Veterinary session

One of the most common human and animal health issues today is the spread of resistance against antimicrobial agents. By using antibiotic alternatives, we can significantly reduce the chance of developing resistance, which has an enormous public health importance. For pigeons there is no antibiotic approved other than ronidazole, yet resistance is spreading. Propolis is an antibacterial, antifungal and antiparasitic natural product, active chemical components such as polyphenols and terpenoids are responsible for its main biological activities. Only the effectiveness of aqueous extract of propolis has been studied worldwide, but its efficacy has been found significantly lower than ethanolic extracts of propolis measured for other protozoa. The efficacy of Hungarian propolis on bacterial and fungal strains isolated from pigeons has not been studied so far. The aim of this study is to determine the in vitro efficacy of different concentrations of ethanolic extracts of propolis from the region „Észak-Alföld” on Staphylococcus spp., Enterococcus spp., Escherichia coli, Salmonella enterica, Trichomonas gallinae, and Candida albicans isolated from pigeons. We are the first who examined the efficacy of ethanolic extracts of propolis on Trichomonas gallinae isolated from pigeons.

We showed that propolis from region „Észak-Alföld” is significantly inhibit the growth of some Gram-positive bacterial strains, moreover, the growth of Candida albicans and Trichomonas gallinae was also hindered. We examined 8-8 types of Candida albicans and bacterial strains. The results of different concentrations of extracts (96%, 90%, 80%, 70%, 60%) - except the 60% ethanolic extract, have not shown significant difference. The MIC values were 12.5-100 µg/ml for Staphylococcus spp. and Enterococcus spp. In E. coli and Salmonella enterica the MIC values were >13 mg/ml. The ethanolic extracts of propolis were active against Candida albicans with MIC values from 3.125 to 50 µg/ml.

The ethanolic extract of propolis from the region „Észak-Alföld” was more effective against Gram-positive (12.5-100 µg/ml), than Gram-negative bacteria (>13 mg/ml), similar to the MIC values described in the literature. In the case of Trichomonas gallinae no comparative literature is available, in our study the propolis concentrations of 1.1-2.5 mg/ml were found to be effective. In vivo studies are recommended to confirm the propolis’ potential use as an alternative antibacterial, antifungal agent and in the treatment of Trichomoas infections.