Efecto antagónico in vitro de Lactobacillus spp. aislados de "tocosh" – Solanum sp., proveniente de Huánuco, frente a bacterias enteropatógenas

Abstract

According to the WHO, diarrheal diseases (DD) are the second leading cause of death in children under five worldwide. Since the Inca era, ‘tocosh’ has been characterized by its nutraceutical properties. The objective of this research was to evaluate the antagonistic effect of Lactobacillus spp. isolated from ‘tocosh’ - Solanum sp. from Huánuco, against enteropathogenic bacteria: Escherichia coli enteropathogenic (EPEC), Salmonella typhi, Shigella flexneri, and Vibrio cholerae Inaba. Methods: The population was extracted from tocosh produced in fermentation pits located in the province of Yarowilca, Obas district. The bacteria were isolated in Man Rogosa Sharpe broth, under anaerobic conditions, and incubated for 48 hours. To purify the Lactobacillus spp. strains, tests were conducted according to Bergey's Manual. In the evaluation of the antagonistic effect, the Burkholder method and the cell-free supernatant (CFS) method were used. The assay was performed in triplicate at a concentration of 2 on the MacFarland scale of lactic acid bacteria, incubated in aerobiosis at 37 °C for 18 hours. Results: Of a total of 223 samples, 44 strains showed microscopic and biochemical characteristics compatible with Lactobacillus spp. The mean inhibition halos formed by the Burkholder method were 11.36 mm against Vibrio cholerae Inaba 1.457.10, 9.86 mm against Salmonella typhi 2.240-16, 6 mm against Shigella flexneri WHO SH-15.3, and 6 mm against Escherichia coli enteropathogenic (EPEC) 2.734-18. The cell-free supernatant method obtained means of 13.62 mm against Vibrio cholerae Inaba 1.457.10, 10.52 mm against Salmonella typhi 2.240-16, 6.33 mm against Shigella flexneri WHO SH-15.3, and 6.19 mm against Escherichia coli enteropathogenic (EPEC) 2.734-18. A comparison of groups determined that the greatest effect was obtained against Vibrio cholerae Inaba by both methods. Conclusions: It was determined that Lactobacillus spp. isolated from ‘tocosh’ presented an antagonistic effect against the reference enteropathogenic bacteria that cause diarrheal diseases.

Según la OMS las enfermedades diarreicas (EDAS) son la segunda causa de muerte en niños menores de cinco años a nivel mundial. Desde la época incaica el ‘tocosh’ es caracterizado por poseer propiedades nutraceúticas. La presente investigación tuvo como Objetivo: Evaluar el efecto antagónico de Lactobacillus spp. aislados de ‘tocosh’ - Solanum sp. proveniente de Huánuco, frente a bacterias enteropatógenas: Escherichia coli enteropatógena (EPEC), Salmonella typhi, Shiguella flexneri y Vibrio cholerae Inaba. Métodos: La población fue extraída del tocosh producido en pozos de fermentación ubicados en la provincia de Yarowilca distrito de Obas, las bacterias fueron aisladas en caldo Man Rogosa Sharpe, en anaerobiosis e incubadas por 48 horas; para purificar las cepas de Lactobacillus spp. se realizaron las pruebas según el manual de Bergey; en la evaluación del efecto antagónico se emplearon los métodos de Burkholder y el método sobrenadante libre de células (CFS), el ensayo se realizó por triplicado a una concentración 2 de la escala de Mac Farland de bacterias lácticas incubándose en aerobiosis a 37 °C por 18 horas. Resultados: De un total de 223 muestras 44 cepas presentaron características microscópicas y bioquímicas compatibles con Lactobacillus spp., las medias de halos de inhibición formados por el método de Burkholder frente a Vibrio cholerae Inaba 1.457.10 (11,36 mm), Salmonella typhi 2.240-16 (9,86 mm), Shiguella flexneri WHO SH-15.3 (6 mm), Escherichia coli enteropatógena (EPEC) 2.734-18 (6 mm) y por el método sobrenadante libre de células se obtuvo medias de Vibrio cholerae Inaba 1.457.10 (13,62 mm), Salmonella typhi 2.240-16 (10,52 mm), Shiguella flexneri WHO SH-15.3 (6,33 mm), Escherichia coli enteropatógena (EPEC) 2.734-18 (6,19 mm). En la comparación de grupos se determinó que el mayor efecto se obtuvo frente a Vibrio cholerae Inaba por ambos métodos. Conclusiones: Se determinó que Lactobacillus spp. aislados de ‘tocosh’ presentó efecto antagónico frente a bacterias enteropatógenas referenciales causantes de EDAS.