ABSTRACT
The medicinal plants are an alternative source to the treatment of primary health care problems. An ethnobotanical study performed on Tlalchy, Ixhuacán de los Reyes, Veracruz, México, allowed the selection of nine plant species involved in infectious diseases treatments. Antimicrobial activities of ethanolic crude extracts were tested on fifteen bacterial and yeast clinical isolates. Every extract showed a level of inhibition against almost all the microorganisms assayed. According to the Clinical and Laboratory Standards Institute norms, representative results emerged over three species: T. diversifolia, C. nitidula y L. racemosa, therefore, Minimal Inhibitory Concentration values were determined on these species. The data suggest that using medicinal plants of Tlalchy is convenient, for this reason, we put forward further investigation on several species.