Thesis (Ph.D.)--University of Wyoming, 2008. / Title from PDF title page (viewed on August 5, 2009). Includes bibliographical references (p. 123-138).

No description available.

The influence of the viable but non-culturable (VBNC) state on specific phenotypic traits of Escherichia coli O157:H7 as well as its transport behaviour in porous media was examined in this study. E.coli O157:H7 is a human pathogen capable of entering a VBNC state following exposure to sublethal stress. In the VBNC state, E.coli O157:H7 is not detectable by culture assays; yet, is able to retain its ability to cause human illness. This study examined specific transport-related properties of culturable and VBNC E.coli O157:H7 cells. As well, transport behaviors of the two cellular states were compared using sand-packed columns under steady-state flow. When E.coli O157:H7 cells entered a VBNC state, significant decreases in the hydrophobicity and lengths/widths of the cells, and a significant increase in extracellular polymeric substances on the cell surfaces were measured. Transport experiments indicated significantly (p<0.05) greater mass transport of VBNC cells through unwashed sand compared to culturable cells. This research contributes to the current knowledge describing VBNC E.coli O157:H7 cells, raises questions concerning the accuracy of culture-based E.coli O157:H7 identification protocols, and suggests that bacteria transport in the subsurface is a truly dynamic process. / Soil Science

Thesis (M.Sc.)(Food Science)--University of Pretoria, 2008. / Includes summary. Includes bibliographical references. Available on the Internet via the World Wide Web.

Thesis (Ph. D.)--University of Texas at Austin, 1999. / Vita. Includes bibliographical references (leaves 132-158). Available also in a digital version from Dissertation Abstracts.

Thesis (M. S.)--Montana State University--Bozeman, 2005. / Typescript. Chairperson, Graduate Committee: John Paterson. Includes bibliographical references (leaves 58-68).

Thesis (Ph.D.(Food science))-University of Pretoria, 2009. / Includes bibliographical references. Availalble in print and online.

Thesis (Ph.D.)--Aberdeen University, 2009. / Title from web page (viewed on June 3, 2009). Includes bibliographical references.

No description available.

Cattle are naturally colonized by enterohemorrhagic Escherichia coli within the gastrointestinal tract. The most notorious of the enterohemorrhagic E. coli is E. coli O157:H7, which can cause serious illness to humans if ingested. To ensure that the United States has a safe food supply, research is ongoing in pre-harvest food safety and pathogen intervention strategies. While advances in pre-harvest intervention strategies are encouraging, no method has proven to completely eliminate and/or control O157:H7. A key limitation to successful pathogen intervention strategies is the inability to track and monitor pathogens in a real-time fashion. Through the use of bioluminescent plasmids harboring the luxCDABE cassette, pathogen tracking could be a viable solution. Bioluminescent plasmids are capable of facilitating the tracking, pathogenesis and physical locations of pathogens, thus enabling researchers to have a better understanding of the pathogenic process.