Browsing by Author "Ferreira, I.C.F.R."
Now showing 1 - 2 of 2
Results Per Page
Sort Options
- 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.
- 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.