Submitted to: International Journal of Food Microbiology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/10/2009
Publication Date: 4/1/2009
Citation: Dourou, D., Porto Fett, A.C., Shoyer, B.A., Call, J.E., Nychas, G.E., Illg, E.K., Luchansky, J.B. 2009. BEHAVIOR OF ESCHERICHIA COLI O157:H7, LISTERIA MONOCYTOGENES, AND SALMONELLA TYPHIMURIUM IN TEEWURST, A RAW SPREADABLE SAUSAGE. International Journal of Food Microbiology. 130 245-250. Interpretive Summary: Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella Typhimurium are bacterial pathogens that have been associated with outbreaks of illness in a variety of meat products. Teewurst is a traditional sausage of Germanic origin that is made with raw pork and beef and is characterized by a soft and spreadable texture. Recently, consumption of teewurst has caused illness due to the presence of Escherichia coli O157:H7 and Listeria monocytogenes in the product. Thus, this study was conducted to examine the behavior of these three pathogens placed either into teewurst batter or onto the surface of the finished product that were then stored at refrigeration and abuse temperatures. The results showed that when the pathogens were placed into the batter, in general, the higher the storage temperature, the greater the reduction in pathogen levels. When placed onto the surface of sliced finished product, the results also showed a significant decrease for E. coli O157:H7, S. Typhimurium, and L. monocytogenes, respectively, over the course of about a month. Our data establish that teewurst does not support growth of these pathogens.
Technical Abstract: The fate of Listeria monocytogenes, Salmonella Typhimurium, or Escherichia coli O157:H7 were separately monitored both in and on teewurst, a traditional raw and spreadable sausage of Germanic origin. Multi-strain cocktails of each pathogen (ca. 5.0 log CFU/g) were used to separately inoculate teewurst that was stored at 1.5 degree, 4 degree, 10 degree, and 21 degree C. When inoculated into commercially-prepared batter just prior to stuffing, in general, the higher the storage temperature, the greater the reduction in pathogen levels. Depending on the storage temperature, pathogen levels in the batter decreased by 2.3 to 3.4, ca. 3.8, and 2.2 to 3.6 log CFU/g for E. coli O157:H7, S. Typhimurium, and L. monocytogenes, respectively, during storage for 30 days. When inoculated onto both the top and bottom faces of sliced commercially-prepared finished product, the results for all four temperatures showed a decrease of 0.9 to 1.4, 1.4 to 1.8, and 2.2 to 3.0 log CFU/g for E. coli O157:H7, S. Typhimurium, and L. monocytogenes, respectively, over the course of 21 days. With the possible exceptions for salt and carbohydrate levels, chemical analyses of teewurst purchased from five commercial manufacturers revealed only subtle differences in proximate composition for this product type. Our data establish that teewurst does not provide a favourable environment for the survival of E. coli O157:H7, S. Typhimurium, or L. monocytogenes inoculated either into or onto the product.