Antibacterial Activity of Propolis Ethanol Extract against Antibiotic Resistance Bacteria Isolated from Burn Wound Infections

Burn wound is a suitable site for incidence of resistant infections; thus, the research for finding effective drugs against this infection is necessary. The purpose of this study was to determine antibacterial activity of Isfahan bee propolis extracts against beta-lactamase producing bacteria isolated from burn wound infections. Ethanol extract of Isfahan bee propolis was prepared by 28 g of propolis in 100 ml of 70% ethanol. Antibacterial activity of ethanol extracts were evaluated against beta-lactamase producing bacteria (Staphylococcus aureus and Pseudomonas aeruginosa) isolated of burn wound infection by well diffusion method. Broth serial dilution method was used to determine MBC of extract. Beta-lactamase production of isolates was detected by iodometric test, imipenem-EDTA combined disk test and imipenem-EDTA double-disk synergy test. Ethanol extract of propolis was found to be the most effective against S. aureus strains (inhibition zone=17.66±0.47 mm) than P. aeruginosa strains (inhibition zone=7 mm). The MIC and MBC values of the extracts against S. aureus strains were 0.0143 and 0.0286 mg/ml and these values against P. aeruginosa strains were 0.75 and 1.5 mg/ml, respectively. Among the S. aureus clinical isolates, all of strains produced beta-lactamase. Imipenem-EDTA double-disk synergy test showed that only one clinical isolate of P. aeruginosa was metallo-beta-lactamase positive. This study demonstrated that ethanol extract of Isfahan bee propolis is mainly active against S. aureus and it is effective on P. aeruginosa at higher concentration. Ethanol extract of propolis did not inhibit production of beta-lactamase enzyme in tested bacteria.