RESUMO
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.