Agreed - this could be very significant.
Here are the two abstracts
Evaluation of an Electrochemiluminescent Immunoassay for the Direct Detection of Food Borne Pathogens in Human Fecal Samples
R. J. Obiso, J. White
IGEN International, Inc., Gaithersburg, MD
Presentation Number: V-12
Keywords: electrochemiluminescence, food borne pathogens, pathogen detection
Detection of most gastrointestinal pathogens in fecal samples is based on the isolation of the pathogen using selective agar plates, followed by biochemical identification and possible serological classification. These procedures may take as long as 4 days. Therefore, a more rapid method is required to determine the presence of these pathogens in feces. Further, ELISA- and PCR-based methods to detect antigen or virulence genes require sample processing, sample washing, or even DNA/RNA purification methods. In this study, the clinical utility of ORIGEN® electrochemiluminescent (ECL) immunoassays were evaluated in human fecal samples. To evaluate the capacity of ORIGEN technology, human fecal samples were collected and tested for the presence of E. coli O157, Salmonella species, and Campylobacter species using IGEN International’s PATHIGENTM detection assays (PATHIGEN E. coli O157 test, Salmonella test, and Campylobacter test), which are currently used to detect food borne pathogens in food and water samples. For pure bacterial cultures, the sensitivities of the PATHIGEN tests are in the range of 100-5000 bacteria, making direct detection from feces possible. Direct detection of specific bacteria in feces was performed for each pathogen tested. The level of sensitivity was comparable to pathogens detected in food and water samples (spiking studies). To assess the assays’ performance clinically, fecal samples from patients were subjected to routine culture techniques and the ORIGEN–based tests. The assay takes approximately 1.5 h without a need for enrichment of the samples. These methods to detect food borne pathogens in feces may be useful for a rapid clinical diagnosis of gastrointestinal infection.
Development and Evaluation of an Electrochemiluminescence-Based Immunoassay for the Detection of E. coli O157 in Food
C. C. Young, Z. Abbas, R. J. Obiso, J. A. White
IGEN International, Inc., Gaithersburg, MD
Presentation Number: P-79
Keywords: E. coli O157, detection, electrochemiluminescence
The increased sensitivity of newly developed culture-based methods that utilize immunomagnetic bead capture for the detection of E. coli O157 has resulted in the identification of positive samples that had previously gone undetected. Current immunoassay formats used to screen foods, such as ELISA and lateral flow device technologies, are less sensitive than these new, culture-based methods. Therefore, the development of more sensitive rapid detection methods is critical to provide a screening test prior to culture confirmation. In this study, an ORIGEN®-based electrochemiluminescent immunoassay (PATHIGENTM E. coli O157 Test) for the detection of E. coli O157 in food matrices was developed and evaluated. The assay could detect as few as 100 E. coli O157 cells in a variety of food matrices allowing detection after enrichment times as short as 6 hours. This sensitivity was 2-4 logs greater than commercially available ELISA and lateral flow device immunoassay formats and was equivalent to the newly available culture methods. A random screen of 500 food samples using the PATHIGEN E. coli O157 Test followed by confirmation using immunomagnetic bead separation and plating onto RainbowTM Agar, was conducted. In this study, 40 additional E. coli O157 positive samples were confirmed that were not detected using a combination of standard screening and plating methods. Based on this data, we conclude that routine use of more sensitive screening methods is vital to protecting the food supply from foods contaminated with E. coli O157.
One discrepancy between the abstract and the PR is the time needed for the assay. Abstract says 1 1/2 hours, whereas the PR says (speaking more generally) as little as 10 minutes. For a doctor's office POC 1 1/2 hours is too long for a "while you wait" test. But still clearly much better than the 1-2 days it presently takes to just culture a sample.
Peter |
