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- Phenolic profile and antimicrobial activity of different dietary supplements based on Cochlospermum angolensis WelwPublication . Pereira, Carla; Barros, Lillian; Alves, Maria José; Pereira, Liliana; Santos-Buelga, Celestino; Ferreira, Isabel C.F.R.Three different formulations (infusion, pills and syrup) of Cochlospermum angolensis were characterized by HPLC-DAD-ESI/MS regarding phenolic composition, and evaluated by their in vitro antimicrobial activity against clinical isolates of multiresistant bacteria. Infusion and pills showed the highest variety of phenolic compounds, with eleven molecules identified. Protocatechuic acid was only present in infusions, being the most abundant compound, while (epi)gallocatechin-O-gallate was the main molecule identified in pills and eucaglobulin/globulusin in syrup. Infusion revealed antimicrobial activity against all the studied bacteria with the exception of Proteus mirabilis whereas the pills revealed activity in Escherichia coli spectrum extended producer of β-lactamases and methicillin-resistant Staphylococcus aureus. In the syrup there was no antimicrobial activity detected, which is in agreement with its low concentrations of phenolic compounds. None of the formulations inhibited P. mirabilis. Considering the obtained results, C. angolensis infusion can be considered a good source of phenolic compounds as well as a good antimicrobial agent.
- Ionic regulation and shell mineralization in the bivalve Anodonta cygnea following heavy metal exposurePublication . Lopes-Lima, Manuel; Freitas, Susana; Pereira, Liliana; Gouveia, Maria Eugénia; Hinzmann, Mariana; Checa, Antonio; Machado, JorgeFreshwater mussels are one of the most imperiled faunistic groups in the world and environmental exposure to toxic heavy metals, which result in deregulation of calcium absorption and deposition in the laboratory, may be a contributing factor in their decline. To address potential effects of heavy-metal exposure on calcium transport and metabolism in freshwater bivalves, adult Anodonta cygnea (L., 1758) were exposed to a sublethal concentration (1.0 × 10−6 mol/L) of essential (Zn2+ and Cu2+) or nonessential (Pb2+ and Cr3+) metal for 30 days in the laboratory. Inorganic composition of extrapallial, haemolymph, heart, and pericardium fluids, and kidney tissue, as well as shell morphology by scanning electron microscopy, were compared in treated and untreated mussels. Calcium levels in fluids varied after exposure to any of the metals investigated, although the magnitude and threshold of effect were metal- and compartment-specific. Ca2+ levels increased robustly in all fluids following exposure to Zn2+, Cu2+, or Cr3+, whereas levels decreased significantly in heart fluid alone following Pb2+ exposure (p < 0.05). In constrast to exposure to the other metals, Cu2+ revealed an interesting reverse-accumulation pattern, decreasing in the fluids but not in the kidney, where it clearly accumulates for excretion. In addition, whereas essential Cu2+ and Zn2+ are closely regulated, the nonessential metals Pb2+ and Cr3+ increase to very high levels. Drastic alterations in shell morphology, specifically the structure of border and inner pallial regions of the nacreous layer, were observed after Cu2+ or Cr3+ exposure. Collectively, data suggest that prolonged exposure to a sublethal concentration of these heavy metals can adversely affect compartmental calcium availability and shell composition in A. cygnea.
- Propensity for biofilm formation by clinical isolates from urinary tract infections: developing a multifactorial predictive model to improve the antibiotherapyPublication . Alves, Maria José; Barreira, João C.M.; Carvalho, Inês; Trinta, Luís; Pereira, Liliana; Ferreira, Isabel C.F.R.; Pintado, ManuelaA group of biofilm-producing bacteria isolated from patients with urinary tract infections was evaluated, identifying the main factors contributing to biofilm formation. Among the 156 isolates, 58 (37.2%) were biofilm producers. The bacterial species (P<0.001), together with patient's gender (P = 0.022), were the factors with the highest influence for biofilm production. There was also a strong correlation of catheterization with biofilm formation, despite being less significant (P = 0.070) than species or gender. In fact, some of the bacteria isolated were biofilm producers in all cases. With regard to resistance profile among bacterial isolates, β-lactam antibiotics presented the highest number of cases/percentages--ampicillin (32/55.2%), cephalothin (30/51.7%), amoxicillin/clavulanic acid (22/37.9%)--although the carbapenem group still represented a good therapeutic option (2/3.4%). Quinolones (nucleic acid synthesis inhibitors) also showed high resistance percentages. Furthermore, biofilm production clearly increases bacterial resistance. Almost half of the biofilm-producing bacteria showed resistance against at least three different groups of antibiotics. Bacterial resistance is often associated with catheterization. Accordingly, intrinsic (age and gender) and extrinsic (hospital unit, bacterial isolate and catheterization) factors were used to build a predictive model, by evaluating the contribution of each factor to biofilm production. In this way, it is possible to anticipate biofilm occurrence immediately after bacterial identification, allowing selection of a more effective antibiotic (among the susceptibility options suggested by the antibiogram) against biofilm-producing bacteria. This approach reduces the putative bacterial resistance during treatment, and the consequent need to adjust antibiotherapy.
- Wild mushroom extracts potentiate the action of standard antibiotics against multiresistant bacteriaPublication . Alves, Maria José; Ferreira, Isabel C.F.R.; Lourenço, Inês; Castro, Ana; Pereira, Liliana; Martins, Anabela; Pintado, ManuelaThe main objective of the present work was to evaluate the capacity of wild mushroom extracts to potentiate the action of standard antibiotics, through synergisms that allow a decrease in their therapeutic doses and ultimately contribute to the reduction of resistances. Methods and Results: Wild mushroom extracts were applied to different multi-resistant microorganisms (Escherichia coli, Extended-spectrum beta-lactamase-producing (ESBL) Escherichia coli and Methicillin-resistant Staphylococcus aureus (MRSA), combined with commercial antibiotics (Penicillin, Ampicillin, Amoxicillin/Clavulanic acid, Cefoxitin, Ciprofloxacin, Cotrimoxazol, Levofloxacin). Microdilution method was used to determine minimum inhibitory concentrations (MICs). The results obtained showed higher synergistic effects against MRSA than against E. coli. Mycena rosea and Fistulina hepatica were the best extracts for synergistic effects against MRSA. The efficiency of Russula delica extract against E. coli 1 (resistant to Ampicillin, Ciprofloxacin and Trimethoprim/Sulfasoxazole) and E. coli 2 (resistant to Amoxicillin/Clavulanic acid and Ampicillin) was higher than that of Leucopaxillus giganteus extract; nevertheless the latter extract exhibited better synergistic effects against ESBL E. coli. Conclusions: This study shows that, similarly to plants, some mushroom extracts can potentiate the action of antibiotics extensively used in clinical practice for Gram-positive or Gram-negative bacteria, with positive action even against multi-resistant bacteria. Significance and Impact of the Study: Mushroom extracts could decrease therapeutic doses of standard antibiotics and reduce microorganism’s resistance to those drugs.
- Suplementos dietéticos à base de Cochlospermum angolensis Welw.: atividade antimicrobiana e compostos fenólicosPublication . Barros, Lillian; Pereira, Carla; Alves, Maria José; Pereira, Liliana; Santos-Buelga, Celestino; Ferreira, Isabel C.F.R.Cochlospermum angolensis Welw. (borututu) é uma árvore tropical pertencente à família das Cochlospermaceae e amplamente utilizada pelas suas propriedades medicinais, incluindo no tratamento da malária, da icterícia e de doenças hepáticas.1 Neste trabalho, foram caracterizados os compostos fenólicos presentes em três formulações (infusões, comprimidos e xarope) à base desta planta, utilizando cromatografia líquida de alta eficiência acoplada a detetores de díodos e de espetrometria de massa (HPLC-DAD-ESI/MS). Esses compostos foram relacionados com a atividade antimicrobiana das mesmas formulações contra isolados clínicos de bactérias multirresistentes (Escherichia coli, Escherichia coli produtora de β-lactamases de espectro estendido (ESBLs), Proteus mirabilis, Staphylococcus aureus resistentes à meticilina (MRSA) e Pseudomonas aeruginosa). As infusões e os comprimidos revelaram uma maior variedade de compostos fenólicos, com onze moléculas identificadas. O ácido protocatéquico foi encontrado apenas nas infusões, sendo o composto maioritário, enquanto a (epi)galocatequina-O-galato e a eucaglobulina/globulusina foram as moléculas mais abundantes nos comprimidos e no xarope, respetivamente. O ácido elágico e derivados metilados, a eucaglobulina/globulusina B e a (epi)galocatequina-O-galato foram compostos comuns a todas as formulações. As infusões apresentaram propriedades antimicrobianas contra todas as bactérias testadas, com exceção de P. mirabilis, ao passo que os comprimidos apenas revelaram atividade em E. coli ESBLs e MRSA. O xarope não apresentou atividade antimicrobiana, o que está em concordância com o seu baixo teor de compostos fenólicos. Nenhuma das formulações estudadas demonstrou capacidade de inibir o crescimento de P. mirabilis. Atendendo aos resultados obtidos neste estudo, as infusões de C. angolensis podem ser consideradas uma fonte de compostos fenólicos com boas propriedades antimicrobianas.
- Suplementos dietéticos à base de Cochlospermum angolensis Welw.: Atividade antimicrobiana e compostos fenólicosPublication . Barros, Lillian; Pereira, Carla; Alves, Maria José; Pereira, Liliana; Santos-Buelga, Celestino; Ferreira, Isabel C.F.R.Cochlospermum angolensis Welw. (borututu) é uma árvore tropical pertencente à família das Cochlospermaceae e amplamente utilizada pelas suas propriedades medicinais, incluindo no tratamento da malária, da icterícia e de doenças hepáticas.1 Neste trabalho, foram caracterizados os compostos fenólicos presentes em três formulações (infusões, comprimidos e xarope) à base desta planta, utilizando cromatografia líquida de alta eficiência acoplada a detetores de díodos e de espetrometria de massa (HPLC-DAD-ESI/MS). Esses compostos foram relacionados com a atividade antimicrobiana das mesmas formulações contra isolados clínicos de bactérias multirresistentes (Escherichia coli, Escherichia coli produtora de β-lactamases de espectro estendido (ESBLs), Proteus mirabilis, Staphylococcus aureus resistentes à meticilina (MRSA) e Pseudomonas aeruginosa). As infusões e os comprimidos revelaram uma maior variedade de compostos fenólicos, com onze moléculas identificadas. O ácido protocatéquico foi encontrado apenas nas infusões, sendo o composto maioritário, enquanto a (epi)galocatequina-O-galato e a eucaglobulina/globulusina foram as moléculas mais abundantes nos comprimidos e no xarope, respetivamente. O ácido elágico e derivados metilados, a eucaglobulina/globulusina B e a (epi)galocatequina-O¬-galato foram compostos comuns a todas as formulações. As infusões apresentaram propriedades antimicrobianas contra todas as bactérias testadas, com exceção de P. mirabilis, ao passo que os comprimidos apenas revelaram atividade em E. coli ESBLs e MRSA. O xarope não apresentou atividade antimicrobiana, o que está em concordância com o seu baixo teor de compostos fenólicos. Nenhuma das formulações estudadas demonstrou capacidade de inibir o crescimento de P. mirabilis. Atendendo aos resultados obtidos neste estudo, as infusões de C. angolensis podem ser consideradas uma fonte de compostos fenólicos com boas propriedades antimicrobianas.