Resultado da pesquisa (1)

Termo utilizado na pesquisa Sant’ana AS

#1 - Antimicrobial activity of plant extracts and compounds over resistant Gram-negative isolates from domestic animals

Abstract in English:

Gram-negative bacteria present significant challenges due to their antimicrobial resistance. Members of the Enterobacterales order, such as Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis, pose the greatest risk to public health because of their numerous mechanisms of antimicrobial resistance. Therefore, this study aimed to evaluate the antimicrobial activity of crude ethanolic extracts (CEE) of Hymenaea martiana Hayne (jatobá), Commiphora leptophloeos (Mart.) Gillett (imburana), Ocimum campechianum Mill. (alfalvaca) and Morus nigra L. (amora miura), as well as the hexane and ethyl acetate fractions of the last one, against clinical isolates of Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis obtained from domestic animals. Furthermore, three commercially available compounds – gallic acid (GA), p-Coumaric acid (p-CA), benzoic acid (BA) – and one conducting polymer (synthesized for the test), polypyrrole (Ppy), were also evaluated for their antimicrobial potential against these isolates. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extracts and compounds were determined. All E. coli and K. pneumoniae isolates were resistant to the tested extracts. The crude ethanolic extracts showed inhibitory activity against P. mirabilis isolates at concentrations of 3,125 µg/mL for H. martiana and 12,500 µg/mL for O. campechianum. However, C. leptophloeos, M. nigra, and their fractions (hexane and ethyl acetate), as well as GA, did not exhibit bactericidal activity against any of the pathogens. Benzoic acid demonstrated both inhibitory and bactericidal activity against all isolates, with pronounced bactericidal activity against two K. pneumoniae isolates (MBC of 2,000 µg/mL). p-Coumaric acid showed inhibitory activity against all isolates and bactericidal activity (MBC of 5,000 µg/mL) against 66.66% (4/6) of the isolates, proving effective against E. coli and K. pneumoniae. Polypyrrole exhibited the most potent antibacterial activity, inhibiting 100% of the isolates and showing bactericidal activity against 83.33% (5/6) of the clinical isolates tested. These results suggest that the tested extracts and compounds, particularly polypyrrole, may offer a viable alternative against multidrug-resistant microorganisms.

Abstract in Portuguese:

Gram-negative bacteria present significant challenges due to their antimicrobial resistance. Members of the Enterobacterales order, such as Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis, pose the greatest risk to public health because of their numerous mechanisms of antimicrobial resistance. Therefore, this study aimed to evaluate the antimicrobial activity of crude ethanolic extracts (CEE) of Hymenaea martiana Hayne (jatobá), Commiphora leptophloeos (Mart.) Gillett (imburana), Ocimum campechianum Mill. (alfalvaca) and Morus nigra L. (amora miura), as well as the hexane and ethyl acetate fractions of the last one, against clinical isolates of Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis obtained from domestic animals. Furthermore, three commercially available compounds – gallic acid (GA), p-Coumaric acid (p-CA), benzoic acid (BA) – and one conducting polymer (synthesized for the test), polypyrrole (Ppy), were also evaluated for their antimicrobial potential against these isolates. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extracts and compounds were determined. All E. coli and K. pneumoniae isolates were resistant to the tested extracts. The crude ethanolic extracts showed inhibitory activity against P. mirabilis isolates at concentrations of 3,125 µg/mL for H. martiana and 12,500 µg/mL for O. campechianum. However, C. leptophloeos, M. nigra, and their fractions (hexane and ethyl acetate), as well as GA, did not exhibit bactericidal activity against any of the pathogens. Benzoic acid demonstrated both inhibitory and bactericidal activity against all isolates, with pronounced bactericidal activity against two K. pneumoniae isolates (MBC of 2,000 µg/mL). p-Coumaric acid showed inhibitory activity against all isolates and bactericidal activity (MBC of 5,000 µg/mL) against 66.66% (4/6) of the isolates, proving effective against E. coli and K. pneumoniae. Polypyrrole exhibited the most potent antibacterial activity, inhibiting 100% of the isolates and showing bactericidal activity against 83.33% (5/6) of the clinical isolates tested. These results suggest that the tested extracts and compounds, particularly polypyrrole, may offer a viable alternative against multidrug-resistant microorganisms.


Colégio Brasileiro de Patologia Animal SciELO Brasil CAPES CNPQ UFRRJ CFMV