Deciphering the contribution of biofilm to the pathogenesis of peritoneal dialysis infections: characterization and microbial behaviour on dialysis fluids

Infections are major complications in peritoneal dialysis (PD) with a multifactorial etiology that comprises patient, microbial and dialytic factors. This study aimed at investigating the contribution of microbial biofilms on PD catheters to recalcitrant infections and their interplay with PD related-factors. A prospective observational study was performed on 47 patients attending Centro Hospitalar of Porto and Vila Nova de Gaia/Espinho to whom the catheter was removed due to infectious (n = 16) and non-infectious causes (n = 31). Microbial density on the catheter was assessed by culture methods and the isolated microorganisms identified by matrix-assisted laser desorption/ionization time-of-flight intact cell mass spectrometry. The effect of conventional and three biocompatible PD solutions on 16 Coagulase Negative Staphylococci (CNS) and 10 Pseudomonas aeruginosa strains planktonic growth and biofilm formation was evaluated. Cultures were positive in 87.5% of the catheters removed due infectious and 90.3% removed due to non-infectious causes. However, microbial yields were higher on the cuffs of catheters removed due to infection vs. non-infection. Staphylococci (CNS and Staphylococcus aureus) and P. aeruginosa were the predominant species: 32% and 20% in the infection and 43.3% and 22.7% in the non-infection group, respectively. In general, PD solutions had a detrimental effect on planktonic CNS and P. aeruginosa strains growth. All strains formed biofilms in the presence of PD solutions. The solutions had a more detrimental effect on P. aeruginosa than CNS strains. No major differences were observed between conventional and biocompatible solutions, although in icodextrin solution biofilm biomass was lower than in bicarbonate/lactate solution. Overall, we show that microbial biofilm is universal in PD catheters with the subclinical menace of Staphylococci and P. aeruginosa. Cuffs colonization may significantly contribute to infection. PD solutions differentially impact microbial species. This knowledge is important for the development of infection diagnosis, treatment and preventive strategies.This work received support from a Sociedade Portuguesa de Nefrologia (http://www.spnefro.pt) research grant to AR and a Fundação para a Ciência e Tecnologia (http://www.fct.pt) post doc grant (SFRH/BPD/73663/2010) to MM. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Estratégias de ensino das habilidades do pensamento crítico na enfermagem Estrategias de enseñanza de las habilidades del pensamiento crítico en enfermería Strategies for teaching the critical thinking abilities in nursing

Objetivou-se caracterizar estratégias de ensino utilizadas na enfermagem para desenvolver habilidades do pensamento crítico. Elaborou-se uma revisão integrativa nas bases de dados Web of Science e Cumulative Index of Nursing and Allied Health Literature (CINAHL), com os descritores critical thinking, nursing e teaching, no período de 1987 a 2008. A amostra constitui-se de 64 artigos e a análise permitiu a identificação de 27 estratégias de ensino do pensamento crítico aplicadas na enfermagem. Dentre estas, as cinco mais citadas foram: questionamento, estudo de caso, ensino online e aprendizagem interativa, mapa conceitual e aprendizagem baseada em problemas. Diferentes estratégias reveladas neste estudo evidenciam uma gama de possibilidades que poderão ser aplicadas no ensino e na prática clínica. Conclui-se que o desenvolvimento de habilidades do pensamento crítico por meio destas estratégias pode proporcionar a formação de profissionais mais críticos e reflexivos.<br>El objetivo es caracterizar estrategias de enseñanza utilizadas en enfermería para desarrollar habilidades del pensamiento crítico. Fue elaborada una revisión integrativa en las bases de datos Web of Science y Cumulative Index of Nursing and Allied Health Literature (CINAHL), con los descriptores critical thinking, nursing y teaching, en el período de 1987 a 2008. La muestra se constituye de 64 artículos cuyo análisis permitió la identificación de 27 estrategias de enseñanza del pensamiento crítico aplicadas a la enfermería. Entre estas, las cinco más citadas fueron: cuestionamiento, estudio de caso, enseñanza online y aprendizaje interactivo, mapa conceptual y aprendizaje con base a problemas. Diferentes estrategias reveladas en este estudio evidencian una gama de posibilidades que podrán ser aplicadas a la enseñanza y a la práctica clínica. Se concluye que el desarrollo de habilidades del pensamiento crítico a través de estas estrategias puede proporcionar la formación de profesionales más críticos y reflexivos.<br>This study aimed characterize the teaching strategies applied to nursing in order to develop critical thinking skills. An integrative review was elaborated on the Web of Science and Cumulative Index of Nursing and Allied Health Literature (CINAHL) data base, with the descriptors critical thinking, nursing and teaching, from 1987 to 2008. The sample comprised 64 articles and the analysis provided the identification of 27 strategies for teaching critical thinking in nursing. Among those, the most referred to were questioning, case study, online teaching and interactive learning, concept map and teaching based on problem solving. Different strategies described in the study revealed a wide range of possibilities which can be applied to teaching and to clinical practice. It was concluded that the development of the critical thinking skills through these teaching strategies can help nursing students to be more critical and reflexive