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Interaction of A l 2 O 3 nanoparticles with E scherichia coli and their cell envelope biomolecules
Author(s) -
Ansari M.A.,
Khan H.M.,
Khan A.A.,
Cameotra S.S.,
Saquib Q.,
Musarrat J.
Publication year - 2014
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1111/jam.12423
Subject(s) - cell envelope , transmission electron microscopy , bacterial cell structure , chemistry , escherichia coli , biomolecule , fourier transform infrared spectroscopy , biophysics , nanoparticle , nuclear chemistry , membrane , cell membrane , bacteria , materials science , biochemistry , nanotechnology , chemical engineering , biology , genetics , engineering , gene
Aims The aim of this study is to investigate the antibacterial activity of aluminium oxide nanoparticles (Al 2 O 3 NP s) against multidrug‐resistant clinical isolates of E scherichia coli and their interaction with cell envelope biomolecules. Methods and Results Al 2 O 3 NP s were characterized by scanning electron microscope ( SEM ), high‐resolution transmission electron microscope ( HR ‐ TEM ) and X ‐ray diffraction ( XRD ) analyses. Antibacterial activity and interaction of Al 2 O 3 NP s with E. coli and its surface biomolecules were assessed by spectrophotometry, SEM , HR ‐ TEM and attenuated total reflectance/Fourier transform infrared ( ATR ‐ FTIR ). Of the 80 isolates tested, about 64 (80%) were found to be extended spectrum β ‐lactamase ( ESBL ) positive and 16 (20%) were non‐ ESBL producers. Al 2 O 3 NP s at 1000 μ g ml −1 significantly inhibited the bacterial growth. SEM and HR ‐ TEM analyses revealed the attachment of NP s to the surface of cell membrane and also their presence inside the cells due to formation of irregular‐shaped pits and perforation on the surfaces of bacterial cells. The intracellular Al 2 O 3 NP s might have interacted with cellular biomolecules and caused adverse effects eventually triggering the cell death. ATR ‐ FTIR studies suggested the interaction of lipopolysaccharide ( LPS ) and L ‐ α ‐ P hosphatidyl‐ethanolamine ( PE ) with Al 2 O 3 NP s. Infrared ( IR ) spectral changes revealed that the LPS could bind to Al 2 O 3 NP s through hydrogen binding and ligand exchange. The A l 2 O 3 NP s‐induced structural changes in phospholipids may lead to the loss of amphiphilic properties, destruction of the membrane and cell leaking. Conclusions The penetration and accumulation of NP s inside the bacterial cell cause pit formation, perforation and disorganization and thus drastically disturb its proper function. The cell surface biomolecular changes revealed by ATR ‐ FTIR spectra provide a better understanding of the cytotoxicity of Al 2 O 3 NP s. Significance and Impact of the Study Al 2 O 3 NP s may serve as broad‐spectrum bactericidal agents to control the emergent pathogens regardless of their drug‐resistance mechanisms.