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Examination of nanoparticle inactivation of C ampylobacter jejuni biofilms using infrared and R aman spectroscopies
Author(s) -
Lu X.,
Weakley A.T.,
Aston D.E.,
Rasco B.A.,
Wang S.,
Konkel M.E.
Publication year - 2012
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/j.1365-2672.2012.05373.x
Subject(s) - biofilm , campylobacter jejuni , extracellular polymeric substance , microbiology and biotechnology , chemistry , raman spectroscopy , reactive oxygen species , biophysics , bacteria , biology , biochemistry , genetics , physics , optics
Aims To investigate inactivation effect and mechanism of zinc oxide nanoparticles ( Z n O NP s) activity against C ampylobacter jejuni biofilms. Methods and Results Z n O NP s with concentrations of 0, 0·6, 1·2 and 6 mmol l −1 were employed in antimicrobial tests against C amp. jejuni planktonic cells and biofilms. C ampylobacter jejuni sessile cells in biofilms were more resistant to a low concentration of Z n O NP s when compared to planktonic cells. The Z n O NP s penetrated the extracellular polymeric substance ( EPS ) without damage to the EPS and directly interacted with the sessile bacterial cells, as determined using infrared spectroscopy and scanning electron microscopy. Raman spectroscopy shows alterations in quinone structures and damage to nucleic acids following Camp. jejuni treatment with Z n O NP s. The mechanism of DNA damage is most likely due to the generation of reactive oxygen species ( ROS ). Spectroscopic‐based partial least squares regression ( PLSR ) models could predict the number of surviving sessile cell numbers within a bacterial biofilm (≥log 4 CFU , root mean square error of estimation <0·36) from F ourier transform infrared ( FT ‐ IR ) spectral measurements. Conclusions Z n O NP s were found to have antimicrobial activity against C amp. jejuni biofilms. Z n O NP s penetrated the biofilm EPS within 1 h without damaging it and interacted directly with sessile cells in biofilms. Alterations in the DNA / RNA bases, which are owing to the generation of ROS , appear to result in Camp. jejuni cell death. Significance and Impact of the Study ZnO NP s may offer a realistic strategy to eliminate C amp. jejuni biofilms in the environment.