creator Megalis, Christina Salmonella is a growi ng concern in low-moisture foods. The objective of this project is to further unlock the mechanism for Salmonella desiccation survival. Salmonella Tennessee and Typhimurium LT2 were used in this study, each demonstrating a strong and weak resistance to desiccation , respectively. Exponential phase cells were desiccated (RH= II %) for 5 days on steri le paper discs and were reduce d by 4 and 7-logs CFU/mL, respectively. This study examined the role of rod/cocci conversion in Salmonella stress res istance using an SEM. The typical rod-shape of Salmonella was altered upon a 5-day desiccation treatment (aw=O. l l), produ cing a cocci shape and significantly more so in the case of S. Tennessee. S. Tennessee fresh and desiccated cell lengths were 1.32 ± 0.12 and 1.14 ± 0.07 urn, respectively, compared to S. LT2 fresh and desiccated that were 1.55 ± 0. 19 and 1.42 ± 0.14 urn, respectively. Scatter plot analysis showed that the convers ion from rod shape to cocci occurred at greate r extent in S. Tennessee than S. Typhimurium LT2 responding to the 5-day desiccation treatment Cytoskeletal genes involved in cell elongation (rodA, rodZ, mrdB, mreB, mrdA, mrcA, and mrcB) were anal yzed for expression using qRT-PCR. The gene expression profile for the two strain s significantly differed with S. Tennessee virtually having no change in expression after 24-hour desiccation while S. LT2 exp ression ranged from 38 to 91-fold up-regulated . This thesis provided additiona l understanding of Salmonella desiccation resistant strategy; however, to fully understand the expression change of those genes, study of gene expression at different time point is needed in future. Submitted by Liana Khananashvili (khananashvili@iit.edu) on 2013-11-13T22:19:29Z No. of bitstreams: 1 MEGALIS Thesis 7-13.pdf: 14144436 bytes, checksum: 731ca4149d1403febe1defca06239294 (MD5) Made available in DSpace on 2013-11-13T22:19:29Z (GMT). No. of bitstreams: 1 MEGALIS Thesis 7-13.pdf: 14144436 bytes, checksum: 731ca4149d1403febe1defca06239294 (MD5) Previous issue date: 2013-07 M.S. in Food Safety and Technology, July 2013 2013 2013-07 http://hdl.handle.net/10560/3152 en Thesis born digital application/pdf In Copyright http://rightsstatements.org/page/InC/1.0/ Restricted Access NCFST / National Center for Food Safety and Technology Illinois Institute of Technology Affiliated department