Gupta P, Sarkar A, Sandhu P, Daware A, Das M C, Akhter Y, Bhattacharjee S
Department of Molecular Biology and Bioinformatics, Tripura University (A Central University), Suryamaninagar, Tripura, India.
Centre for Computational Biology and Bioinformatics, School of Life Sciences, Central University of Himachal Pradesh, Shahpur, Himachal Pradesh, India.
J Appl Microbiol. 2017 Jul;123(1):246-261. doi: 10.1111/jam.13476.
Pseudomonas aeruginosa is one of the fatal biofilm-forming pathogens which pose to be a problem in clinical infections, contamination of food and marine ecosystems. In this report, a naphthoquinone-plumbagin has been explored for its antimicrobial (antibacterial and antibiofilm) activity against P. aeruginosa biofilm. The ability of plumbagin to enhance the bioactivity of a known broad-spectrum antibiotic was further assayed by combining the sub-MIC doses of plumbagin with sub-MIC doses of gentamicin against P. aeruginosa biofilm.
This combinatorial approach was used for a series of experiments for understanding the mechanism of action for antibiofilm activity against P. aeruginosa (MTCC 424, MTCC 2488). Antibiofilm activity was studied by safranin staining, estimating total protein, visualization of biofilms and extra polymeric substances quantification. Antivirulent activity of these doses was studied by azocasein degradation, expression of virulent factors and molecular docking. Expression of quorum sensing (QS) phenotypes was studied by motility assessment and mRNA expression pattern of virulence genes. It was observed that plumbagin alone and the combinatorial doses of plumbagin and gentamicin exhibit significant antibiofilm and antivirulent activity coupled with the reduction in the expression of QS phenotypes and virulence genes. Molecular docking study revealed that plumbagin had variable affinity for different QS proteins.
Low doses of plumbagin and gentamicin exhibit synergistic activity against P. aeruginosa biofilm while maintaining their effectiveness.
As the P. aeruginosa biofilms are reservoir of persister bacteria, thus, the increasing concern of antibiotic tolerance has to be dealt with combinatorial approaches. In this report, plumbagin has been explored in potentiating the antibiofilm effect of a broad-spectrum antibiotic gentamicin for better therapeutic efficacy.
铜绿假单胞菌是一种致命的形成生物膜的病原体，在临床感染、食品污染和海洋生态系统中构成问题。在本报告中，研究了萘醌类化合物白花丹素对铜绿假单胞菌生物膜的抗菌（抗菌和抗生物膜）活性。通过将亚抑菌剂量的白花丹素与亚抑菌剂量的庆大霉素联合用于铜绿假单胞菌生物膜，进一步测定了白花丹素增强已知广谱抗生素生物活性的能力。
采用这种组合方法进行了一系列实验，以了解针对铜绿假单胞菌（MTCC 424、MTCC 2488）的抗生物膜活性作用机制。通过番红染色、总蛋白估计、生物膜可视化和胞外聚合物定量研究抗生物膜活性。通过偶氮酪蛋白降解、毒力因子表达和分子对接研究这些剂量的抗毒力活性。通过运动性评估和毒力基因的mRNA表达模式研究群体感应（QS）表型的表达。观察到单独的白花丹素以及白花丹素和庆大霉素的组合剂量表现出显著的抗生物膜和抗毒力活性，同时降低了QS表型和毒力基因的表达。分子对接研究表明，白花丹素对不同的QS蛋白具有可变亲和力。
低剂量的白花丹素和庆大霉素对铜绿假单胞菌生物膜表现出协同活性，同时保持其有效性。
由于铜绿假单胞菌生物膜是持续存在细菌的储存库，因此，对抗生素耐受性日益增加的关注必须通过组合方法来解决。在本报告中，已研究白花丹素增强广谱抗生素庆大霉素的抗生物膜作用以获得更好的治疗效果。
