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
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:AEU.10048/1934 |
| Date | 11 1900 |
| Creators | Kartz, Cory |
| Contributors | Kachanoski, Gary (Renewable Resources), Dyck, Miles (Renewable Resources), Mendoza, Carl (Earth and Atmospheric Sciences) |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | en_US |
| Detected Language | English |
| Type | Thesis |
| Format | 1105954 bytes, application/pdf |
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