RESUMO
BACKGROUND: The aim of this work was to evaluate the interactions between aminoglycosides and the ethyl-acetate fraction of the fern Lygodium venustum SW (EAFLV) METHODS: The ethyl-acetate fraction was obtained from the ethanol extract of L. venustum and was assayed via the checkerboard method associated with aminoglycosides against two bacterial strains multiresistant to antibiotics. RESULTS: The antibiotic activity of all drugs, when associated with the ethyl-acetate fraction, was enhanced in an additive manner, except for the association between EAFLV and amikacin, which showed a synergistic interaction against the Escherichia coli strain. CONCLUSIONS: The results indicated that L. venustum can be a source of secondary metabolites to be used in association with antibiotics like aminoglycosides in antibiotic chemotherapy against resistant bacteria.
Assuntos
Aminoglicosídeos/farmacologia , Antibacterianos/farmacologia , Produtos Biológicos/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Gleiquênias/química , Fenóis/farmacologia , Amicacina/farmacologia , Aminoglicosídeos/química , Antibacterianos/química , Produtos Biológicos/química , Sinergismo Farmacológico , Escherichia coli/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Fenóis/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Staphylococcus aureus/efeitos dos fármacosRESUMO
BACKGROUND: Escherichia coli is known to produce enterotoxins whose properties and role in diarrheal disease have been extensively investigated; besides, this bacterium is related to several extra-intestinal problems in the intensive care unit and in surgical wound infections. Some species of Staphylococcus are recognized as etiological agents of opportunistic infections in animals and humans. This study is the first test on the modulation of antibiotic activity by Croton campestris A. against multiresistant strains of E. coli and Staphylococcus aureus. METHODS: In this study, the hexane and methanol extract of C. campestris A. was tested for antibacterial activity alone and in combination with aminoglycosides against bacterial strains. The synergy of the methanol and hexane extract was verified by microdilution method. RESULTS: A synergistic effect of both extracts combined with the aminoglycosides was demonstrated. CONCLUSIONS: It is suggested that the extracts from C. campestris A. could be used as a source of natural product derived from this plant with resistance-modifying antibacterial activity, providing a new weapon against the problem of bacterial resistance to antibiotics.
