Species of Agave with antimicrobial activity against selected pathogenic bacteria and fungi

The in vitro antimicrobial activity against pathogenic bacteria, yeast, and molds were examined in extracts of the Agave species A. lecheguilla, A. picta, A. scabra and A. lophanta using an agar diffusion technique. The extracts of A. picta produced zones of inhibition of 9–13 mm for E. coli, L. monocytogenes, S. aureus, and V. cholerae, while B. cereus and Y. enterocolitica were not inhibited. The other Agave species did not show any detectable inhibitory activity against the bacteria tested; however, all four Agave sp. were inhibitory against all yeast and molds analyzed as evident by 9–20 mm zones of inhibition. The minimum microbicidal concentration (MMC) of the active extract ranged from 1.8 to 7.0 mg/ml for the sensitive bacteria, and 2.0–3.0 mg/ml for yeast. In the case of molds, the minimum inhibitory concentration (MIC) of the active extracts ranged from 3.0 to 6.0 mg/ml. Together, these data suggest that the Agave sp. analyzed are potential antimicrobial candidates with a broad range of activity.