IN an article published in Frontiers in Microbiology on Dec. 20, U.S. Department of Agriculture researcher Pina Fratamico describes using a next-generation real-time polymerase chain reaction (PCR) system to discover specific gene targets that indicate the presence of dangerous foodborne pathogens such as Escherichia coli.
The results show that assays performed using this PCR system are rapid, sensitive and reliable.
"Testing using these types of systems is faster, easier and more reproducible than previous methods, and this should increase food safety in the long run. I feel that we could confidently move to these new systems for screening ground beef and other foods for E. coli contamination," said Fratamico, who is with USDA's Agricultural Research Service in Wyndmoor, Pa.
Not all E. coli are dangerous, but certain strains produce a potentially dangerous toxin called Shiga toxin. These Shiga toxin-producing E. coli (STEC) can be found in raw meat and can cause serious food poisoning in people.
"Certain groups of STEC have been declared as adulterants by the USDA Food Safety & Inspection Service, and the availability of rapid and reliable tests for these pathogens is critical so that testing results are available before meat is shipped to restaurants and consumers," Fratamico said.
The meat industry has used the PCR protocol for some time. The genetic test detects the presence of specific gene targets that indicate the existence of STEC in meat.
The new generation of real-time PCR systems, like GeneDisc from Pall Technologies in France used in this particular study, employ a self-contained unit that standardizes the procedure and tend to be relatively portable and easy to use -- offering obvious advantages for both meat processors and inspectors from the industry and government alike.