Biofilm inhibitory effect of chlorhexidine conjugated gold nanoparticles against Klebsiella pneumoniae.
Klebsiella pneumoniae (K. pneumoniae) is one of the major pathogen associated with nosocomial infections, especially catheter associated urinary tract infections which involved biofilm formation. This study was designed to evaluate the antibiofilm efficacy of gold nanoparticle conjugated with chlorhexidine (Au-CHX) against K. pneumoniae isolates. Au-CHX was synthesized and analyzed for stability by using UV-Visible spectrophotometry, atomic force microscopy (AFM), fourier transform infrared spectroscopy (FT-IR) and electrospray ionization mass spectroscopy (ESI-MS). Biofilm inhibition and eradication was performed by crystal violet, 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays and further confirmed by florescence and AFM microscopy. Au-CHX showed the maxima surface plasmon resonance (SPR) band at 535 nm, spherical morphology and polydispersity with size in the range of 20-100 nm. The micro molar concentrations (i.e. 25 and 100 μM) of Au-CHX completely inhibited the biofilm formation and metabolic activity within biofilms of K. pneumoniae reference and three tested clinical isolates, respectively. Time dependant biofilm inhibition assay showed that Au-CHX inhibited the early stage of biofilm formation. While at 75 and 100 μM concentrations, it also eradicated the established biofilms of K. pneumoniae isolates as compared to 2 mM chlorhexidine. Reduced florescence signals and surface roughness during microscopic analysis further confirms the antibiofilm activity of Au-CHX against K. pneumoniae ATCC13882 and clinical isolates. Thus it is concluded that chlorhexidine coated gold nanoparticle not only inhibits the biofilm formation of K. pneumoniae ATCC and clinical isolates but also eradicated the preformed biofilm.
Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences (ICCBS), University of Karachi, Karachi, 75270, Pakistan. Electronic address: jabees2003@hotmail.com.
Ayaz
A
Ahmed
Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences (ICCBS), University of Karachi, Karachi, 75270, Pakistan.
Anum Khalid
AK
Khan
H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences (ICCBS), University of Karachi, Karachi, 75270, Pakistan.
Ayaz
A
Anwar
H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences (ICCBS), University of Karachi, Karachi, 75270, Pakistan.
Syed Abid
SA
Ali
H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences (ICCBS), University of Karachi, Karachi, 75270, Pakistan. Electronic address: raza_shahm@yahoo.com.
Muhammad Raza
MR
Shah
D018441:Biofilms / Q000187:drug effects*; D002710:Chlorhexidine / Q000737:chemistry / Q000494:pharmacology*; D004202:Disinfectants / Q000737:chemistry / Q000494:pharmacology*; D005562:Formazans / Q000032:analysis; D005840:Gentian Violet / Q000032:analysis; D006046:Gold / Q000737:chemistry / Q000494:pharmacology*; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000502:physiology; D018625:Microscopy, Atomic Force; D008856:Microscopy, Fluorescence; D053758:Nanoparticles / Q000737:chemistry / Q000382:microbiology* / Q000648:ultrastructure; D021241:Spectrometry, Mass, Electrospray Ionization; D013053:Spectrophotometry; D017550:Spectroscopy, Fourier Transform Infrared; D013194:Staining and Labeling; D020349:Surface Plasmon Resonance; D013778:Tetrazolium Salts / Q000032:analysis
D004202:Disinfectants; D005562:Formazans; D013778:Tetrazolium Salts; C079782:MTT formazan; D006046:Gold; D005840:Gentian Violet; D002710:Chlorhexidine
Antibiofilm; Atomic force microscopy; Chlorhexidine; Gold nanoparticles; Klebsiella pneumoniae