AbstractThe use of metal complexes to reduce or inhibit virulence factors of Pseudomonas aeruginosa is a promising strategy for the management and control of infections caused by this multidrug-resistant pathogen. The present study aimed to investigate the anti-quorum sensing activity of sub-minimum inhibitory concentrations (sub-MIC) of copper(II) sulfate pentahydrate-curcumin complex (Cu-CUR), iron(III) nitrate nonahydrate -curcumin complex (Fe-CUR), zinc(II) chloride-curcumin complex (Zn-CUR) and free curcumin (free-CUR) against P. aeruginosa PAO1. Metal-CUR complexes were synthesized and characterized by spectroscopic methods. The effect of sub-MIC (1/4 and 1/16 MIC) concentrations of metal-CUR complexes and free-CUR on cell growth, biofilm formation, motility, alginate and pyocyanin production, H2O2 susceptibility and expression of lasI and lasR genes in PAO1 was determined. MIC of metal-CUR complexes and free-CUR was determined as 62.5 and 125 µg/ml, respectively. Metal-CUR complexes at concentration of 62.5 µg/ml significantly reduced the cell growth to 1.5%–3.3%. Although we did not measure the anti-QS activity of metal-CUR complexes directly against PAO1, they indicated anti-QS activity in C. violaceum CV026. Copper-CUR complex at the concentration of 1/4 MIC showed the greatest inhibitory effect on swarming and twitching motilities, biofilm formation, alginate and pyocyanin production, sensitivity to H2O2 and reduction in the expression levels of lasI and lasR genes (P < 0.001). Considering the biological effects of Cu-CUR complex and its inhibitory activity on virulence factors, it may be used as an effective compound for treatment and control of infections caused by P. aeruginosa.
摘要使用金属配合物来减少或抑制铜绿假单胞菌的毒力因子是管理和控制由这种多重耐药病原体引起的感染的一种有前途的策略。本研究旨在研究亚最小抑菌浓度(sub-MIC)的铜(II)硫酸五水合物-姜黄素复合物(Cu-CUR)、铁(III)硝酸九水合物-姜黄素复合物(Fe-CUR)、氯化锌-姜黄素复合物(Zn-CUR)和自由姜黄素(free-CUR)对铜绿假单胞菌PAO1的抗生物感应活性。通过光谱方法合成和表征了金属-CUR复合物。测定了亚-MIC(1/4和1/16 MIC)浓度的金属-CUR复合物和自由-CUR对PAO1的细胞生长、生物膜形成、运动性、藻酸盐和吡咯烷酮产生、H2O2敏感性以及lasI和lasR基因的表达的影响。金属-CUR复合物和自由-CUR的MIC分别为62.5和125 µg/ml。金属-CUR复合物在62.5 µg/ml的浓度下显著降低了细胞生长率,仅为1.5%–3.3%。虽然我们没有直接测量金属-CUR复合物对PAO1的抗生物感应活性,但它们在C. violaceum CV026中表现出了抗生物感应活性。铜-CUR复合物在1/4 MIC的浓度下对游走和抽搐运动、生物膜形成、藻酸盐和吡咯烷酮产生、对H2O2的敏感性以及lasI和lasR基因的表达水平的降低具有最大的抑制作用(P < 0.001)。考虑到铜-CUR复合物的生物学效应和其对毒力因子的抑制活性,它可以作为治疗和控制由铜绿假单胞菌引起的感染的有效化合物。