Evidence for inter- and intra-species biofilm formation variability among a small group of coagulase-negative staphylococci

Coagulase-negative staphylococci (CoNS) are common bacterial colonisers of the human skin. They are often involved in nosocomial infections due to biofilm formation in indwelling medical devices. While biofilm formation has been extensively studied in Staphylococcus epidermidis, little is known regarding other CoNS species. Here, biofilms from six different CoNS species were characterised in terms of biofilm composition and architecture. Interestingly, the ability to form a thick biofilm was not associated with any particular species, and high variability on biofilm accumulation was found within the same species. Cell viability assays also revealed different proportions of live and dead cells within biofilms formed by different species, although this parameter was particularly similar at the intra-species level. On the other hand, biofilm disruption assays demonstrated important inter- and intra-species differences regarding extracellular matrix composition. Lastly, confocal laser scanning microscopy (CLSM) experiments confirmed this variability, highlighting important differences and common features of CoNS biofilms. We hypothesised that the biofilm formation heterogeneity observed was rather associated with biofilm matrix composition than with cells themselves. Additionally, our results indicate that polysaccharides, DNA and proteins are fundamental pieces in the process of CoNS biofilm formation.

“PApi – Pais por Inteiro” Programa de intervenção em grupo para o ajustamento pessoal e a promoção da coparentalidade positiva em pais divorciados

O presente artigo apresenta o programa de intervenção em grupo para pais divorciados, Pais por Inteiro (PApi). Fundamentados na revisão da literatura com a qual o artigo se inicia, os objectivos gerais do programa – promover a coparentalidade positiva, a construção de um projecto de binuclearidade familiar e a reflexão e aprofundamento das trajectórias individuais de cada pai – são descritos, assim como as três macrocomponentes psicoterapêuticas ao longo das quais estes objectivos se desenvolvem – exposição dos processos de divórcio, partilha experiencial e treino de competências e mudança desenvolvimental. O artigo oferece ainda, no final, uma mais detalhada clarificação dos objectivos, materiais e actividades planeadas para cada das dez sessões que compõem o PApi.

Activity of carvacrol against Coagulase-negative Staphylococci biofilm related infections

Dissertação de mestrado em Bioengenharia