Proving the antimicrobial spectrum of an amphoteric surfactant-sol-gel coating: a food-borne pathogen study

J Ind Microbiol Biotechnol. 2008 Sep;35(9):1041-6. doi: 10.1007/s10295-008-0380-3. Epub 2008 Jun 7.

Abstract

An antimicrobial coating was evaluated in this work for its antimicrobial efficacy against common food-borne pathogens. Dodecyl-di(aminoethyl)-glycine, an organic disinfectant, was immobilized in a silicon oxide matrix to generate thin films over surfaces by means of the sol-gel process. Tetraethoxysilane was used as the polymeric precursor. No alteration of optical transparency on the covered surfaces was observed. Topographic images obtained with atomic force microscopy showed a homogeneous film with no additional roughness added by the polymer to the surface. The attenuated total reflectance-Fourier transform infrared spectral data showed the presence of dodecyl-di(aminoethyl)-glycine in the silicon oxide network after a normal cleaning procedure. The antimicrobial efficacy test was performed by exposing coated slides to suspensions of common food-borne pathogens: Escherichia coli, Staphyloccocus aureus, E. coli O157:H7, Salmonella typhi, S. cholerasuiss, Listeria innocua and L. monocytogenes. The coating activity was not only bacteriostatic but also bactericidal. The percent reduction of viable microorganism exposure over 24 h to the coated surface ranged between 99.5%, for the more resistant gram-positive bacteria, and over 99.999%, for most gram-negative bacteria. The silicon matrix itself did not account for any reduction of viable microbial, even more an increase was observed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Infective Agents / chemistry
  • Anti-Infective Agents / pharmacology*
  • Bacteria / drug effects*
  • Colony Count, Microbial
  • Disinfectants / chemistry
  • Disinfectants / pharmacology*
  • Food Industry / methods
  • Food Microbiology*
  • Gels / chemistry
  • Gels / pharmacology*
  • Glycine / analogs & derivatives*
  • Glycine / chemistry
  • Glycine / pharmacology
  • Microscopy, Atomic Force
  • Spectrophotometry, Infrared
  • Spectrophotometry, Ultraviolet
  • Surface-Active Agents / chemistry
  • Surface-Active Agents / pharmacology*

Substances

  • Anti-Infective Agents
  • Disinfectants
  • Gels
  • Surface-Active Agents
  • dodicin
  • Glycine