Reactive oxygen species generation mediated by NADPH oxidase and PI3K/Akt pathways contribute to invasion of Streptococcus agalactiae in human endothelial cells

BACKGROUND Streptococcus agalactiae can causes sepsis, pneumonia, and meningitis in neonates, the elderly, and immunocompromised patients. Although the virulence properties of S. agalactiae have been partially elucidated, the molecular mechanisms related to reactive oxygen species (ROS) generation in infected human endothelial cells need further investigation. OBJECTIVES This study aimed to evaluate the influence of oxidative stress in human umbilical vein endothelial cells (HUVECs) during S. agalactiae infection. METHODS ROS production during S. agalactiae-HUVEC infection was detected using the probe CM-H2DCFDA. Microfilaments labelled with phalloidin-FITC and p47phox-Alexa 546 conjugated were analysed by immunofluorescence. mRNA levels of p47phox (NADPH oxidase subunit) were assessed using Real Time qRT-PCR. The adherence and intracellular viability of S. agalactiae in HUVECs with or without pre-treatment of DPI, apocynin (NADPH oxidase inhibitors), and LY294002 (PI3K inhibitor) were evaluated by penicillin/gentamicin exclusion. Phosphorylation of p47phox and Akt activation by S. agalactiae were evaluated by immunoblotting analysis. FINDINGS Data showed increased ROS production 15 min after HUVEC infection. Real-Time qRT-PCR and western blotting performed in HUVEC infected with S. agalactiae detected alterations in mRNA levels and activation of p47phox. Pre-treatment of endothelial cells with NADPH oxidase (DPI and apocynin) and PI3K/Akt pathway (LY294002) inhibitors reduced ROS production, bacterial intracellular viability, and generation of actin stress fibres in HUVECs infected with S. agalactiae. CONCLUSIONS ROS generation via the NADPH oxidase pathway contributes to invasion of S. agalactiae in human endothelial cells accompanied by cytoskeletal reorganisation through the PI3K/Akt pathway, which provides novel evidence for the involvement of oxidative stress in S. agalactiae pathogenesis.

Comportamento informacional de gestores de uma superintendência regional de saúde / Informational behavior of managers in regional superintendence of health

Objetivo: compreender o comportamento informacional de gestores em uma Superintendência Regional de Saúde. Metodologia: estudo de caso, de abordagem qualitativa, que utilizou como referencial teórico o comportamento informacional de Wilson. Realizaram-se entrevistas com gestores de uma superintendência em Minas Gerais, analisadas a partir da Análise de Conteúdo. Resultados: as necessidades e busca por informações estavam atreladas às demandas de soluções emergenciais. Dentre as várias fontes, as pessoas foram reconhecidas em um fluxo informacional verticalizado. Informações de baixa qualidade foram utilizadas, gerando incerteza para as decisões. Conclusão: o comportamento informacional dos gestores é assistemático e possui fragilidades que podem dificultar o planejamento e a tomada de decisões assertivas.

Objective: to understand the informational behavior of managers in a regional superintendence of health. Methodology: Case study with qualitative approach that used Wilson behavior as a theoretical reference. Interviews were conducted with managers of a superintendency in Minas Gerais, and analyzed from the Content Analysis. Results: the necessities and pursuit for information was linked to the demands of emergency solutions. Among the various sources, people were recognized in a vertical information flow. Low quality of information were used generating uncertainty in decisions. We conclude that the informational behavior of managers is unsystematic and potentially damaging to the management of information.

Objetivo: Estudio de caso con enfoque cualitativo. Buscado entender el comportamiento informativo de los gestores en Salud. Utilizamos la teoría del comportamiento de información de Wilson. Entrevistamos a los gestores de una superintendencia de salud en Minas Gerais. Se utilizó el Análisis de Contenido para analizar los datos. Las necesidades y búsqueda de información estaba vinculada a las demandas de soluciones emergenciales. Las personas fueron reconocidas como fuentes en un flujo de información vertical. Hubo baja calidad de la información que genera decisiones inciertas. Se concluye que el comportamiento de información de los gestores no es sistemática y potencialmente dañino para la gestión de la información.

Interferon-γ inhibits group B Streptococcus survival within human endothelial cells

Endothelial dysfunction is a major component of the pathophysiology of septicaemic group B Streptococcus (GBS) infections. Although cytokines have been shown to activate human umbilical vein endothelial cells (HUVECs), the capacity of interferon (IFN)-γ to enhance the microbicidal activity of HUVECs against GBS has not been studied. We report that the viability of intracellular bacteria was reduced in HUVECs activated by IFN-γ. Enhanced fusion of lysosomes with bacteria-containing vacuoles was observed by acid phosphatase and the colocalisation of Rab-5, Rab-7 and lysosomal-associated membrane protein-1 with GBS in IFN-γ-activated HUVECs. IFN-γ resulted in an enhancement of the phagosome maturation process in HUVECs, improving the capacity to control the intracellular survival of GBS.