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You searched for +publisher:"Texas A&M University" +contributor:("Andrews-Polymenis, Helene L."). Showing records 1 – 2 of 2 total matches.

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1. Reynolds, Mollie Megan. Identification of Novel Virulence Genes of Salmonella enterica Using an Array Based Analysis of Cistrons Under Selection.

Degree: PhD, Genetics, 2011, Texas A&M University

Pools of mutants of minimal complexity but maximal coverage of genes of interest facilitate screening for genes under selection in a particular environment. Prior to this work, mutants were generated by random transposon insertions, which yielded highly complex pools for in vivo studies. Recent advances in polymerase chain reaction (PCR)-based mutagenesis in bacteria using the lambda red recombinase, as well as whole genome sequencing, enable a more directed approach for the generation of mutants. The lambda red approach was used to construct individual mutants in 1,023 Salmonella enterica serovar Typhimurium genes, including almost all genes found in Salmonella, but not in related genera. All the mutations were confirmed simultaneously using a novel amplification strategy to produce labeled ribonucleic acid (RNA) from a T7 RNA polymerase promoter, introduced during the construction of each mutant, followed by hybridization of this labeled RNA to a Typhimurium genome tiling array. To demonstrate the ability to identify fitness phenotypes using our pool of mutants, the pool was subjected to selection by intraperitoneal injection into BALB/c (Bagg Albino) mice and was recovered from the spleen. Changes in the representation of each mutant were monitored using T7 transcripts hybridized to a novel inexpensive minimal microarray. Among the top 120 statistically significant spleen colonization phenotypes, 51 were mutations in genes with no previously known role in this model. Fifteen phenotypes were tested using individual mutants in competitive assays and eleven were confirmed in individual mixed intraperitoneal infection in mice, including the first two examples of attenuation for sRNA mutants in Salmonella. We refer to our method as Array-Based Analysis of Cistrons Under Selection (ABACUS). Among the confirmed mutants identified in the ABACUS screen was a component of the twin arginine transport (Tat) system, tatC, required for transport of folded proteins across the cellular membrane. TatC is the highly conserved component necessary for recognition of the twin arginine containing signal sequence S/T-R-R-x-FL- K. We confirmed [delta] tatC mutants are defective for colonization of the liver and spleen in competitive infections with wild type ATCC14028 after intraperitoneal infection in Salmonella- susceptible (BALB/c). We also found that [delta] tatC mutants were defective for swimming motility, but not swarming motility, which was linked to the ability to elaborate flagellins on the bacterial surface under different conditions. Advisors/Committee Members: Andrews-Polymenis, Helene L. (committee member), Adams, Garry (committee member), Samuel, James (committee member), Skare, Jonathon (committee member).

Subjects/Keywords: ABACUS; Salmonella; genetic screens; Twin arginine transport; motility

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Reynolds, M. M. (2011). Identification of Novel Virulence Genes of Salmonella enterica Using an Array Based Analysis of Cistrons Under Selection. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-7675

Chicago Manual of Style (16th Edition):

Reynolds, Mollie Megan. “Identification of Novel Virulence Genes of Salmonella enterica Using an Array Based Analysis of Cistrons Under Selection.” 2011. Doctoral Dissertation, Texas A&M University. Accessed March 09, 2021. http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-7675.

MLA Handbook (7th Edition):

Reynolds, Mollie Megan. “Identification of Novel Virulence Genes of Salmonella enterica Using an Array Based Analysis of Cistrons Under Selection.” 2011. Web. 09 Mar 2021.

Vancouver:

Reynolds MM. Identification of Novel Virulence Genes of Salmonella enterica Using an Array Based Analysis of Cistrons Under Selection. [Internet] [Doctoral dissertation]. Texas A&M University; 2011. [cited 2021 Mar 09]. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-7675.

Council of Science Editors:

Reynolds MM. Identification of Novel Virulence Genes of Salmonella enterica Using an Array Based Analysis of Cistrons Under Selection. [Doctoral Dissertation]. Texas A&M University; 2011. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-7675


Texas A&M University

2. Sivula, Christine Patricia. Comparison of cecal colonization of Salmonella enterica serotype Typhimurium in white leghorn chicks and Salmonella-resistant mice.

Degree: MS, Laboratory Animal Medicine, 2009, Texas A&M University

Salmonellosis is one of the most important bacterial food borne illnesses worldwide. Among the many Salmonella serotypes, Typhimurium is the most commonly implicated serotype in human disease in the United States. A major source of infection for humans is consumption of chicken or egg products that have been contaminated with S. Typhimurium. The breadth of knowledge regarding colonization and persistence factors in the chicken is small when compared to our knowledge of factors that are important for these processes in other species used in Salmonella research, such as cattle and mice. Defining the factors important for these processes in the chick is the first step in decreasing the transmission of Salmonella between animal and human hosts. In this work, we developed a chicken model to identify and study intestinal colonization and persistence factors of Salmonella enterica serovar Typhimurium. We studied the degree of enteric and systemic colonization of wild type S. Typhimurium ATCC14028, one of the most widely studied Typhimurium isolates, in White Leghorn chicks and in Salmonella-resistant CBA/J mice during infection. Furthermore, we determined the distribution of wild type S. Typhimurium and a SPI-1 mutant (invA) during competitive infection in the cecum of 1-week-old chicks and 8-week-old mice. Cell associated, intracellular and luminal distributions of these strains in the cecum were analyzed as total counts in each compartment and also as a competitive index. Localization of S. Typhimurium ATCC14028 and the role of SPI-1 in colonization are well studied in murine models of infection, but comparative infection in chicks with the same strain has not been undertaken previously. We show that the cecal contents are the major site for recovery of S. Typhimurium in the cecum of 1-week-old chicks and Salmonella-resistant mice. We also show that while SPI-1 is important for successful infection in the murine model, it is important only for cell association in the cecum of 1-week-old chicks. Finally, we found that in chicks infected at 1 week of age, bacterial counts in the feces do not reflect those seen in the cecum as they do in mice. Advisors/Committee Members: Adams, L. Garry (advisor), Andrews-Polymenis, Helene L. (advisor), Ihrig, Melanie (committee member).

Subjects/Keywords: Salmonella; cecum; SPI-1; chicks; mice

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Sivula, C. P. (2009). Comparison of cecal colonization of Salmonella enterica serotype Typhimurium in white leghorn chicks and Salmonella-resistant mice. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2989

Chicago Manual of Style (16th Edition):

Sivula, Christine Patricia. “Comparison of cecal colonization of Salmonella enterica serotype Typhimurium in white leghorn chicks and Salmonella-resistant mice.” 2009. Masters Thesis, Texas A&M University. Accessed March 09, 2021. http://hdl.handle.net/1969.1/ETD-TAMU-2989.

MLA Handbook (7th Edition):

Sivula, Christine Patricia. “Comparison of cecal colonization of Salmonella enterica serotype Typhimurium in white leghorn chicks and Salmonella-resistant mice.” 2009. Web. 09 Mar 2021.

Vancouver:

Sivula CP. Comparison of cecal colonization of Salmonella enterica serotype Typhimurium in white leghorn chicks and Salmonella-resistant mice. [Internet] [Masters thesis]. Texas A&M University; 2009. [cited 2021 Mar 09]. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2989.

Council of Science Editors:

Sivula CP. Comparison of cecal colonization of Salmonella enterica serotype Typhimurium in white leghorn chicks and Salmonella-resistant mice. [Masters Thesis]. Texas A&M University; 2009. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2989

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