RAPID TESTS FOR FOOD INFECTION-WILL THEY EVER REPLACE CULTURE TESTS?

Food-borne infection episodes are becoming more and more conspicuous by their recurring occurrence in countries like the US and fast detection and identification of the contaminant is a high priority area of interest to the industry. Conventional culture tests take at least 24 hours though in many cases it may stretch to 3-5 days. As the volume of production is increasing day by day due to growing demand for processed foods, it is next to impossible for the industry to organize culture based diagnosis and this is pushing the scientific community to evolve quick tests as a part of the safety protocol for helping the industry. There are a few quick tests available now which can give results under an hour and these are being increasingly deployed in the industry. But there is no unanimity whether such quick tests can be solely depended upon and the conventional culture tests can be dispensed with totally. Here is a critique on this vital issue which needs to be resoled quickly for a universal regime acceptable o all the stake holders.  

"Tests for food-borne pathogens in which a culture is not grown in a lab may be necessary for produce companies, but they can't replace traditional culture tests, industry leaders and government officials say. Non-culture diagnostic tests have been around since the early 1980s, said David Gombas, senior vice president of food safety and technology for the Washington D.C.-based United Fresh Produce Association. But there has been a recent push, Gombas said, to use them to replace culture tests that the Centers for Disease Control and Prevention, the Food and Drug Administration and other agencies and organizations rely on to accurately diagnose cases of salmonella, E. coli and other food-borne illnesses. That trend was highlighted in a recent article in Scientific America magazine, which found that many clinics and state-run labs are turning to nonculture tests, which are faster than culture tests. They're faster, but are they better? "Right now, the answer is no," Gombas said. "CDC, FDA, and those in the produce industry I talk to — they want a live bug." A live bug is the result of growing a culture, which can take 18 to 24 hours in a lab, Gombas said. Some of the rapid non culture tests, by contrast, can be done in 20 minutes. For many fresh produce companies, like Earthbound Farm, San Juan Batista, Calif., rapid non culture tests are a necessity, said Will Daniels, Earthbound's senior vice president of operations and organic integrity. "Without them, we wouldn't be able to do what we do," Daniels said. "A culture is a three to five day process. We can't fit that into our system." Earthbound Farms tests every product it ships. If it relied on culture tests and had to wait three to five days to ship, it would need to have five to six days' worth of inventory on hand at any given time, Daniels said."

There is point in the argument of the industry that it cannot hold on to huge stocks of foods in their warehouses, waiting for the results of culture tests to arrive before releasing into the market and naturally inventory management can be a nightmare, especially for large manufacturers, affecting their economical viability. At the same time consumer safety is sacrosanct and cannot be compromised at any cost. Probably safety scientists may have to evolve some sort of empirical correlation between quick testing regime and frequency of culture testing to make sure that the system s absolutely reliable. It must be admitted that quick tests are possible only for known pathogens and as and when new bugs arrive, culture tests are inevitable to identify them. Considering the enormity of the problem, food industry should not rely entirely on modern quick tests and do way with conventional diagnostic tools!

V.H.POTTY
http://vhpotty.blogspot.com/
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