Evaluación de la capacidad de inhibición de aislamientos de Streptomyces spp. obtenidos de muestras de suelo que bordean el Río Pirro en el Campus Omar Dengo, Universidad Nacional, Costa Rica
Fecha
2020
Autores
Segura Zacharkiewicz, Sara Felicia
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Resumen
Los actinomicetos son bacterias filamentosas de las cuales provienen la mayoría de los antibióticos utilizados en la medicina actual. Se obtuvieron muestras de suelo de los alrededores del río Pirro en el campus Omar Dengo de la Universidad Nacional, Costa Rica para lograr aislamientos de Streptomyces spp. e investigar las propiedades antimicrobianas de sus metabolitos contra cuatro cepas patógenas: Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, Klebsiella sp. silvestre extraído de un aislamiento clínico y Pseudomonas aeruginosa ATCC 9027. Los 19 aislamientos de Streptomyces spp. obtenidos del campo fueron sometidos a una prueba de sensibilidad para elegir los más promisorios y luego fueron fermentados en medio sólido y líquido. Se hicieron extracciones con solventes polares y se hicieron pruebas de difusión en agar por pozos y difusión por tapón de agar para identificar los halos de inhibición de mayor diámetro. El análisis estadístico mostró que la mayoría de los aislamientos presentaron actividad inhibitoria contra la Gram positiva Staphylococcus aureus, sin embargo, dos aislamientos lograron inhibir también a Escherichia coli y Klebsiella pneumoniae. En cuanto a la extracción de metabolitos, el solvente acetonitrilo en relación con DMSO y metanol, fue el mejor solvente en cual se obtuvieron halos de inhibición, pero se recomienda probar otros caldos de fermentación y solventes puros o en mezcla. Se concluye que el río Pirro es una fuente de microorganismos con potencial inhibitorio y los aislamientos evaluados tienen un potencial biotecnológico al evidenciar que producen metabolitos con importancia biomédica.
Actinomycetes are filamentous bacteria from which most of the antibiotics used in current medicine come. Soil samples were obtained from the surroundings of the Pirro River at the Omar Dengo campus of the National University, Costa Rica to achieve isolates of Streptomyces spp. and to investigate the antimicrobial properties of its metabolites against four pathogenic strains: Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, Klebsiella sp. wild-type extracted from a clinical isolate and Pseudomonas aeruginosa ATCC 9027. The 19 isolates of Streptomyces spp. obtained from the field were subjected to a sensitivity test to choose the most promising ones and then they were fermented in solid and liquid medium. Polar solvent extractions were made and agar diffusion wells and agar plug diffusion tests were done to identify the largest diameter inhibition halos. Statistical analysis showed that most of the isolates showed inhibitory activity against the Gram positive Staphylococcus aureus, however, two isolates were also able to inhibit Escherichia coli and Klebsiella pneumoniae. Regarding the extraction of metabolites, the acetonitrile solvent in relation to DMSO and methanol was the best solvent in which inhibition halos were obtained, but it is recommended to try other fermentation broths and pure or mixed solvents. It is concluded that the Pirro River is a source of microorganisms with inhibitory potential and the evaluated isolates have a biotechnological potential by showing that they produce metabolites with biomedical importance.
Actinomycetes are filamentous bacteria from which most of the antibiotics used in current medicine come. Soil samples were obtained from the surroundings of the Pirro River at the Omar Dengo campus of the National University, Costa Rica to achieve isolates of Streptomyces spp. and to investigate the antimicrobial properties of its metabolites against four pathogenic strains: Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, Klebsiella sp. wild-type extracted from a clinical isolate and Pseudomonas aeruginosa ATCC 9027. The 19 isolates of Streptomyces spp. obtained from the field were subjected to a sensitivity test to choose the most promising ones and then they were fermented in solid and liquid medium. Polar solvent extractions were made and agar diffusion wells and agar plug diffusion tests were done to identify the largest diameter inhibition halos. Statistical analysis showed that most of the isolates showed inhibitory activity against the Gram positive Staphylococcus aureus, however, two isolates were also able to inhibit Escherichia coli and Klebsiella pneumoniae. Regarding the extraction of metabolites, the acetonitrile solvent in relation to DMSO and methanol was the best solvent in which inhibition halos were obtained, but it is recommended to try other fermentation broths and pure or mixed solvents. It is concluded that the Pirro River is a source of microorganisms with inhibitory potential and the evaluated isolates have a biotechnological potential by showing that they produce metabolites with biomedical importance.
Descripción
Segura Zacharkiewicz, S. F. (2020). Evaluación de la capacidad de inhibición de aislamientos de Streptomyces spp. obtenidos de muestras de suelo que bordean el Río Pirro en el Campus Omar Dengo, Universidad Nacional, Costa Rica. [ Tesis de Licenciatura]. Universidad Nacional, Costa Rica.
Palabras clave
BACTERIAS, MICROORGANISMOS, ANTIBIÓTICOS, SUELO, HEREDIA (COSTA RICA), MICROORGANISMS, ANTIBIOTICS, BIOMEDICAL, BIOMEDICINA