In vitro and in silico attenuation of quorum sensing mediated pathogenicity in Pseudomonas aeruginosa using Spirulina platensis.

Biofilm forming pathogenic bacteria showing resistance towards antimicrobial agents has increased the urge to find an alternative treatment strategy. Among the biofilm forming pathogenic bacteria, Pseudomonas aeruginosa is a well-recognised Gram negative biofilm former causing nosocomial infection and other disease among immunocompromised patients. The aim of the current study is to evaluate the antipathogenic potentials of S. platensis against P. aeruginosa. S. platensis methanolic extract (SME) inhibited the biofilm (89%), extracellular polymeric substances (EPS), cell surface hydrophobicity (CSH) (44%), pyocyanin, pyoveridin and swarming motility of P. aeruginosa. Partial purification of SME using thin layer chromatography (TLC), column chromatography and gas chromatography mass spectroscopy (GCMS) revealed the major component as hexadecanoic acid (HxD). Further analysis through in silico approach showed the efficient binding of HxD with the biofilm regulatory proteins (Las R and salidase enzyme) of P. aeruginosa. The coating of HxD over different material surfaces efficiently prevented the adhesion of P. aeruginosa biofilm. The results of the toxicity assay revealed that the SME is non-toxic towards Artemia salina at the given concentration. Hence the overall work proves the potential non-toxic effects of SME against P. aeruginosa pathogenicity.