Large-Scale Screening of a Targeted Enterococcus faecalis Mutant Library Identifies Envelope Fitness Factors

Spread of antibiotic resistance among bacteria responsible for nosocomial and community-acquired infections urges for novel therapeutic or prophylactic targets and for innovative pathogen-specific antibacterial compounds. Major challenges are posed by opportunistic pathogens belonging to the low GC% Gram-positive bacteria. Among those, Enterococcus faecalis is a leading cause of hospital-acquired infections associated with life-threatening issues and increased hospital costs. To better understand the molecular properties of enterococci that may be required for virulence, and that may explain the emergence of these bacteria in nosocomial infections, we performed the first large-scale functional analysis of E. faecalis V583, the first vancomycin-resistant isolate from a human bloodstream infection. E. faecalis V583 is within the high-risk clonal complex 2 group, which comprises mostly isolates derived from hospital infections worldwide. We conducted broad-range screenings of candidate genes likely involved in host adaptation (e.g., colonization and/or virulence). For this purpose, a library was constructed of targeted insertion mutations in 177 genes encoding putative surface or stress-response factors. Individual mutants were subsequently tested for their i) resistance to oxidative stress, ii) antibiotic resistance, iii) resistance to opsonophagocytosis, iv) adherence to the human colon carcinoma Caco-2 epithelial cells and v) virulence in a surrogate insect model. Our results identified a number of factors that are involved in the interaction between enterococci and their host environments. Their predicted functions highlight the importance of cell envelope glycopolymers in E. faecalis host adaptation. This study provides a valuable genetic database for understanding the steps leading E. faecalis to opportunistic virulence

Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

A auto-estima de indivíduos que foram submetidos à cirurgia de revascularização do miocárdio La autoestima de individuos que fueron sometidos a cirurgía de revascularización del miocardio The self-esteem of individual who have been submitted to coronary artery bypass graft surgery

Estudo descritivo e correlacional com objetivos de medir a auto-estima de indivíduos submetidos à cirurgia de revascularização do miocárdio e correlacionar a auto-estima com variáveis sócio-demográficas e clínicas. Uma amostra de 97 pacientes ambulatoriais foi entrevistada. Os dados foram analisados através de estatística descritiva, teste de Correlação de Pearson, testes Mann-Whitney e Kruskal Wallis. A confiabilidade da escala foi verificada (alfa de Cronbach de 0,79) e a média encontrada para auto-estima foi 32,22 (intervalo possível de 10 a 40). Encontramos correlação, estatisticamente significante, apenas para auto-estima e sexo. Concluímos que os participantes apresentavam elevada auto-estima a qual não estava correlacionada com outras variáveis.<br>Estudio descriptivo y correlacional realizado con los objetivos de medir la autoestima de individuos sometidos a cirugía de revascularización del miocardio y de correlacionar la autoestima con variables sociodemográficas y clínicas. Fue entrevistada una muestra de 97 pacientes de consulta externa. Los datos fueron analizados por estadística descriptiva, test de Correlación de Pearson, tests Mann-Whitney y Kruskal Wallis. Se verificó la confiabilidad de la escala alfa de Cronbach de 0,79 y la media encontrada para autoestima fue de 32.22 (intervalo posible de 10 a 40). Encontramos correlación, estadísticamente significativa, apenas para autoestima y sexo. Concluimos que los participantes presentaban elevada autoestima, la cual no estaba correlacionada con otras variables.<br>This is descriptive and correlational study that measured the self-esteem of individuals submitted to coronary artery bypass graft surgery and correlated the self-esteem with socio-demographic and clinical variables. A sample of 97 outpatients was interviewed. Data were analyzed by means of descriptive statistics, Pearson's Correlation test, Mann-Whitney and Kruskal Wallis tests. The reliability of the scale was verified (Cronbach alfa was 0.79) and the average for self-esteem was found to be 32.22 (possible range from 10 to 40). Statistically significant correlation was found only between self-esteem and gender. The conclusion is that the participants had a high level of self-esteem, which was not correlated to other variables