title: Identification of natural compounds which inhibit biofilm formation in clinical isolates of Klebsiella pneumoniae.
abstract: Klebsiella pneumoniae, an important opportunistic pathogen, exists as a biofilm in persistent infections and in-dwelling medical devices. With the objective of identifying natural compounds inhibiting biofilm formation in K. pneumoniae, 35 clinical isolates were screened,out of which 7 strong biofilm producers were identified. Six natural compounds were tested for their inhibitory effects on bacterial growth and biofilm formation by determining the minimum inhibitory concentration and minimum concentration for biofilm inhibition (MBIC) for each compound. The results show that reserpine followed by linoleic acid, were the most potent biofilm inhibitors. Reserpine, an efflux pump inhibitor was effective at biofilm inhibition at a concentration of 0.0156 mg/mL, 64-fold lower concentration than its MIC. Linoleic acid, an essential fatty acid was effective as a biofilm inhibitor at 0.0312 mg/mL, which is 32-fold lower than its MIC. Berberine, another plant derived antimicrobial, chitosan and eugenol had an MBIC value of 0.0635 mg/mL. Curcumin, a natural phenolic compound was effective at biofilm inhibition at a concentration of 0.25 mg/mL, which is 50 fold less than its MIC. Notably, the MIC and MBIC data on these 6 natural compounds was reproducible in all seven high biofilm forming isolates of K. pneumoniae. The present report is a comprehensive comparative analysis of the dose dependent inhibition of various natural compounds on biofilm formation in K. pneumoniae.
authors.affiliation: Department of Biotechnology, Dr. M.G.R.Educational and Research Institute, E.V.R. Periyar Salai, Maduravoyal, Chennai 600 095, India.
authors.forename: H
authors.initials: H
authors.lastname: Magesh
authors.affiliation: Department of Biotechnology, Dr. M.G.R.Educational and Research Institute, E.V.R. Periyar Salai, Maduravoyal, Chennai 600 095, India.
authors.forename: Arun
authors.initials: A
authors.lastname: Kumar
authors.affiliation: Department of Biotechnology, Dr. M.G.R.Educational and Research Institute, E.V.R. Periyar Salai, Maduravoyal, Chennai 600 095, India.
authors.forename: Ayesha
authors.initials: A
authors.lastname: Alam
authors.affiliation: Department of Biotechnology, Dr. M.G.R.Educational and Research Institute, E.V.R. Periyar Salai, Maduravoyal, Chennai 600 095, India.
authors.lastname: Priyam
authors.affiliation: Department of Microbiology, Sri Ramachandra University, Porur, Chennai 600 116, India.
authors.forename: Uma
authors.initials: U
authors.lastname: Sekar
authors.affiliation: Bhupat & Jyothi Mehta School of Biosciences, Indian Institute of Technology, Chennai 600 036, India.
authors.forename: Venil N
authors.initials: VN
authors.lastname: Sumantran
authors.affiliation: Department of Biotechnology, Dr. M.G.R.Educational and Research Institute, E.V.R. Periyar Salai, Maduravoyal, Chennai 600 095, India.
authors.forename: Rama
authors.initials: R
authors.lastname: Vaidyanathan
mesh_terms: D018441:Biofilms / Q000187:drug effects*; D001688:Biological Products / Q000494:pharmacology*; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology; D008826:Microbial Sensitivity Tests
chemical_list: D001688:Biological Products