Browsing by Author "Martins, A."
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- Antimicrobial activity of phenolic compounds identified in wild mushrooms, SAR analysis and docking studiesPublication . Alves, M. J.; Ferreira, I. C. F. R.; Froufe, H. J. C.; Abreu, Rui M. V.; Martins, A.; Pintado, M.Aim and Methods: Although the antimicrobial activity of extracts from several mushroom species has been reported, studies with the individual compounds present in that extracts are scarce. Herein, the antimicrobial activity of different phenolic compounds identified and quantified in mushroom species from all over the world was evaluated. Furthermore, a structure-activity relationship (SAR) analysis and molecular docking studies were performed, in order to provide insights into the mechanism of action of potential antimicrobial drugs for resistant micro-organisms. Results: 2,4-Dihydroxybenzoic and protocatechuic acids were the phenolic compounds with higher activity against the majority of Gram-negative and Gram-positive bacteria. Furthermore, phenolic compounds inhibited more MRSA than methicillin-susceptible Staphylococcus aureus. MRSA was inhibited by 2,4-dihydroxybenzoic, vanillic, syringic (MICs = 0.5 mg ml(-1)) and p-coumaric (MIC = 1 mg ml(-1)) acids, while these compounds at the same concentrations had no inhibitory effects against methicillin-susceptible Staph. aureus. Conclusions: The presence of carboxylic acid (COOH), two hydroxyl (OH) groups in para and ortho positions of the benzene ring and also a methoxyl (OCH3) group in the meta position seems to be important for anti-MRSA activity. Significance and Impact of the Study: Phenolic compounds could be used as antimicrobial agents, namely against some micro-organisms resistant to commercial antibiotics.
- Antimicrobial activity of wild mushroom extracts against clinical isolates resistant to different antibioticsPublication . Alves, M.J.; Ferreira, I.C.F.R.; Martins, A.; Pintado, M.E.Aims: This work aimed to screen the antimicrobial activity of aqueous methanolic extracts of 13 mushroom species, collected in Braganc¸a, against several clinical isolates obtained in Hospital Center of Tra´s-os-Montes and Alto Douro, Portugal. Methods and Results: Microdilution method was used to determine the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). MIC results showed that Russula delica and Fistulina hepatica extracts inhibited the growth of gram-negative (Escherichia coli, Morganella morganni and Pasteurella multocida) and gram-positive (Staphylococcus aureus, MRSA, Enterococcus faecalis, Listeria monocytogenes, Streptococcus agalactiae and Streptococcus pyogenes) bacteria. A bactericide effect of both extracts was observed in Past. multocida, Strep. agalactiae and Strep. pyogenes with MBC of 20, 10 and 5 mg ml 1, respectively. Lepista nuda extract exhibited a bactericide effect upon Past. multocida at 5 mg ml 1 and inhibited Proteus mirabilis at 20 mg ml 1. Ramaria botrytis extract showed activity against Enterococcus faecalis and L. monocytogenes, being bactericide for Past. multocida, Strep. agalactiae (MBCs 20 mg ml 1) and Strep. pyogenes (MBC 10 mg ml 1). Leucopaxillus giganteus extract inhibited the growth of E. coli and Pr. mirabilis, being bactericide for Past. multocida, Strep. pyogenes and Strep. agalactiae. Conclusions: Fistulina hepatica, R. botrytis and R. delica are the most promising species as antimicrobial agents. Significance and Impact of the Study: Mushroom extracts could be an alternative as antimicrobials against pathogenic micro-organisms resistant to conventional treatments.
- Building up Undergraduate Skills – empirical evidence from a Portuguese UniversityPublication . Oliveira, Eva; Sottomayor, Miguel; Meireles, A.; Martins, A.; Rocha, M.This study presents preliminary results of the PSP Project, addressing students‟ soft skills development within the context of HEI. Theoretical framework is grounded in Person-Environment Fit theories (Rounds & Hesketh, 1994), and also in Evans (2001) starfish model. Study 1 aimed to identify Economics and Business graduates‟ Market-Valued Skills Profile, collecting data through semi-structured interviews with HR managers and former students focus groups. Study 2 assessed students‟ confidence level regarding skills using a self-report questionnaire (Miles & Grummon, 2006). Career development representations were also assessed (Savickas, 2002; Gonçalves, 2006). Additional data was collected through open-ended questions focusing on work and other extracurricular experiences. Results from Study 1 highlight soft skills as multidimensional construct where different interrelated skills contribute to graduates‟ employability. Study 2 reveals students‟ positive self-perception regarding those skills, although limited vocational experiences were reported.
- Opportunities to strengthen the link between higher education institutions and working world: a test of competing modelsPublication . Rocha, Magda; Oliveira, Eva Dias de; Martins, A.; Sá, Rita; Couto, Andreia
- Psychometric properties of the students career concerns inventory: 1st. and 2nd. order confirmatory factor analysisPublication . Rocha, Magda; Martins, A.; Oliveira, Eva Dias de; Sá, Rita; Couto, Andreia
- Salivary diagnosis: miRNA’s new directionsPublication . Sousa, S.; Martins, J. E.; Martins, A.; Rosa, N.; Santos, L.; Correia, M. J.; Barros, M.
- Wild mushroom extracts potentiate the action of standard antibiotics against multiresistant bacteriaPublication . Alves, Maria José; Ferreira, I.C.F.R.; Lourenço, I.; Castro, A.; Pereira, L.; Martins, A.; Pintado, M.Aims: The main objective of this study 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 multiresistant micro-organisms (Escherichia coli, extended-spectrum betalactamase- producing (ESBL) E. 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 multiresistant bacteria. Significance and Impact of the Study: Mushroom extracts could decrease therapeutic doses of standard antibiotics and reduce micro-organism’s resistance to those drugs.