Revista argentina de microbiología
versión On-line ISSN 1851-7617
This study assessed the susceptibility of Escherichia coli to the antimicrobial activity of honeys by different techniques. Honeys used were from the southeast region of Buenos Aires province. In order to evaluate antimicrobial activity against Escherichia coli ATCC 25922, solutions containing 0, 1, 5, 10, 25 and 50% (w/v) of honey were prepared. Liquid media (Mueller-Hinton and Mac Conkey broths) were used to assess the Minimal Inhibitory Concentration (MIC) by the serial dilution test. The minimal bactericidal concentration (MBC) was determined by counting on nutritive and Mac Conkey agar. In addition, for the evaluation of total antibacterial activity, the agar diffusion method was used. A reduction of microbial growth of 96% in Mueller-Hinton broth and of 90% in Mac Conkey broth by honey solutions containing 50% and 25% (w/v), was respectively observed. The bactericide action of honey in nutritive agar proved negative. The MBC value in Mac Conkey agar was 25% (w/v) of honey. The methods used for measuring the antibacterial activity in the present work were adequate to prove that honeys are active against E. coli at 25 and 50% (w/v) concentrations. The results obtained by the dilution method with Mueller- Hinton broth and the agar diffusion method were both concordant.
Palabras clave : Escherichia coli; Honey; Antibacterial activity.