University calls on Army for chemical testing of meat product
March 14, 2013
ABERDEEN PROVING GROUND, Md. (March 14, 2013) -- When a South Dakota beef producer voiced concerns over the safety of its product to a meat inspection staff, the Animal Disease Research and Diagnostic Laboratory at South Dakota State University, called on the Food Emergency Response Network for help in early January. Within a few days, the U.S. Army Research, Development and Engineering Command's chemical-biological center, or ECBC, answered.
"It was really great," said Laura Ruesch, research associate II at SDSU. "I would have had no way of knowing that [Edgewood Chemical Biological Center] existed if it weren't for the [Food Emergency Response Network]. It was a really great way to connect people who have the resources and similar interest in food testing, but otherwise would not have had contact with one another."
Food Emergency Response Network, known as FERN, an integrated system of food-testing laboratories across local, state and federal levels in the United States, facilitated the partnership between SDSU and ECBC's CBARR Business Unit laboratories at the Aberdeen Proving Ground, Md. Federal and state funding cuts caused SDSU's biochemistry laboratory to close in 2011, leaving the university without the facility or personnel to support a core chemistry capability for food testing. Furthermore, the absence of a Department of Agriculture laboratory in South Dakota left Ruesch with little state resources to reach out to. Instead, she utilized her contacts within FERN to connect to CBARR's Environmental Chemical Monitoring Laboratory.
As part of South Dakota's meat inspection program, SDSU needed to conduct additional chemical testing on a meat sample to determine whether or not Ivermectin, an anti-parasitic agent, was present. According to Ruesch, the Ivermectin compound is used in a pesticide that is poured on live cattle to control internal and external parasites such as roundworms, cattle grubs, mites, lice and flies.
"Typically, there is a withdrawal period of 45 days before they can slaughter that animal," Ruesch said. "Whatever product was absorbed into the body of the cow was processed by the liver and kidneys and excreted via feces and urine so levels present in the tissue are reduced to tolerable levels."
The meat sample in question, however, had been processed before the 45-day time period, after only 28 days. Additional testing was conducted by CBARR to ensure the meat sample was not contaminated and the Ivermectin compound was not still present. The anti-parasitic agent is widely used as insecticides in agriculture, gardens and veterinary practices. When exposed to unsafe levels of the chemical, humans may develop mydriasis, depression, coma, tremors, ataxia, stupor, vomiting and drooling. After two weeks of testing, CBARR did not find any hazardous levels of Ivermectin in the meat samples.
"A lot of chemistry laboratories that have such a high sample throughput usually don't have the time for some of these more unique cases," Ruesch said. "ECBC really went out of their way to help us out. A lot of places just didn't have the time or the qualified staff available to investigate that method and put it into place."
Nam-Phuong Nguyen, CBARR senior chemist, was excited to take on the task. Based on previously proven USDA methods and the work conducted with raw milk samples, Nguyen developed and verified the appropriate method for detecting the presence of Ivermectin in the ground beef product sample provided by SDSU.
"After we received the samples, I applied my research to develop the analytical methods," Nguyen said. "Using the reference standard provided by Ruesch, I started working on the acquisition methods by first running in scan mode to find and optimize the signal intensity at the peak of interest."
Nguyen had previous experience creating and verifying testing methods, an invaluable resource when conducting this type of work with a quick turnaround time. According to Nguyen, other projects tend to take longer to complete because they typically involve validating another scientist's methods. But because Nguyen had designed the test methods for the FERN project herself, there was only one matrix and one analysis that needed to be done. Method validation serves to ensure that a specific process provides the results researchers anticipate.
"Before working on this project for SDSU, CBARR had done work on a food project for the USDA where we were asked to validate their developing method of detecting three compounds of interest in various food matrices, including orange juice, apple juice, egg yolk, egg white, whole milk, two percent milk, hot dog and ground beef, and deli turkey," Nguyen said. "Although the two projects were seemingly different, the same concepts, with respect to the development and validation of methods, were applied."
Out of nearly 10 laboratories across the country who responded to SDSU's FERN request for chemical testing capabilities, CBARR was the only one awarded the work. CBARR was accepted into FERN as a chemical, biological and radiological testing laboratory in January 2009, and has performed method equivalency testing for biological analysis with food matrices for other FERN partners. The work with SDSU marks the first time CBARR has expanded its FERN efforts to include chemical testing.
ADRDL is integrated into SDSU's Department of Veterinary and Biomedical Sciences, and joined FERN in 2004. ADRDL is one of fewer than 40 veterinary diagnostic laboratories accredited by the American Association of Veterinary Laboratory Diagnosticians. It is also an integral member of the National Animal Health Laboratory Network that helps detect nationally significant animal diseases like avian influenza.
ECBC is part of the U.S. Army Research, Development and Engineering Command, and the partnership with SDSU highlights each organization's commitment to detect agents of food-borne illness, and respond to emergencies involving the contamination of food. The inter-agency participation within the FERN structure enhances the network's ability to form, develop and operate across the country on complex issues involving the nation's food supply.