The inhibitory effect of a non-yessotoxin-producing dinoflagellate, Lingulodinium polyedrum (Stein) Dodge, towards Vibrio vulnificus and Staphylococcus aureus

ResumenEl aumento de la resistencia bacteriana a los antibióticos ha causado preocupación a nivel mundial, por lo que se ha promovido la búsqueda de nuevos compuestos. Debido a su abundancia y diversidad, el fitoplancton marino constituye una importante fuente potencial de tales compuestos. La investigación sobre dinoflagelados ha llevado al descubrimiento de inhibidores de crecimiento bacteriano. El dinoflagelado marino Lingulodinium polyedrum causa proliferaciones algales en diferentes regiones del mundo, incluyendo México, y también se sabe que regula el crecimiento de otras especies en las aguas costeras. En este trabajo, se investiga la taxonomía de este dinoflagelado y se caracteriza la capacidad de sus extractos para inhibir el crecimiento de dos bacterias de importancia médica (Vibrio vulnificus y Staphylococcus aureus) en placas de cultivo de agar. La caracterización taxonómica se realizó por PCR y amplificación del gen de ITS, y se confirmó que la especie aislada en la costa del Pacífico de México fue L. polyedrum. Para demostrar el efecto inhibidor de los extractos de L. polyedrum, los cultivos se cosecharon por centrifugación. Los pellets de tres abundancias celulares se extrajeron con agua, metanol, hexano y cloroformo. Los experimentos en V. vulnificus mostraron una inhibición alta del crecimiento para los cuatro extractos, variando entre 77 y 98 %. Sorprendentemente, la inhibición del crecimiento fue menor cuando los extractos se originaron a partir de una mayor abundancia de células L. polyedrum, varía de 0 a 34 %. Para S. aureus, la inhibición del crecimiento también fue alta, pero no estadísticamente diferente para todos los extractos y abundancias de células, con un rango de 62 hasta 99 %. Esto resultados son prometedores para futuras aplicaciones farmacológicas. La cepa mexicana de L. polyedrum no produjo yesotoxinas detectables.

AbstractThe increased bacterial resistance to antibiotics has caused global concern, prompting the search for new compounds. Because of their abundance and diversity, marine phytoplankton are an important potential source of such compounds. Research on dinoflagellates has led to the discovery of inhibitors of bacterial growth. The marine dinoflagellate Lingulodinium polyedrum blooms in different regions of the world, including Mexico, and is also known to regulate the growth of other species in coastal waters. Here, we investigated the taxonomy of this dinoflagellate and characterized the ability of its extracts to inhibit the growth of two bacteria of medical importance (Vibrio vulnificus and Staphylococcus aureus). Taxonomic characterization was performed by PCR and gene amplification of ITS, and confirmed that the species isolated off the Pacific coast of Mexico was L. polyedrum. To prove the inhibitory effect of L. polyedrum extracts, cultures were harvested by centrifugation. Pellets from three cellular abundances were extracted with water, methanol, hexane and chloroform. The experiments on V. vulnificus showed a high growth inhibition for the four extracts, ranging from 77 to 98 %. Surprisingly, the growth inhibition was lower when the extracts originated from a higher L. polyedrum cell abundance, ranging from 0 to 34 %. For S. aureus, the growth inhibition was also high, but not statistically different for all extracts and cell abundances, ranging from 62 to 99 %. This study obtained promising results for future pharmacological applications. Our Mexican strain of L. polyedrum did not produce any detectable yessotoxins. Rev. Biol. Trop. 64 (2): 805-816. Epub 2016 June 01.

The inhibitory effect of a non-yessotoxin-producing dinoflagellate, Lingulodinium polyedrum (Stein) Dodge, towards Vibrio vulnificus and Staphylococcus aureus.

The increased bacterial resistance to antibiotics has caused global concern, prompting the search for new compounds. Because of their abundance and diversity, marine phytoplankton are an important potential source of such compounds. Research on dinoflagellates has led to the discovery of inhibitors of bacterial growth. The marine dinoflagellate Lingulodinium polyedrum blooms in different regions of the world, including Mexico, and is also known to regulate the growth of other species in coastal waters. Here, we investigated the taxonomy of this dinoflagellate and characterized the ability of its extracts to inhibit the growth of two bacteria of medical importance (Vibrio vulnificus and Staphylococcus aureus). Taxonomic characterization was performed by PCR and gene amplification of ITS, and confirmed that the species isolated off the Pacific coast of Mexico was L. polyedrum. To prove the inhibitory effect of L. polyedrum extracts, cultures were harvested by centrifugation. Pellets from three cellular abundances were extracted with water, methanol, hexane and chloroform. The experiments on V. vulnificus showed a high growth inhibition for the four extracts, ranging from 77 to 98 %. Surprisingly, the growth inhibition was lower when the extracts originated from a higher L. polyedrum cell abundance, ranging from 0 to 34 %. For S. aureus, the growth inhibition was also high, but not statistically different for all extracts and cell abundances, ranging from 62 to 99 %. This study obtained promising results for future pharmacological applications. Our Mexican strain of L. polyedrum did not produce any detectable yessotoxins.