ARS | Publication request: Use of photopolymerization for the rapid and cost-effective identification of Shiga toxin-producing Escherichia coli on DNA microarrays

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 4, 2010
Publication Date: N/A

Technical Abstract: Shiga toxin-producing Escherichia coli O157:H7 is a leading cause of foodborne illness worldwide. To evaluate better methods to rapidly detect and genotype E. coli O157 virulent strains, the present study explored the use of photopolymerization, a colorimetric and photoinduced signal amplification detection method, for pathogen identification on DNA microarrays. A DNA oligonucleotide microarray was designed to target O157 genetic markers encoding Shiga toxin production, and adherence and O-antigen factors. Analysis of the microarray data demonstrated polymer formation for only probes targeting virulence genes present in the tested E. coli O157 reference strains RM1625, RM1600, RM6011, and RM4876. Positive hybridization signals had average signal-to-noise ratio values above 10, while signal-to-noise ratio values below 1.5 were determined for the same virulence probes in the non-pathogenic E. coli strain RM5034. Thus, the use of DNA microarrays in combination with photopolymerization allowed the rapid and cost-effective identification of E. coli O157, compared to fluorescence methods that are more expensive and require several days for strain detection.