Browsing by Issue Date, starting with "2022-01-12"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
- Involvement of the Iron-Regulated Loci hts and fhuC in Biofilm Formation and Survival of Staphylococcus epidermidis within the HostPublication . Oliveira, Fernando; Lima, Tânia; Correia, Alexandra; Silva, Ana Margarida; Soares, Cristina; Morais, Simone; Weißelberg, Samira; Vilanova, Manuel; Rohde, Holger; Cerca, NunoStaphylococcus epidermidis is a major nosocomial pathogen with a remarkable ability to persist on indwelling medical devices through biofilm formation. Nevertheless, it remains intriguing how this process is efficiently achieved under the host’s harsh conditions, where the availability of nutrients, such as essential metals, is scarce. Following our previous identification of two iron-regulated loci putatively involved in iron transport, hts and fhuC, we assessed here their individual contribution to both bacterial physiology and interaction with host immune cells. Single deletions of the hts and fhuC loci led to marked changes in the cell iron content, which were partly detrimental for planktonic growth and strongly affected biofilm formation under iron-restricted conditions. Deletion of each of these two loci did not lead to major changes in S. epidermidis survival within human macrophages or in an ex vivo human blood model of bloodstream infection. However, the lack of either hts or fhuC loci significantly impaired bacterial survival in vivo in a murine model of bacteremia. Collectively, this study establishes, for the first time, the pivotal role of the iron-regulated loci hts and fhuC in S. epidermidis biofilm formation and survival within the host, providing relevant information for the development of new targeted therapeutics against this pathogen
- The relation between functional parameters, C-reactive protein and erythrocyte sedimentation rate in ankylosing spondylitis: a cross-sectional studyPublication . Lopes, Sofia Manuela da Rocha; Duarte, José Alberto Ramos; Santos, Paula Clara; Mesquita, Cristina Teresa Torrão CarvalhoAnkylosing spondylitis (AS) is a chronic inflammatory rheumatic disease characterised by inflammation of the spine and the sacroiliac joints and stiffness, which leads to a progressive decline in the quality of life of individuals. Bath indices are considered the principal functional outcome measure and Erythrocyte Sedimentation Rate (ESR) and C-Reactive Protein (CRP) are the most widely used biomarkers in AS to assess disease activity. To characterise individuals with AS and to examine the association between functional parameters and biomarkers. Thirty-one patients were recruited from the National Association of Ankylosing Spondylitis (ANEA) – Centre of northern region of Portugal, between February 2014 and June 2015, to be included in the present study. The Bath indices [Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI) and Bath Ankylosing Spondylitis Metrology Index (BASMI)], the Neck Disability Index (NDI), the Oswestry Disability Index (ODI) and laboratory parameters such as ESR and CRP were analysed. The participants’ mean age was 42.77 (±14.37) years, with 18 (58.1%) women and 13 (41.9%) men. The mean scores were 3.55 (BASDAI), 2.78 (BASFI) and 2.58 (BASMI). The final mean scores were 25.81± 18.36 (NDI) and 23.29±15.32 (ODI). We found a negative association between ESR and BASDAI (β=-0.038, p=0.025), and between ESR and BASFI (β=-0.044, p=0.013). As to CRP, there was no statistically significant association between Bath indices. This cross-sectional study in AS patients demonstrated that, on the one hand, this sample had a high education level, having been diagnosed with AS for more than 15 years, with a moderate disability and, on the other hand, with the adjustment of education level and years since diagnosis, there was an association between ESR and BASDAI and BASFI scores.