Evaluación in vitro del efecto antibacteriano de los extractos de Bidens pilosa L. y Eryngium foetidum L.

Abstract

The objective of the study was to evaluate the in vitro antimicrobial effect of the ethanolic extracts of Bidens pilosa and Eryngium foetidum on Staphylococcus aureus, Escherichia coli and Salmonella Typhimurium. The highest yield percentage was with Bidens pilosa leaves (1.3±0.12) and for Eryngium foetidum (0.21±0.04%) in the month of November. Preliminary phytochemical analysis revealed the presence of some secondary alkaloid metabolites, glycosides, saponins, sterols, flavonoids, and tannins. Concentrations of 5, 10 and 15 mg/ml were evaluated in 98% ethanol dilution. The Minimum Inhibitory Concentration (MIC) will be prolonged by means of the diffusion method and dilution in agar. The bacterial inoculum was standardized at 0.5 of the MacFarland scale in a spectrophotometer, obtaining as a result that the concentrations of 15 mg/ml did not present inhibition halos, being the concentration at 10 mg/ml of Eryngium foetidum extract the one that presented the greatest halo. of inhibition (21.0 ± 2.0) for Staphylococcus aureus. In the Minimum Bactericidal Concentration (MBC) concentrations of 250, 125, 62.5 and 31.25 mg/ml were evaluated, the CMB was presented from the concentration of 15.62 for Staphylococcus aureus with Eryngium foetidum while the highest concentration was obtained for Bidens pilosa with 125 mg/ml in Escherichia coli and Salmonella Typhimurium. The antimicrobial susceptibility test shows that all concentrations appeared antimicrobial susceptibility. On the other hand, the results for Eryngium foetidum show the minimum concentration of 62.5 mg/ml in the strain of E. coli and Salmonella Typhimurium