Georgia Tech and the University of Georgia to Collaborate on Unique Bioterror Screening Tool

In a recent request for proposals, the U.S. Food and Drug Administration (FDA) announced the availability of funds to support collaborative research efforts aimed at reducing the incidence of foodborne illness and ensuring the integrity of the nation’s food supply. One category of research included the development of rapid analytical screening methods for the detection of pathogens that are not usually associated with food and foodborne illness at low levels and without traditional enrichment methods. The same technologies being developed to assist food processors with the monitoring and reduction of the more common foodborne pathogens (Salmonella, Campylobacter, Listeria, E. coli O157:H7) can be adapted and applied to the insidious bioterror weapons (Anthrax, Plague, Smallpox).

To address this need, a joint proposal to further develop Georgia Tech’s interferometric biosensor (see page 3) and apply it to the detection of a bioterror agent in food was prepared and submitted by the Georgia Tech Research Institute (Principal Investigator: David Gottfried) and the Center for Food Safety at the University of Georgia (Principal Investigator: Michael Doyle). This project was recently funded for a three-year period ($600,000) and will begin shortly.

Although the concept of using biosensor technology as an adjunct to current food processing industry practice has existed for some time, no truly rapid (real-time) analysis methods (those not requiring sample enrichment steps) are commercially available for pathogen detection in food matrices. Detection of pathogens is still a process that usually requires 24-48 hours, although some recent tests have demonstrated detection in 8-9 hours. Even though the actual assay component may be “rapid” (conventionally defined as less than 4 hours within the food industry), samples still need to be enriched with conventional culture methods to increase low bacteria counts to detectable levels.

Aside from more traditional laboratory-based polymerase chain reaction and immunoassay techniques, new developments in biosensor technology have been applied to food pathogen and bioweapons detection and quantification. In some of these biosensors, an antigenic fraction, rather than the whole cell, is detected and the immunoassay uses a conventional sandwich format with antibody labeling and several rinse steps. More recently, a group of researchers at the Massachusetts Institute of Technology demonstrated rapid and sensitive detection of pathogens using genetically engineered B-cells with surface-expressed antibodies and a luminescent response gene. However, many of these approaches have yet to be taken out of the laboratory and applied in field-usable versions.

The objective of the funded FDA project is to develop a rapid (less than 3 hours), specific (no cross-reaction), sensitive (100 to 1,000 cells/ml without enrichment procedures required), and easy-to-use (no special training) approach for early detection of a bioterror bacterial pathogen in food and environmental samples. Initially, the project will focus on the production of new monoclonal antibodies specific for the agent. Then these antibodies will be coupled with the interferometric waveguide immunoassay biosensor. Work will focus on optimization of the assay parameters for rapid, selective, and sensitive detection in aqueous medium. Different monoclonal antibodies will be used individually and in combination on a multi-assay optical chip. Finally, the developed immunoassay will be applied to the detection of pathogen in contaminated water, juice, and milk samples.