Aspergillus ochraceopetaliformis SSP13 modulates quorum sensing regulated virulence and biofilm formation in Pseudomonas aeruginosa PAO1

Abstract

Pseudomonas aeruginosa is an opportunistic nosocomial pathogen causing the majority of acute and persistent infections in human beings. The ability to form biofilm adds a new dimension to its resistance to conventional therapeutic agents. In the present study, down-regulation of quorum sensing regulated virulence and biofilm development resulting from exposure to Aspergillus ochraceopetaliformis SSP13 extract was investigated. The in vitro results inferred impairment in the production of LasA protease, LasB elastase, chitinase, pyocyanin, exopolysaccharides and rhamnolipids. In addition, motility and biofilm formation by P. aeruginosa PAO1 was significantly altered. The in vitro results were further supported by molecular docking studies of the metabolites obtained from GC-MS analysis depicting the quorum sensing attenuation by targeting the receptor proteins LasR and RhlR. The in vitro and in silico studies suggested new avenues for the development of bioactive metabolites from A. ochraceopetaliformis SSP13 extract as potential anti-infective agents.

Keywords:

• Quorum sensing
• biofilm
• Pseudomonas aeruginosa
• Aspergillus ochraceopetaliformis
• HPTLC
• molecular docking

Acknowledgements

The authors acknowledge the support of Dr G. Muralitharan, Department of Microbiology, Bharathidasan University for the CLSM analysis. The authors would also like to acknowledge the Central Instrumentation Facility (CIF), Pondicherry University, Pondicherry for the HPTLC analysis. The authors also thank the Department of Biotechnology (6242-P104/RGCB/PMD/DBT/ADRO/2015), Government of India, for financial assistance in purchasing a workstation for carrying out the in silico work.

Conflict of interest

All the authors hereby declare no conflict of interest.