Prevalence and control of Listeria, Salmonella and Escherichia coli O157:H7 in Colorado rural households

Consumer's food handling habits at home are important for food safety, and need to be investigated to better prevent illnesses. The objective of this work was to identify risk factors associated with prevalence of Listeria, Salmonella and Escherichia coli O157:H7 in the rural household, and to provide scientific data for the development of reheating instructions for frankfurters.;Households with/without ruminants were recruited. Food and environmental samples, and behavioral data were collected. Listeria was isolated from refrigerators, kitchen sinks, shoes, washing machine and food, with higher prevalence in ruminant households. No sample was positive for E. coli O157:H7. Salmonella was isolated from refrigerators, washing machines, gloves, and shoes. Behavior related to handling of perishable foods affected Listeria prevalence, regardless of ruminant presence. Personal cleanliness habits were related to presence of Listeria on shoes, washing machine, and working gloves.;Two studies evaluated reheating of frankfurters formulated with/without potassium lactate (PL) and sodium diacetate (SD), inoculated with L. monocytogenes, vacuum-packaged, and stored under conditions simulating manufacturing/retail and consumer storage. In one study, frankfurters were placed in a bowl with water and treated in a microwave oven. Exposure to high power for 75 s reduced pathogen levels (0.7+/-0.0 to 1.0+/-0.1 log CFU/cm2) to below the detection limit on frankfurters with PL/SD. On frankfurters without PL/SD, initial levels of L. monocytogenes (1.5+/-0.1 to 7.2+/-0.5 log CFU/cm2) on untreated samples increased during storage, and exposure to high power for 75 s produced reductions between >1.5 and 5.9 log CFU/cm2. Depending on the treatment and storage time, the heating water had viable L. monocytogenes counts. Levels of L. monocytogenes contamination <3.7 log CFU/cm2, on frankfurters can be significantly reduced by microwave oven heating at high power for at least 75 s.;In the other study, inoculated frankfurters were treated with hot water. Treatments at 80°C and 94° reduced pathogen counts on frankfurters with PL/SD to at/below the detection limit. For frankfurters without PL/SD, pathogen numbers reached up to 6.1 log CFU/cm2 and hot water treatments reduced counts by 1.0 to >6.0 log CFU/cm2. No survivors were detected in the heated water after any treatment.