NEWS SCAN: Salmonella from Taco Bell, E coli from ground beef, classification of select agents

Aug 6, 2010

Taco Bell cited as source of Salmonella outbreak
The Centers for Disease Control and Prevention (CDC) and health officials in Washington and Oregon have said that food served at Taco Bell restaurants is behind at least some of the recent cases of Salmonella Hartford and Salmonella Baildon, according to reports from Food Safety News and the Oregonian newspaper. However, no particular food item or supplier has been pinpointed as yet. The Food and Drug Administration has undertaken an extensive traceback effort to identify exactly where the bacteria are coming from but has so far been unsuccessful, the reports said. At least 155 people in 21 states became ill with salmonellosis between the beginning of April and late July. William Keene, senior epidemiologist with Oregon Public Health, told the Oregonian that Taco Bell is clearly the source for many of the illnesses but not all of them. Although no single food source has been identified, epidemiologists think lettuce or tomatoes or both are to blame, Keene said. He also said the food source was contaminated before reaching Taco Bell franchises. Laura Gieraltkowski, a CDC epidemiologist, said about a third of the Salmonella Harford and 40% of the Baildon patients were hospitalized, the Oregonian reported.
Aug 6 Food Safety News article
Aug 5 Oregonian article

California firm recalls ground beef in wake of E coli cases
Valley Meat Co. of Modesto, Calif., is recalling about 1 million pounds of ground beef in connection with a cluster of seven Escherichia coli O157:H7 infections involving a rare strain, the US Department of Agriculture announced today. The products subject to recall bear the establishment number "EST. 8268" on the USDA mark of inspection; they were produced between Oct 2, 2009, and Jan 12, 2010, and were distributed to retails stores and food services in California, Texas, Oregon, Arizona, and foreign countries. The USDA and the producer are concerned that some products may still be in customers' freezers, officials said. California health officials identified six E coli cases with onset dates between Apr 8 and Jun 18 and later found a case that occurred in February, the USDA said.
Aug 6 USDA press release

NRC ponders classifying select agents by DNA sequences
In a report issued this week, a committee of the US National Research Council (NRC) said it will not be possible anytime soon to predict a microorganism's properties, such as pathogenicity or transmissibility, from its DNA sequences. However, the panel said it is technologically feasible to classify "select agents"—dangerous bacteria, viruses, toxins, and fungi—on the basis of their gene sequences, and such a classification could provide "much needed clarification" for administering the federal select agent regulations. Further, it would be possible to develop a "yellow flag" biosafety system for dealing with sequences deemed to be of concern, the report said. The system would involve a centralized sequence database that would be annotated as evidence of the function of suspect sequences is acquired. A "yellow flag" sequence would not necessarily be regulated, but companies that make synthetic DNA could use the information to screen orders for such sequences, noted a Nature news story about the report. While finding sequence-based classification and a yellow-flag system feasible, the NRC committee did not actually recommend developing them, saying it did not examine their cost or their potential impact on basic research or national security. The group said its principal finding was that sequence-based prediction of select agent properties is not feasible and that any research dedicated solely to this purpose is likely to have only negative consequences.
NRC page with access to report
Aug 3 Nature article

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