Percorrer por autor "Ribeiro, Teresa"
A mostrar 1 - 2 de 2
Resultados por página
Opções de ordenação
- Long-term dissemination of acquired AmpC β-lactamases among Klebsiella spp. and Escherichia coli in Portuguese clinical settingsPublication . Freitas, Francisco; Machado, Elisabete; Ribeiro, Teresa; Novais, Ângela; Peixe, LuísaWe investigated the occurrence, diversity and molecular epidemiology of genes coding for acquired AmpC β-lactamases (qAmpC) among clinical isolates of Enterobacteriaceae lacking inducible chromosomal AmpCs in Portugal. A total of 675 isolates non-susceptible to broad-spectrum cephalosporins obtained from four hospitals and three community laboratories during a 7-year period (2002-2008) were analysed. The presence of genes coding for qAmpC was investigated by phenotypic criteria, polymerase chain reaction (PCR) and sequencing. Bacterial identification, antibiotic susceptibility testing, conjugation assays and clonal analysis were performed by standard procedures. The presence of bla qAmpC genes was detected in 50 % (50/100; 41 Klebsiella pneumoniae, 5 Escherichia coli, 4 Klebsiella oxytoca) of the presumptive qAmpC producers. DHA-1, detected in those species, was the most prevalent qAmpC (94 %, 47/50), being identified since 2003 and throughout the studied period in different institutions. Despite the high clonal diversity observed, three DHA-1-producing Klebsiella spp. clones were more frequently identified. CMY-2 (6 %, 3/50) was observed in B1-E. coli clones. Conjugative transfer was only observed in one (2 %) CMY-2-producing isolate. Most qAmpC producers (94 %, 47/50) co-expressed SHV-type and/or OXA-1 or CTX-M-32 extended-spectrum β-lactamases (ESBLs). To the authors' knowledge, this is the first description of the molecular epidemiology and the long-term dissemination of qAmpC-producing Enterobacteriaceae in Portuguese clinical settings, highlighting an evolution towards a more complex epidemiological situation regarding cephalosporin resistance in Portugal.
- Targeting skin aging: Anti-senescent potential and key enzyme modulation of Lavandula essential oilsPublication . Silva, Jorge M. Alves; Domingues, Joana; Delgado, F.M.G.; Ribeiro, Teresa; Cruz, Teresa; Salgueiro, Lígia; Girão, Henrique; Zuzarte, MónicaIntroduction: Skin aging is an inherent biological process linked to chronological aging that can be accelerated by external factors. Cellular senescence and skin enzymes are crucial players in this process and, therefore, relevant preventive and therapeutic targets. In this scenario, aromatic plants and their essential oils have gained attention as promising agents in the management of skin aging. The present study aims to explore the anti-senescent potential of Lavandula stoechas subsp. luisieri and Lavandula pedunculata essential oils on skin fibroblasts and their effect on relevant enzymes, given their anti-inflammatory effects. Methods: The chemical characterization of the essential oils was carried out by gas chromatography-mass spectrometry and their effect evaluated on etoposide-induced senescent fibroblasts during the recovery phase. Relevant markers of cellular senescence were analyzed, namely, β-galactosidase activity through a colorimetric assay, nuclear alterations by immunofluorescence, SASP secretion through ELISA, expression levels of cell cycle inhibitors by WB analysis and ultrastructural alterations using transmission electron microscopy. Modulation of key enzyme activity was determined using an in chemico approach. Results: The essential oil of L. pedunculata was characterized by high amounts of fenchone and camphor whereas that of L. stoechas subsp. luisieri showed a very peculiar chemical profile rich in rare necrodane derivatives and lavandulyl acetate. Both essential oils were effective in decreasing most of the senescence markers but L. stoechas subsp. luisieri strikingly attained significant effects at very low concentrations (6.25 μg/mL). Conclusion: These results highlight the potential of L. stoechas subsp. luisieri to mitigate cellular senescence and delay skin aging, thereby contributing to the valorization of this underexplored species in cosmeceutical and pharmaceutical applications.