Phytocompounds against uropathogens: Antibacterial and antifungal activities of Nelumbo nucifera Gaertn. methanolic extract against selected biofilm-forming pathogens

Uropathogens including bacteria and fungi are responsible for several diseases including nosocomial infections like catheter-associated urinary tract infections (CAUTI).When CAUTIs are caused by biofilms on catheter surfaces by multidrug-resistant microorganisms, it creates mild to severe complications due to their complex structure making the treatment and management challenging.Even though, there are many chemical catheter coating agents available, the researchers are looking for potential phytocompounds to be developed as coating agents as the micro-organisms find it difficult to develop resistance against them due to many reasons including the modes of action like targeting multiple sites in microbial cells.Thus, the present investigation analyses the antibiofilm and antimicrobial potentials of a plant, Nelumbo nucifera Gaertn.against CAUTI-causing organisms like Enterococcus faecalis, Escherichia coli, Candida albicans, and Staphylococcus aureus.Antimicrobial activities of the methanolic extract of the herb were tested by agar diffusion method and the minimal inhibitory concentration of the extract was found to be 0.5 mg/ml for S. aureus, 1 mg/ml each for E. faecalis, E. coli, and 2 mg/ml for C. albicans.The antibiofilm potential of N. nucifera was studied quantitatively by biofilm inhibition assay, and the extract successfully eliminated the mature biofilms of S. aureus, E. faecalis, C. albicans, and E. coli, and by 83%, 87%, 89%, and 83%, respectively.The activity of the extract as a catheter coating agent against all the test pathogens was also proved positively using an in vitro bladder model.The plant extract also showed promising antioxidant properties and when performing MTT assay using L 929 cells.It was proven that the extract possesses no cytotoxic effect.So, the authors recommend further detailed studies to explore the chances of using N. nucifera based phytocompounds as a better alternative in the treatment of CAUTI and to be used as a catheter coating agent to prevent biofilm formation.