Abstract Propolis could represent an alternative therapeutic agent for targeting multidrug-resistant bacteria due to its antimicrobial potential. The effect of Brazilian green propolis (BGP) aqueous extract (AqExt) was evaluated on eight multidrug-resistant clinical strains of Klebsiella pneumoniae and Pseudomonas aeruginosa, as well as on one reference strain for each bacterial species. The minimum bactericidal concentration (MBC) was determined and optimal concentrations were further evaluated in comparison with 0.12% chlorhexidine. The natural extract was chemically characterized by HPLC-DAD analysis. The MBC values ranged between 3.12 and 27.5 mg ml−1. Analysis of bacterial metabolic activity after treatment for 5 min with BGP-AqExt revealed a strong antimicrobial potential, similar to chlorhexidine. The extract comprised several active compounds including quercetin, gallic acid, caffeic and p-coumaric acid, drupani, galangin, and artepillin C. Altogether, the findings suggest that BGP-AqExt is fast and effective against multidrug-resistant strains of K. pneumoniae and P. aeruginosa in planktonic cultures and biofilms.

中文翻译：

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巴西绿蜂胶提取物对肺炎克雷伯菌和铜绿假单胞菌多重耐药菌株浮游细胞和生物膜的影响

摘要 由于其抗菌潜力，蜂胶可以成为靶向多重耐药细菌的替代治疗剂。评估了巴西绿蜂胶 (BGP) 水提取物 (AqExt) 对肺炎克雷伯菌和铜绿假单胞菌的八种多重耐药临床菌株以及每种细菌物种的一种参考菌株的影响。确定了最低杀菌浓度 (MBC)，并与 0.12% 洗必泰进行了比较，进一步评估了最佳浓度。通过 HPLC-DAD 分析对天然提取物进行化学表征。MBC 值介于 3.12 和 27.5 mg ml-1 之间。用 BGP-AqExt 处理 5 分钟后对细菌代谢活性的分析显示出与氯己定相似的强大抗菌潜力。