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about me
Name Katherine Kirby Neubert Birthday 09.13.87 Email katherineneubert@hotmail.com -- writer, jolter, aspiring photojournalist.
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alexis design the daily collegian the daily jolt the new york times wordswift |
Tuesday, May 27, 2008
A bacterium known as Listeria monocytogenes is known to surface commonly purchased foods and may be very harmful to a consumer's health.According to David Nyachuba, a food safety specialist at the University of Massachusetts, Listeria is bacteria found in everything and everywhere: the soil, the ground, all surfaces, animals and food. The way the bacteria can get into these ready-to-eat foods is from most of the surfaces they are placed on. If any surface is not properly tested prior to food being processed on it, Listeria can easily contaminate any food that has been placed on that surface. "Foods with Listeria don't look or taste bad, but still could be contaminated," said Nyachuba, adding that most ready-to-eat foods that have potential to be contaminated vary from salads to deli meats, smoked salmon and pasteurized or raw milk and cheeses. Eating foods with Listeria in them isn't a problem as long as the consumer is healthy. People who may have HIV, problems with constipation, a low immune system, are pregnant or are elderly, among many other conditions, have a greater risk of becoming ill. The only way for any person to avoid eating foods with Listeria in them is to start from the root of the operation: detecting it in foods before they hit the market. This starts where the food is processed. "Food processing treatments like heating, freezing, exposure to sanitizing compounds, acidification [and] addition of additives like sodium nitrite can result in sub-lethal 'injury' of this pathogen," said Nyachuba. One way of controlling and preventing Listeria from contaminating food is to do mandatory environmental testing on surfaces that will come into contact with food all the time. Nyachuba and his colleagues have modified existing techniques for helping detect Listeria and developed a more selective method, which he hopes the United States Department of Agriculture and Food and Drug Administration will pick up. "The current USDA and FDA methods for detecting and recovering use highly selective enrichment media," said Nyachuba. "Thus, these methods may fail to detect 'injured' Listeria that could essentially recover and start growing again, in places like your refrigerator over prolonged storage, growing easily at 41 degrees Celsius." Instead of having just one enrichment method, Nyachuba has demonstrated that the recovery of Listeria from food could be significantly improved through use of repair-enrichment protocols with dual primary enrichment, which facilitates Listeria detection and recovery. "Instead of using one enrichment medium, the modified method uses two," he said. "We also have developed a primary enrichment medium, which is one of the two that the modified method uses. This new dual-enrichment method helps better detect 'injured' Listeria in food and environmental samples than when just one primary enrichment medium is used." Nyachuba also feels the need to expand sanitizers on environmental surfaces, paying close attention to the floor, the walls, stainless steel surfaces, brick and more. Listeria can be brought in from the outside on anything, even after a surface has been tested. Being able to detect and eliminate harborage sites of Listeria is key to controlling this organism. To do that, methods that are capable of detecting injured as well as uninjured Listeria are critical. Sub-lethal injuries can grow on any surfaces, so it is important for any environment with food processing to consistently be free of Listeria. Nyachuba is the newest assistant professor in the department of nutrition at UMass, as well as Extension's Food Safety Education Program director. He has been studying the effects of Listeria monocytogenes among other bacteria in foods for a number of years, starting in his final undergraduate year at the University of Nairobi, Kenya. He is determined to get his new methods for testing and finding these "injured" microbes in ready-to-eat foods out in the open. Still working with an advisor from the University of Vermont, he is trying to set up a lab and get funding to do some of his research at UMass. On top of that, he does extension work teaching food safety for family daycare providers, in an effort to reduce food illnesses, as children fit into the category of people who are very susceptible to illness from bad food pathogens. --- *You can view this article here. "Kat" [
5:37 PM ] |