Antimicrobial activity of Argentinean propolis against Staphylococcus isolated of canine otitis.

Increasing resistance toward the available antibiotics by various microbial diseases pushed veterinarian to think about alternative therapies. Propolis is a natural compound well known since ancient times for its therapeutic effects and has been employed in traditional veterinary medicine. The aim of this study was to analyze the chemical composition of 12 propolis ethanolic extracts (PEEs) from different provinces of Northern Argentina and evaluate their antimicrobial activity against Staphylococcus strains isolated from canine otitis. Thirteen compounds (eight flavonoids, two chalcones and three phenolic acids) were identified by TLC, spectrophotometric methods and HPLC-DAD. PEEs were effective against Staphylococcus strains. The highest antibacterial activities were found in samples from Tucuman province. All propolis samples were considered bacteriostatic and the selection of resistant phenotypes did not occur in presence of Argentinean-PEE. Results of the present study indicate that propolis extracts might be an effective alternative against canine otitis-causing S. aureus strains in vivo.