Discriminating Bacteria with Optical Sensors Based on Functionalized Nanoporous Xerogels

An innovative and low-cost method is proposed for the detection and discrimination of indole-positive pathogen bacteria. The method allows the non-invasive detection of gaseous indole, released by bacteria, with nanoporous colorimetric sensors. The innovation comes from the use of nanoporous matrices doped with 4-(dimethylamino)-cinnamaldehyde, which act as sponges to trap and concentrate the targeted analyte and turn from transparent to dark green, long before the colonies get visible with naked eyes. With such sensors, it was possible to discriminate E. coli from H. alvei, two indole-positive and negative bacteria after seven hours of incubation.

[1]  Tomas Mikoviny,et al.  On-Line Monitoring of Microbial Volatile Metabolites by Proton Transfer Reaction-Mass Spectrometry , 2008, Applied and Environmental Microbiology.

[2]  David R Murdoch,et al.  Detection of volatile metabolites produced by bacterial growth in blood culture media by selected ion flow tube mass spectrometry (SIFT-MS). , 2006, Journal of microbiological methods.

[3]  M. Ammor.  Recent Advances in the Use of Intrinsic Fluorescence for Bacterial Identification and Characterization , 2007, Journal of Fluorescence.

[4]  L. Larsson,et al.  Gas chromatographic comparison of peptone yeast glucose and gas liquid chromatography growth media for anaerobic bacteria , 1987, European Journal of Clinical Microbiology.

[5]  D. Murdoch,et al.  The rapid evaluation of bacterial growth in blood cultures by selected ion flow tube-mass spectrometry (SIFT-MS) and comparison with the BacT/ALERT automated blood culture system. , 2006, Journal of microbiological methods.

[6]  J. Collins,et al.  Bacterial charity work leads to population-wide resistance , 2010, Nature.

[7]  M. McEwan,et al.  Real-time detection of common microbial volatile organic compounds from medically important fungi by Selected Ion Flow Tube-Mass Spectrometry (SIFT-MS). , 2005, Journal of microbiological methods.

[8]  A. Fox.  Mass Spectrometry for Species or Strain Identification after Culture or without Culture: Past, Present, and Future , 2006, Journal of Clinical Microbiology.

[9]  Avijit Sen,et al.  Rapid identification of bacteria with a disposable colorimetric sensing array. , 2011, Journal of the American Chemical Society.

[10]  T. Wood,et al.  Environmental factors affecting indole production in Escherichia coli. , 2011, Research in microbiology.

[11]  I. Pastan,et al.  Stimulation of tryptophanase synthesis in Escherichia coli by cyclic 3',5'-adenosine monophosphate. , 1969, The Journal of biological chemistry.

[12]  J. Perry,et al.  Identification of volatile organic compounds produced by bacteria using HS-SPME-GC-MS. , 2014, Journal of chromatographic science.

[13]  Ubonrat Siripatrawan.  Rapid differentiation between E. coli and Salmonella Typhimurium using metal oxide sensors integrated with pattern recognition , 2008 .

[14]  Achim Kohler,et al.  FT-IR spectroscopy for identification of closely related lactobacilli. , 2004, Journal of microbiological methods.

[15]  David R Murdoch,et al.  The rapid evaluation of bacterial growth and antibiotic susceptibility in blood cultures by selected ion flow tube mass spectrometry. , 2006, Diagnostic microbiology and infectious disease.

[16]  L. Bret,et al.  Indole can act as an extracellular signal to regulate biofilm formation of Escherichia coli and other indole-producing bacteria. , 2003, Canadian journal of microbiology.

[17]  Jintae Lee,et al.  Indole as an intercellular signal in microbial communities. , 2010, FEMS microbiology reviews.