Abstract

The scientific community is constantly searching for innovative substances that have antimicrobial potential and the ability to reduce or eliminate bacterial antibiotic resistance to specific drugs. This ability is known as the modulatory activity of antibiotics. Crateva tapia L., popularly known as “trapiá,” is a plant belonging to the Capparaceae family and is used in northeastern Brazil as a tonic, anti-diarrheal, antipyretic, hypotensive and muscle relaxant. We investigated the phytochemical profile and the antibiotic and modulating activity of a hydroalcoholic crude extract (CECT) against multi-drug resistant strains of Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa, all of which were isolated from surgical wounds. A phytochemical assay detected the presence of phenols and alkaloids. The minimum inhibitory concentration (MIC) of CECT against all of the strains used was ≥ 1024 µg/mL. The extract synergistically modulated the antibiotic resistance to Amikacin of S. aureus, reducing the MIC from 312.5 to 39.06 µg/mL (an 87.5% reduction). The same occurred in the case of gentamicin against S. aureus and P. aeruginosa. In both cases, the MIC was reduced from 312.5 to 78.12 µg/mL, a reduction of 75%. Although the antimicrobial activity of C. tapia extract is clinically irrelevant, it showed significant modulatory activity, justifying further fractionation and tests with other strains and antibiotics.

Key words: Antimicrobial activity, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, amikacin, gentamicin, neomycin.