Appraisal Of Micronutrients on Quorum Sensing Bacteria

Abstract

“Quorum sensing” mediated ‘biofilm’ stability and functionality among Bacteria involves expressing small diffusible signal molecules called auto-inducers that negatively impact human health during bacterial infections by contributing virulence and pathogenicity. Further, this leads to multidrug resistance among various bacterial species, making fighting infections difficult. Therefore, understanding and regulating molecular mechanisms of quorum sensing signals help combat such bacterial infections via Quorum quenching. Several micronutrients play a vital role in health maintenance and hence can be effective Quorum quenchers. The current investigation tests the effect of vitamin C, vitamin E, Folic acid, and Fisetin at various concentrations ranging from 4.87 to 300μg/ml against Escherichia coli, Pseudomonas aeruginosa and from 0.62 to 100ug/ml against Chromobacterium violaceum by agar-diffusion, MTT[3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide), Biofilm inhibition, and Violacein pigment inhibition assays. Our results indicated that agar well-diffusion assay showed no significant inhibition effects against the tested organisms.  However, in the MTT assay, Vitamin C was cytotoxic against E. coli, Vitamin E against P. aeruginosa and C. violaceum, and both folic acid and Fisetin against E. coli and C. violaceum. Furthermore, Vitamin E was found to be the effective inhibitor of biofilm formation (20.32%) followed by Fisetin (7.2%), Folic acid (6.25%), and Vitamin C (4.69%) respectively. Vitamin E (<0.01) and Fisetin (<0.05) inhibited Violacein pigment production in C. violaceum. Overall, these results suggest the potential application of vitamins and dietary antioxidants as effective quorum-sensing inhibitors and to develop novel anti-virulence therapies.