Testing for pathogens in products and plants is part of food safety, but not all of it. “The tests we provide are a look at what pathogens may be there,” said Mike Clark, a microbiologist and global marketing manager in molecular food diagnostics for Bio-Rad Laboratories. “But these tests are certainly not preventive.” The reason is, these tests do not prevent pathogens and bacteria from getting into plants and into the food products being produced there, or into the food chain, he said. “That’s why testing programs in plants can never replace what we call ‘good manufacturing practices (G.M.P.s).’ These G.M.P.s are part of a good strong HACCP program or system, which of course has been required many years in poultry and meat plants by U.S.D.A. regulations,” Mr. Clark said. “The G.M.P.s include HACCP, sanitation, a complete food safety program. When you have that operating in a plant, then the risk of bacteria and pathogens, and possibly foodborne illness in consumers who purchase the food products, is reduced.” But product testing is needed in plants and plays a critical role in eliminating food safety threats.

To identify problems in plants, Bio-Rad supplies its meat and poultry facility customers with real-time polymerase chain reaction (RTi-PCR or RT-PCR) or qPCR tests. This technology can be used to find pathogens like Listeria monocytogenes, Salmonella, Campylobacter, E. coli O157:H7 and non-O157 Shiga toxin-producing E. coli (STEC) pathogens in plants or products. “PCR can detect foodborne pathogens by generating many thousands, even millions of copies of DNA of the targeted pathogen,” Mr. Clark said. “This is a very sensitive and accurate test. The accuracy of our test is improved due to the continuous detection throughout the PCR test, not just at the end. By using this method, we’re continuously monitoring the test results, so we have the results even faster, including presumptive results faster.” Bio-Rad’s test line is called iQ-Check Real-Time PCR. Bio-Rad recently released an even more advanced testing solution based on Droplet Digital PCR (ddPCR). This process generates thousands of extremely small droplets, dividing a single sample into 20,000 individual reactions. This new solution from Bio-Rad is called dd-Check STEC, which is used to detect Shiga toxin-producing E. coli (STEC). “It changes the way and speed STEC is found,” Mr. Clark said. “For a STEC bacterium to be considered a pathogen, two virulence markers in a single bacterium need to be present. Droplet digital PCR can detect and confirm both virulence genes occurring in a single cell. It gives users a better and more accurate result.” Advantages include reducing the number of false positives. For fresh meat, confirmed positive and negative results can be back in as little as 24 hours. Other methods don’t paint as accurate a picture, Mr. Clark said, with presumptives confirmed or not confirmed as quickly. Slower methods also require meat and poultry products to be held longer.