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Full-Text Articles in Life Sciences
Surface Moisture And Osmotic Stress As Factors That Affect The Sanitizing Of Beef Tissue Surfaces, James S. Dickson
Surface Moisture And Osmotic Stress As Factors That Affect The Sanitizing Of Beef Tissue Surfaces, James S. Dickson
James S. Dickson
The use of osmotic stress or desiccation in combination with 2% acetic acid reduced the numbers of Salmonella typhimurium or Listeria monocytogenes on beef tissue to a greater degree than the acid alone. Bacteria were osmotically stressed by NaCl, CaCl2, or sucrose solutions. Pre-washing with 20% NaCl followed by sanitizing with acetic acid reduced the numbers of S. typhimurium an additional 1.5-to 2-log cycles compared with acetic acid alone. Similar reductions were seen by allowing the tissue surfaces to dry before the application of the acid. Desiccation in combination with acetic acid was also effective in reducing the numbers of …
Use Of A Bacteriocin Produced By Pediococcus Acidilactici To Inhibit Listeria Monocytogenes Associated With Fresh Meat, J. W. Nielsen, James S. Dickson, J. D. Crouse
Use Of A Bacteriocin Produced By Pediococcus Acidilactici To Inhibit Listeria Monocytogenes Associated With Fresh Meat, J. W. Nielsen, James S. Dickson, J. D. Crouse
James S. Dickson
A bacteriocin produced by Pediococcus acidilactici had an inhibitory and bactericidal effect on Listeria monocytogenes associated with fresh meat. MICs were significantly lower than minimum killing concentrations. When meat was inoculated with L. monocytogenes, the bacteriocin reduced the number of attached bacteria in 2 min by 0.5 to 2.2 log cycles depending upon bacteriocin concentration. Meat treated initially with the bacteriocin resulted in attachment of 1.0 to 2.5 log cycles fewer bacteria than that attained with the control. The bacteriocin, after 28 days of refrigerated storage on meat surfaces, was stable and exhibited an inhibitory effect on L. monocytogenes.
Evaluation Of Chicken Heterophil Adherence, Claire B. Andreasen, Kenneth S. Latimer, W. L. Steffens
Evaluation Of Chicken Heterophil Adherence, Claire B. Andreasen, Kenneth S. Latimer, W. L. Steffens
Claire B. Andreasen
Adherence of chicken heterophils was evaluated at 37 C using preconstructed columns containing various weights of nylon fiber (75 mg, 100 mg, or 125 mg) and whole blood anticoagulated with sodium heparin or 10% disodium ethylenediamine tetraacetic acid (EDTA). Additionally, 50-mg and 75-mg nylon fiber columns incubated at 41 C were used to evaluate heterophil adherence at an increased temperature. The mean percent adherence for heparin-anticoagulated blood applied to 75-mg, 100-mg, and 125-mg nylon fiber columns at 37 C was 76%, 92% and 97.4%, respectively. Samples applied to 50-mg and 75-mg columns at 41 C had adherence values of 27% …
Organ Hypertrophy And Responses Of Colon Microbial Populations Of Growing Swine To High Dietary Protein, James S. Dickson, Wilson G. Pond, Vincent H. Varel, Friday O. I. Anugwa, Gary S. Ross
Organ Hypertrophy And Responses Of Colon Microbial Populations Of Growing Swine To High Dietary Protein, James S. Dickson, Wilson G. Pond, Vincent H. Varel, Friday O. I. Anugwa, Gary S. Ross
James S. Dickson
Thirty-two castrated male crossbred growing pigs (average initial wt 26.9 kg) were used to determine the effect of a high level of dietary protein (37%) compared with a normal level of protein (15%) on enterobacteria and Campylobactersp. inhabitation in the large intestine and on visceral organ hypertrophy and the interrelationships between these two factors. Pigs were kept in pairs (eight pens of two pigs/diet) and fed their respective diets ad libitum. Eight pigs (two pens of two pigs fed each diet) were killed at wk 4, 8. 12 and 16 without fasting. Fecal samples were obtained every 2 wk from …
Transfer Of Listeria Monocytogenes And Salmonella Typhimurium Between Beef Tissue Surfaces, James S. Dickson
Transfer Of Listeria Monocytogenes And Salmonella Typhimurium Between Beef Tissue Surfaces, James S. Dickson
James S. Dickson
Beef tissue surfaces were inoculated with either Listeria monocytogenes or Salmonella typhimurium and placed in contact with uninoculated tissue surfaces. The transfer of bacteria from one surface to another was determined under conditions designed to simulate contamination during meat processing. Bacterial transfer decreased when the initial inoculum was allowed to adsorb to the base tissue prior to contact with the second tissue. The type of base tissue was a factor (P<0.05), with a greater transfer from fat with contact times of less than 1 min and a greater transfer from lean with longer contact times.
Comparison Of Homogenization By Blending Or Stomaching On The Recovery Of Listeria Monocytogenes From Beef Tissues, James S. Dickson
Comparison Of Homogenization By Blending Or Stomaching On The Recovery Of Listeria Monocytogenes From Beef Tissues, James S. Dickson
James S. Dickson
Homogenization by blending or stomaching was compared for the recovery of Listeria monocytogenes from inoculated intact beef tissue. There were no differences in numbers of recovered bacteria (P > 0.10) attributable to either homogenization time or method. Fewer viable bacteria (PcO.05) were recovered in phosphate buffer than either buffered peptone water or 2% trisodium citrate buffer. Tween 80 increased the numbers of bacteria recovered from fat tissue (PcO.05). Stomaching is an acceptable method for homogenizing samples for Listeria analysis.
Modeling Environmental Response To Power Interruptions In Swine Nurseries, Jay D. Harmon, E. R. Collins Jr., E. T. Kornegay
Modeling Environmental Response To Power Interruptions In Swine Nurseries, Jay D. Harmon, E. R. Collins Jr., E. T. Kornegay
Jay D. Harmon
A deterministic simulation model was developed to help assess emergency environmental needs of swine nurseries by modeling short term power interruptions. The model accounts for heat exchange by conduction, convection, radiation and air infiltration. A sub-model, developed by the North Central Region Committee 179, was used to predict swine heat and moisture loss. The model was validated using a nursery constructed of concrete block. The model performed well for cases with a constant solar load but tended to overpredict temperature changes during periods of no solar load. Validation indicated that wind velocity had the most effect upon model error. Sensitivity …