its own promoter sequence. Finally, most Gram-postive bacteria carry bacteriophages encoding RinA homologue proteins. Characterization of several of these proteins demonstrated that control by RinA of the phage-mediated packaging and transfer of virulence factor is a conserved mechanism regulating horizontal gene transfer