A-68
DNA microarray for food safety analysis.
N. Sergeev1,2, M. Distler3, S. Courtney3, S. F. Al-khaldi2, D. Volokhov4, V. Chizhikov4, A. Rasooly1,2,5, 1FDA Center for Devices and Radiological Health, 2FDA Center for Food Safety and Applied Nutrition, 3JIFSAN-University of Maryland, 4FDA Center for Biologics Evaluation and Research, 5NIH-National Cancer Institute.
The large and diverse number of food microbial pathogens and their virulence factors has fueled interest in technologies capable of detecting multiple pathogens and multiple virulence factors simultaneously. The primary aim of this project was to develop a multipathogen oligonucleotide microarray (FDA-1) for simultaneous analysis of S. aureus enterotoxin genes, Listeria spp., Campylobacter spp. and Clostridium perfringens toxin genes using a single chip. Our two-step method require an initial PCR amplification step, followed by identification of the fluorescently labeled amplicons by hybridization to a DNA microarray. DNA microarrays are small, solid supports onto which large numbers of gene-specific DNA sequences are attached in an orderly arrangement at high density.
For FDA regulatory use, three elements were incorporated to increase confidence in this system: multiple genes for microbial identification, multiple oligonucleotide probes (oligoprobes) for each specific gene, and quality control oligoprobes to monitor array spotting and DNA hybridization. The combination of these elements enhances the reliability of detection and reduces the chance of erroneous results due to the genetic variability of microbes or technical problems with the microarray.
The method described here was used successfully for identification of S. aureus enterotoxin genes, Listeria spp., Campylobacter spp. and Clostridium perfringens. The results presented demonstrate the potential of oligonucleotide microarrays for detection of microbial pathogens relevant to food safety and biodefense.
2004 FDA Science Forum | FDA Chapter, Sigma Xi | CFSAN | FDA
Last updated on 2004-APR-30 by frf