NEW YORK (GenomeWeb) – A collaboration between Toshiba and Kawasaki City Institute for Public Health in Kanagawa, Japan has resulted in the development of a DNA chip card that detects 14 food-borne pathogens from fecal samples in about 90 minutes.
The assay is based on Toshiba's patented technology and will also have applications for hygiene management in food manufacturing, pharmaceuticals, and cosmetics, the firm said in a statement.
Currently Toshiba is targeting public health applications in Japan, Keiichi Yamamoto, a researcher at Toshiba and one of the chip's developers, told GenomeWeb in an email.
The DNA chip card and detection device, called Genelyzer, were previously developed by Toshiba. Kawasaki City Institute for Public Health provided the technical information about public health for developing the food-borne pathogens DNA chip card and chose the bacterial targets, Yamamoto explained.
The assay uses a fecal sample from a person who is suspected to have food poisoning. Sample prep is carried out off-chip and by manual alkali extraction, Yamamoto said.
The research-use only card relies on loop-mediated isothermal amplification (LAMP). Amplified products hybridize with immobilized DNA spots within the card, and hybridization is signaled by anodic current derived from an electrochemically active intercalator substance.
The chip can detect Salmonella, Campylobacter, Vibrio parahaemolyticus, Shigella, Staphylococcus aureus, Clostridium perfringens, Bacillus cereus, Yersinia, Listeria, Vibrio cholerae, as well as enteropathogenic, enterotoxigenic, enterohemorrhagic, and enteroaggregative Escherichia coli.
A similar product from Mobidiag that uses qPCR was recently CE-marked, as reported by GenomeWeb. A number of other firms also manufacture GI panels that detect bacterial targets in stool samples, including Nanosphere, Becton Dickinson, BioFire Diagnostics, and Luminex, but these are being marketed for clinical diagnostic use. Â
The core technology of Toshiba's DNA chip card was described a few years ago in the Journal of Biosensors & Bioelectronics, Yamamoto said.
In that publication, the combination LAMP-based amplification and electrochemical DNA detection was called Bio Bulwark.
"Anodic current derived from Hoechst 33258, an electrochemically active intercalator, was relative to the amount of the target DNA hybridized with target-specific probes on the DNA chip," the study explained. In this proof-of-principle work, detection of Bacillus anthracis was carried out within 70 minutes.
Yamamoto refrained from commenting on Toshiba's pipeline of product development for the DNA chip card, except to note, "We have started to sell a DNA chip card for cultivar discrimination of rice in Japan."
The DNA chip card technology is patented, Yamamoto said, but declined to provide additional details about licensing.