The present study aimed to evaluate the antibacterial activity of aqueous extracts of Bidens sulphurea and Tanacetum vulgare L. against Staphylococcus spp. methicillin-resistant (mecA) isolates from the vaginal microbiota of pregnant women. Fifteen isolates of Staphylococcus spp. with the presence of the mecA gene, from the vaginal swabs of pregnant women, aged between 16 and 38 years, who underwent microbiological examination during the first trimester of pregnancy. The aqueous extracts of B. sulphurea and Tanacetum vulgare L. were obtained by infusion, as recommended by popular use, and then, the chemical identification of the extracts was performed by gas chromatography. The antibacterial activity of plant extracts was performed by the method of microdilution in broth. B. sulphurea extract had as major compounds: custonolide (8.06%), Isohumulene (6.19%), artemetin (21,13%), β-sitosterol (28.68%), phytol (7.36%) e 7,8-epoxylanostan-11-ol, 3-acetoxy- (7.09%). T. vulgare extract presented as the majority artemetin (13.38%), verrucarol (13.27%) and phytol (11.93%), ergosterol (5.43%), ethyl iso-allocholate (6.95%), 7,8-epoxylanostan-11-ol, 3-acetoxy- (14,46%), lycopene, 1,1',2,2'-tetrahydro-1,1'-dimethoxy-, all-trans (7.09%) e 9,19-cyclochloestene-3,7-diol, 4,14-dimethyl-, 3-acetate (8.58%). The isolates tested against aqueous extracts of B. sulphurea and T. vulgare L., obtained minimum inhibitory concentrations (MIC) between 1.17mg/mL and 37.5mg/mL, minimum bactericidal concentrations (MBC) of B. sulphurea varied between 75mg/mL and 150mg/mL, on the other hand, T. vulgare L. MBC had lower values ranging from 9.37mg/mL to 150mg/mL. It was confirmed the bactericidal and bacteriostatic activity of the tested extracts against isolates that have the mecA resistance gene, and it is possible to attest that these extracts are a therapeutic alternative.
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