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Life Sciences

University of Nebraska - Lincoln

Department of Food Science and Technology: Faculty Publications

2004

Articles 1 - 8 of 8

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Measurements Of Fitness And Competition In Commensal Escherichia Coli And E. Coli O157:H7 Strains, Lisa M. Durso, David R. Smith, Robert W. Hutkins Nov 2004

Measurements Of Fitness And Competition In Commensal Escherichia Coli And E. Coli O157:H7 Strains, Lisa M. Durso, David R. Smith, Robert W. Hutkins

Department of Food Science and Technology: Faculty Publications

Although the main reservoirs for pathogenic Escherichia coli O157:H7 are cattle and the cattle environment, factors that affect its tenure in the bovine host and its survival outside humans and cattle have not been well studied. It is also not understood what physiological properties, if any, distinguish these pathogens from commensal counterparts that live as normal members of the human and bovine gastrointestinal tracts. To address these questions, individual and competitive fitness experiments, indirect antagonism assays, and antibiotic resistance and carbon utilization analyses were conducted using a strain set consisting of 122 commensal and pathogenic strains. The individual fitness experiments, …


Dna Sequence Analysis Of Regions Surrounding BlaCmy-2 From Multiple Salmonella Plasmid Backbones, W.P. Giles, Andrew K. Benson, M.E. Olson, Robert W. Hutkins, J.M. Whichard, P.L. Winokur, P.D. Fey Aug 2004

Dna Sequence Analysis Of Regions Surrounding BlaCmy-2 From Multiple Salmonella Plasmid Backbones, W.P. Giles, Andrew K. Benson, M.E. Olson, Robert W. Hutkins, J.M. Whichard, P.L. Winokur, P.D. Fey

Department of Food Science and Technology: Faculty Publications

The emergence in the United States of resistance to expanded-spectrum cephalosporin (e.g., ceftriaxone) within the salmonellae has been associated primarily with three large (>100-kb) plasmids (designated types A, B, and C) and one 10.1-kb plasmid (type D) that carry the blaCMY-2 gene. In the present study, the distribution of these four known blaCMY-2-carrying plasmids among 35 ceftriaxone-resistant Salmonella isolates obtained from 1998 to 2001 was examined. Twenty-three of these isolates were Salmonella enterica serotype Newport, 10 were Salmonella enterica serotype Typhimurium, 1 was Salmonella enterica serotype Agona, and 1 was Salmonella enterica serotype Reading. All 23 …


Development Of A Novel Chloramphenicol Resistance Expression Plasmid Used For Genetic Complementation Of A Flig Deletion Mutant In Treponema Denticola, Linda L. Slivienski-Gebhardt, Jacques Izard, William A. Samsonoff, Ronald J. Limberger Jun 2004

Development Of A Novel Chloramphenicol Resistance Expression Plasmid Used For Genetic Complementation Of A Flig Deletion Mutant In Treponema Denticola, Linda L. Slivienski-Gebhardt, Jacques Izard, William A. Samsonoff, Ronald J. Limberger

Department of Food Science and Technology: Faculty Publications

A new expression plasmid containing the fla operon promoter and a staphylococcal chloramphenicol resistance gene, was constructed to help assess the role of fliG in Treponema denticola motility. Deletion of fliG resulted in a nonmotile mutant with a markedly decreased number of flagellar filaments. Wild-type fliG genes from T. denticola and from Treponema pallidum were cloned into this expression plasmid. In both cases, the gene restored the ability of the mutant to gyrate its cell ends and enabled colony spreading in agarose. This shuttle plasmid enables high-level expression of genes in T. denticola and possesses an efficient selectable marker that …


Regulation Of Transcription Of Compatible Solute Transporters By The General Stress Sigma Factor, ΣB, In Listeria Monocytogenes, Mehmet Sevket Cetin, Chaomei Zhang, Robert W. Hutkins, Andrew K. Benson Feb 2004

Regulation Of Transcription Of Compatible Solute Transporters By The General Stress Sigma Factor, ΣB, In Listeria Monocytogenes, Mehmet Sevket Cetin, Chaomei Zhang, Robert W. Hutkins, Andrew K. Benson

Department of Food Science and Technology: Faculty Publications

Listeria monocytogenes is well known for its durable physiological characteristics, which allow the organism to grow at low temperature and pH and high osmolarity. Growth under high osmolarity depends on the accumulation of compatible solutes, among which glycine betaine and carnitine are the preferred solutes for this organism. Three different transport systems, Gbu, BetL, and OpuC, have been identified in L. monocytogenes which serve to scavenge the preferred compatible solutes. The general stress response regulator σB has been shown to play an important role in osmotic adaptation in L. monocytogenes, presumably by directing transcription from one or more …


Regulation Of Transcription Of Compatible Solute Transporters By The General Stress Sigma Factor, ΣB, In Listeria Monocytogenes, Mehmet Sevket Cetin, Chaomei Zhang, Robert W. Hutkins, Andrew K. Benson Feb 2004

Regulation Of Transcription Of Compatible Solute Transporters By The General Stress Sigma Factor, ΣB, In Listeria Monocytogenes, Mehmet Sevket Cetin, Chaomei Zhang, Robert W. Hutkins, Andrew K. Benson

Department of Food Science and Technology: Faculty Publications

Listeria monocytogenes is well known for its durable physiological characteristics, which allow the organism to grow at low temperature and pH and high osmolarity. Growth under high osmolarity depends on the accumulation of compatible solutes, among which glycine betaine and carnitine are the preferred solutes for this organism. Three different transport systems, Gbu, BetL, and OpuC, have been identified in L. monocytogenes which serve to scavenge the preferred compatible solutes. The general stress response regulator σB has been shown to play an important role in osmotic adaptation in L. monocytogenes, presumably by directing transcription from one or more …


Method For Mulching An Agricultural Soil Bed Using A Biodegradable Protein Material And A Mulched Agricultural Crop Growing Plot Produced Thereby, Yusuf Ali, Viswas Ghorpade, Robert Weber, Milford Hanna Jan 2004

Method For Mulching An Agricultural Soil Bed Using A Biodegradable Protein Material And A Mulched Agricultural Crop Growing Plot Produced Thereby, Yusuf Ali, Viswas Ghorpade, Robert Weber, Milford Hanna

Department of Food Science and Technology: Faculty Publications

A method is provided for mulching an agricultural Soil bed using a biodegradable protein mulch material. The method includes the preparation of a film forming Solution of a film forming protein material. The film forming protein Solution is then sprayed directly onto a Surface of an agricultural Soil bed. The solution dries to form a thin film of protein material on the Surface of the agricultural Soil bed. The protein material may comprise a plant protein, a milk protein, an animal protein, a whey protein, casein, an egg protein or gelatin. Following a harvest, the mulch material, which is biodegradable, …


A Consensus Protocol For The Determination Of The Threshold Doses For Allergenic Foods: How Much Is Too Much?, S. L. Taylor, S. L. Hefle, C. Bindslev-Jensen, F. M. Atkins, C. Andre, C. Bruijnzeel-Koomen, A. W. Burks, R. K. Bush, M. Ebisawa, P. A. Eigenmann, A. Host, Jonathan O. B. Hourihane, E. Isolauri, D. J. Hill, A. Knulst, G. Lack, H. A. Sampson, D. A. Moneret-Vautrin, F. Rance, P. A. Vadas, J. W. Yunginger, R. S. Zeiger, J. W. Salminen, C. Madsen, P. Abbott Jan 2004

A Consensus Protocol For The Determination Of The Threshold Doses For Allergenic Foods: How Much Is Too Much?, S. L. Taylor, S. L. Hefle, C. Bindslev-Jensen, F. M. Atkins, C. Andre, C. Bruijnzeel-Koomen, A. W. Burks, R. K. Bush, M. Ebisawa, P. A. Eigenmann, A. Host, Jonathan O. B. Hourihane, E. Isolauri, D. J. Hill, A. Knulst, G. Lack, H. A. Sampson, D. A. Moneret-Vautrin, F. Rance, P. A. Vadas, J. W. Yunginger, R. S. Zeiger, J. W. Salminen, C. Madsen, P. Abbott

Department of Food Science and Technology: Faculty Publications

Background:While the ingestion of small amounts of an offending food can elicit adverse reactions in individuals with IgE-mediated food allergies, little information is known regarding these threshold doses for specific allergenic foods. While low-dose challenge trials have been conducted on an appreciable number of allergic individuals, a variety of different clinical protocols were used making the estimation of the threshold dose very difficult.

Objective: A roundtable conference was convened to develop a consensus clinical protocol for low-dose challenge trials for the estimation of threshold doses for specific allergenic foods.

Methods: In May 2002, 20 clinical allergists and other interested parties …


Catabolite Repression And Virulence Gene Expression In Listeria Monocytogenes, Stefanie Evans Gilbreth, Andrew K. Benson, Robert W. Hutkins Jan 2004

Catabolite Repression And Virulence Gene Expression In Listeria Monocytogenes, Stefanie Evans Gilbreth, Andrew K. Benson, Robert W. Hutkins

Department of Food Science and Technology: Faculty Publications

Previous studies have suggested that carbohydrates may affect expression of virulence genes in Listeria monocytogenes. Which carbohydrates influence virulence gene expression and how carbohydrates mediate expression, however, is not clear. The goal of this work was to examine how carbohydrates affect virulence gene expression in L. monocytogenes 10403S. Growth studies were conducted in medium containing glucose and various sugars. Metabolism of arbutin, arabitol, cellobiose, mannose, maltose, trehalose, and salicin were repressed in the presence of glucose. Only when glucose was consumed were these sugars fermented, indicating that catabolite repression by glucose had occurred. To determine whether virulence gene expression …