Challenging the Food Emergency Response Network with the Detection of a Select Agent in Foods

Introduction: Abrin is an extremely toxic ribosomal inactivating protein commonly found in the tropical plant, Abrus precatorius. Abrin toxicity inhibits the synthesis of cell proteins, causing severe illness and cell death. Although the use of abrin has not been documented in a bioterrorism event, its lethality, availability, ease of dissemination, and lack of antidote make it a dangerous foodborne contaminate with the potential for bioterrorism activity. Food proficiency testing programs for many select agents, including abrin, are not readily available. Food defense laboratories within the network are required to prove competency prior to providing testing capabilities for surveillance and surge testing of abrin toxin in foods.

Purpose: The objective of this activity was to provide a challenging proficiency test to the Food Emergency Response Network for the detection of abrin toxin in foods.

Methods: Temperature and stability studies were conducted with abrin toxin in hot dogs for three weeks, prior to shipping of samples. Twelve participating laboratories throughout the country received eight unknown samples, fortified with abrin toxin (varying from 500 to 1,000 ng/g), as well as blanks. Laboratories analyzed samples following the FERN.MIC.0021 method, incorporating a toxin extraction via centrifugation in conjunction with the Tetracore Abrin ELISA detection kits.

Results: All laboratories (12 of 12) reported the qualitative sample results with 100% proficiency (96 of 96). Eleven of twelve (11 of 12) participating laboratories, additionally, reported quantitative absorbance values for each sample analyzed. All z score calculations for individual laboratory results were acceptable |z|<3, based on the total comparison group’s mean consensus calculated absorbance and standard estimation of variation.

Significance: The data generated from this activity was utilized by state laboratories across the country to provide evidence of individual competency for the detection of abrin in foods. This method was used in 2016 for a national biodefense surveillance activity for abrin detection.