SHORT COMMUNICATION Species of Agave with antimicrobial activity against selected pathogenic bacteria and fungi A ´ ngeles Vera ´stegui Æ Julia Verde Æ Santos Garcı ´a Æ Norma Heredia Æ Azucena Oranday Æ Catalina Rivas Received: 5 June 2007 / Accepted: 4 September 2007 / Published online: 21 September 2007 Ó Springer Science+Business Media B.V. 2007 Abstract 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 inhi- bition. 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. Keywords Agave Á Antibacterial Á Antifungal Á Antimicrobial Á Microbicidal Á Natural products Á Plant extracts Introduction Natural products derived from plants offer a new source of biologicals that may have a great impact on infectious disease and overall human health (Conner 1993; Balandrin et al. 1985). Some Agave plants produce medically useful substances such as vitamins and steroid precursors (Gentry 1982; Sanchez 2005). In addition, the stem of some species yields a soap substitute, and the pulp has been used as a fabric stain remover. Various species are used to produce drinks including fermented aguamiel or pulque and fermented and distilled mezcal or tequila. Many Agave species grow on the dry, rocky slopes of the Chihuahuan and Sonoran deserts. A. scabra and A. lecheguilla are abundant from southeastern New Mexico and southwestern Texas in the United States through the Chihuahuan desert to the states of Mexico and Hidalgo in Mexico. A. picta is also very abundant in this ecosystem. The range of A. lophanta extends from southeastern Texas southward into Mexico and along the east coast of Mexico to central Veracruz (Gentry 1982). The antimicrobial activity of these succulents has not been thoroughly investigated. Cryptococcus neoformans is a yeast that causes a sub- acute or chronic infection most frequently involving the tissue of the central nervous system, but occasionally producing lesions in the skin, bones, lungs or other internal organs. Trichophyton and Microsporum are two genera of fungi that are associated with the ‘‘tineas’’ which are fungal infections of the skin, hair, and nails. Sporothrix schenckii is a pathogenic dimorphic fungus that can be inhaled from the environment or, more commonly, enter the human body through skin wounds. Skin lesions begin as erythematous nodules, and infection may ultimately spread through the lymphatic system, resulting in tracks of lesions similar to the initial nodules (Larone 1995). Infectious and toxigenic pathogens transmitted through food have been recognized for over 100 years. Staphylo- coccus aureus, Yersinia enterocolitica, Vibrio cholerae, A ´ . Vera ´stegui Á J. Verde Á S. Garcı ´a (&) Á N. Heredia Á A. Oranday Á C. Rivas Facultad de Ciencias Biolo ´gicas, Universidad Auto ´noma de Nuevo Leo ´n, Apdo. Postal 124-F, San Nicolas, NL 66451, Mexico e-mail: santos@microbiosymas.com 123 World J Microbiol Biotechnol (2008) 24:1249–1252 DOI 10.1007/s11274-007-9563-8